3G Ericsson
3G Ericsson Optimization
and Planning’s Concepts,
Commands, and Case
Studies
Improve your Experience
as a Senior 3G Optimization
Engineer
Based on my experience as an RF optimization engineer, this data has been collected
for a couple of years, and it has been grown step by step. The last update was about
2017, but I think it is valuable to share for someone who wants to improve his/her
experience in 3G RF optimization to the senior level.
Or, someone who is going to plan for an interview.
These used cases have been implemented in a live Ericsson Network, but most of
them are common in different vendors.
It includes:
•
3G Fundamental
•
Features implementation results and suitable parameters' value
•
Optimization Activities’ result
•
Important and useful tools:
•
•
•
WNCS: WCDMA Neighboring Cell Support
MRR-W: Measurement Result Recording for WCDMA
FFAx-W: Find Faulty Antenna Expert for WCDMA
Mohammad Rasoul
Tanhatalab
RAN Performance and Optimization Specialist and
Data Scientist
I have hands-on experience in Mobile RAN
Performance and Optimization areas for over 10
years. Besides, I am passionate about Machine
Learning and Data Science techniques with 5+ of
experience. I have 5 stars rank on HackerRank.com
as a senior Python developer, furthermore,
proficient knowledge in AI, Machine Learning,
Tensorflow, Deep Learning, Statistics, Mathematics,
and Analytics. And, I have published over 18 papers
in International conferences.
For More Information: www.sam-set.com
WhatsApp: +989022700760
Conducted Projects on 3G Throughput
https://ieeexplore.ieee.org/document/7967048
https://ieeexplore.ieee.org/document/8250037
WCDMA RAN Optimization activity
• Consistency Check
 Parameters
 Neighbor definition
•
• Statistics
•
• Alarms
•
• Cell Availability
•
RRC Establishment
RAB Establishment
•
•
•
•
CS DCR
PS DCR
RRC Drop Rate
RAB Drop Rate
Call Setup Success Rate
PS setup success rate (EUL, HSDPA, R99)
• BLER /BER
• Throughput
•
•
•
•
•
HO performance
Neighbor Relations
SHO/ISHO Success Rate
SHO Overhead
HDSPA/HSUPA SCC success rate
Retainability
The probability that a service, once obtained, will continue to be
provided under given conditions for a given time duration. The
percentage of the successfully call setups that were retained
during the whole conversation (session) and terminated by the
user. The standard KPI for retainability is the Dropped Call Rate.
On cell level it is defined as the number of dropped calls in the
cell divided by the total number of calls terminated (by enduser or dropped) in the cell.
Integrity
The degree to which a service is provided without excessive
impairments, once obtained The Service Integrity represents
the quality experienced by the user during the call or session.
This is very difficult to measure from a system point-of-view
and rough measures have to be used, based on RBS and UE
measurements. BLER is used as an indication of the service
integrity for CS services, but do not show the quality
experienced by the end-user. For PS services are BLER and
throughput used as service quality indicators.
Accessibility
The ability of a service to be obtained, within specified
tolerances and other given conditions, when requested by the
user. It is the percentage of call attempts made by the end-user
that are successful. Call setup failures can be blocked calls due
to lack of network resources on various levels, for example
Transmission Network, Channel Elements, DL Power and so on,
or other reason that prevented a successful call setup, for
example radio link problem, signaling failure and so on.
Mobile Call Setup
•
UE IN IDLE MODE
–
–
–
–
–
•
PLMN SELECTION
CELL SELECTION
LA AND RA UPDATE
PAGING
SYSTEM INFORMATION
RANDOM ACCESS
– UL OPEN LOOP POWER CONTROL
•
RRC CONNECTION SETUP
–
–
–
–
–
–
•
EMERGENCY CALLS
MODULE MP LOAD
ADMISSION CONTROL BLOCK
LACK OF TRANSMISSION RESOURCES
LOAD SHARING
RADIO LINK SETUP
NAS PROCEDURES
– CM SERVICE REJECT
•
RADIO BEARER SETUP
– UE CELL RESELECTION DURING HANDOVER
– UE CELL RESELECTION
RRC CONNECTION SETUP
Random Access Procedure
Connection
established
with minimum
interference
to other users
Dedicated channel at just enough power
UE 1
1) UE2 measures Pilot channel
2) UE2 Reads
interference level from
Broadcast channel
The power is ramped up
until a response is heard
or maximum number of
re-attempts is reached
UE 2
RBS
What is the main difference between 3G and 2G
Ec/No, RSCP and RSSI
Ec/No signifies the level difference between
received pilot signal and the overall noise floor.
No is the noise floor, which signifies all the
signals (useful and interfering) present at the
receiver side.
For example: A value of Ec/No= -8dB tells us
that the spread signal is 8 dB below the noise
floor
RSCP : Received Signal Code Power is the
received power on one code after dispreading,
defined on the pilot symbols.
Ec/No = RSCP/RSSI
RSSI It is the combination of all signals received on
the downlink frequency ( in FDD mode ) of the
WCDMA system. As such it is also referred to as
the total noise on the downlink . It is the
equivalent of RTWP on the uplink.
RSSI :
Includes all components received. Including the signals from
the current and neighbors on the same frequency
What is the difference between Scrambling,
Spreading and Channelization Codes
Spreading Code = Channelization Code
Chip rate is consistence and is 3.84 Mcps then we need the 3.84 MHz
Cell breathing phenomena
PS and CS traffic
pmDlTrafficVolumePsCommon: Payload traffic in the
downlink for the PS RAB on FACH, excluding SRB
Erlang_PKT Vs. Elang_Speech
ERLANG_PKT_HS (PMSUMBESTPSHSADCHRABESTABLISH / 720)
Sum of all sample values recorded during a ROP for the number of A-DCH radio bearers established in the caell carrying HS-DSCH in the active set.
Condition: Values are read periodically from an internal level counter and added to this counter.
The level counter maintains the current number of A-DCH radio bearers established in the cell carrying HS-DSCH in the active set for which this cell is the
best cell.
Erlang_3G_Speech
nvl(pmSumBestCs12Establish,0) / (3600/5)+ nvl(PMSUMBESTAMR12200RABESTABLISH,0) / (3600/5)+ nvl(PMSUMBESTAMR4750RABESTABLISH,0) /
(3600/5)+ nvl(PMSUMBESTAMR5900RABESTABLISH,0) /(3600/5) + nvl(PMSUMBESTAMR7950RABESTABLISH,0) /(3600/5)
DATA COLLECTION
Performance Statistics are continuously collected from all Network Elements (NE) and stored persistently in Operation Support System, Radio and Core
(OSS-RC). Statistics are mainly used for the detection of problem areas and for monitoring the performance of the network on a daily basis. The complete
WCDMA Radio Access Network (RAN)Performance Management (PM) functionality receives support
from all WCDMA RAN nodes:
• Radio Base Station (RBS)
• Radio Network Controller (RNC)
• Radio Access Network Aggregator (RANAG – RXI)
• OSS-RC.
The traffic nodes provide the performance information through a file interface. This information is collected by OSS-RC.
HSPA Air interface
3G Air interface
3G Channels
Manage Object Overview
An MO represents a resource in the node, either a
physical resource such as a plug-in unit or a logical
resource such as a software program or a protocol. In
either case, there are parameters associated with
the resource, called MO attributes
SRNC, DRNC, RAB, RB and RL
SRNC and DRNC
SRNC and DRNC are concepts for a connected UE. The SRNC handles
the connection to one UE, and may borrow radio resources of a
certain cell from the DRNC.
Drift RNCs support the Serving RNC by providing radio resources A UE
in connection state has at least one and only one SRNC, but can has 0
or multiple DRNCs
RAB, RB and RL in WCDMA
RAB: The service that the access stratum provides to the non-access
stratum for transfer of user data between User Equipment and CN.
RB: The service provided by the layer2 for transfer of user data
between User Equipment and Serving RNC.
RL: A “radio link” is a logical association between single User
Equipment and a single UTRAN access point. Its physical realization
comprises one or more radio bearer transmissions.
PM prefix
Random Access Parameters
•
•
The Random Access Procedure is utilized by the UE to access the UTRAN network from an Idle, or Cell_FACH state
Check RACH parameters to look for a wrong setting:
•
•
•
•
•
•
•
aichPower
powerOffsetP0
powerOffsetPpm
preambleRetransMax
maxPreambleCycle
constantValueCprach
maxTxPowerUl
Admission control
Admission control is used in both the
uplink and downlink. The admission
decision is based on air interface
load, by using measurements of
uplink interference, downlink output
power as well as the actual number
of users.
There are nine admission policies to
control the blocking.
1.
2.
3.
4.
5.
6.
7.
8.
9.
UL ASE
DL ASE
DL TX cell power
spreading factor usage
code usage
HW usage
amount of HS users
congestion
number of users in
compressed mode
Admission Control has different policies
The counter pmNoReqDeniedAdm shows the number of RRC establishment requests and RAB
establishment requests denied for a cell. Please note that this counter is stepped up for RRC
establishment, RAB establishment or channel up-switching if admission control triggers the blocking in
a cell. The solution to the admission control blocking problem is to check if the admission thresholds
(i.e. ulHwAdm, hsdpaUsersAdm , maximumTransmissionPower, aseUlAdmOffset, beMarginAseDl,
beMarginAseUl, beMarginDlCode, compModeAdm, dlCodeAdm) match to the original planned
capacity. If the thresholds do not match to the original planned capacity, the admission thresholds
have to be corrected. Otherwise, re-do the radio network dimensioning to increase the system
capacity or activate the inter-frequency load sharing to increase the trucking efficiency.
RRC Connection Request/Setup
RRC:RACH/CCCH : RRC Connection Request
RRC:FACH/CCCH : RRC Connection Setup
• FACH1 is used to carry control information
• Parameter maxFach1Power [-35.0..+15.0] dB
• Increasing the power of FACH1 will have higher probability to receive
RRC Connection Setup especially in low coverage areas.
Change maxFach1Power from 18 to 38 (1.8 dB  3.8 dB)
Notes: this setting is not recommended for high capacity cells
Pilot Pollution
• When the number of strong cells exceeds the Active Set Size (How many Cells
can be on Soft Handover with a UE), There becomes pilot pollution in the area.
• Typically the active set size is 3, so if there are more than 3 strong cells then
there is pilot pollution.
• Definition of “strong cell”: pilots within the handover window size from the
strongest cell. Typical handover window size is between 4 to 6dB. (Depends
generally Event1b Removal Range)
• For example, if there are more than 2 cells (besides Active Set Cells) within 5dB
of the strongest cell then there is pilot pollution.
• The UE has the ability to constructively use signals in soft/softer handover, all the
other signals received that exceeds the Active Set act as interfering. This
interference degrades the performance of the system.
Call Setup Failure Analysis Process__DT
The on-Air site did not define in OSS
find by O&M IP
Resources to be monitored
• RF Power
– Lack of Downlink Power (pmNoFailedRabEstAttemptLackDlPwr)
• Code Tree Consumption
– Lack of Canalization Code (pmNoFailedRabEstAttemptLackDlChnlCode)
• RRC level code
– Lack of Canalization Code (pmNoRrcreqdeniedAdmDlChanlCode)
• DL and UL ASE
– Lack of Downlink ASE (pmNoFailedRabEstAttemptLackDlAse)
– Lack of Uplink ASE (pmNoFailedRabEstAttemptLackUlAse)
• SF Code Limit (Code Hystogram)
– Exceed SF histogram (pmNoFailedRabEstAttemptExceedConnLimit)
• HSDPA and EUL connections Limit
• UL and DL Channel Elements (CE)
– Lack of DL Channel Elements (pmNoFailedRabEstAttemptLackDlHw)
– Lack of UL Channel Elements (pmNoFailedRabEstAttemptLackUlHw)
Power Congestion (RRC Denied)
pmNoRrcReqDeniedAdm
Number of RRC requests
denied by admission control.
The counter is trigged when
an RRC connection request
with any cause value is
denied by Admission Control
pmNoRrcReqDeniedAdmDlPwr
Number of RRC Connection
Requests denied by
admission control due to lack
of DL Power.
Power Congestion (RAB attempt failed)
pmNoFailedRabEstAttemptLackDlPwr
Number of RAB establishment
attempts that failed due to lack
of downlink power.
PWR congestion due to locked third carrier
configurations
Congestion Issue
pmNoOfSwDownNgAdm
Number of downswitch requests for nonguaranteed and guaranteed-hs users served by this
RNC due to admission control
Condition:
Incremented
by
one
when
downswitching from Cell_DCH 64/384->64/128 or
Cell_DCH 64/128->64/64 initiated by admission
control to do Best Effort Cleanup. This is done after
an admission rejection due to insufficient downlink
power or code utilization limits. The connection to
switch down is selected if it is a non-guaranteed
and non-drifting connection with a lower spreading
factor than that of the latest requested radio link.
The counter is incremented in the cell which had to
reject admission.
Idle Behavior (2G and 3G)
Parameters QSI (Quality Search Index) and QSC define thresholds and indicate when UTRAN measurements shall be performed (for start
of UTRAN FDD measurements in idle mode). QSI is used for idle and packet switched modes and broadcast on BCCH, while QSC is used for
active mode, sent on SACCH. It is better to finish the CS call first and then do the IRAT cell reselection.
For (0-6) the UE searches for UTRAN cells if the signal level is below the threshold. For (8-14) for above the threshold
2G Command: rlsup:cell=“cell-name”;
Feature activation in BSC
The feature GSM-UMTS Cell Reselection and Handover is activated per BSC with the exchange property COEXUMTS.
COEXUMTS is used to enable the features GSM-UMTS Cell Reselection and Handover, Combined Cell Reselection
Triggering and Combined Handover Triggering GSM to WCDMA. The parameter is a BSC exchange property.
– 0 OFF ; GSM-UMTS Cell Reselection and Handover and Combined Cell Reselection Triggering GSM to WCDMA are not
activated.
– 1 ON; GSM-UMTS Cell Reselection and Handover is activated.
– 2 ONADDINFO; GSM-UMTS Cell Reselection and Handover and Combined Cell Reselection Triggering GSM to
WCDMA are activated
– 3 ONADDINFO; GSM-UMTS Cell Reselection and Handover and Combined Handover Triggering GSM to WCDMA are
activated
– 4 ONADDINFO; GSM-UMTS Cell Reselection and Handover, Combined Cell Reselection Triggering GSM to WCDMA
and Combined Handover Triggering GSM to WCDMA are activated
• BSC Command: raepp:ID=all;
2G to 3G cell reselection based on cell Ranking
The algorithm for cell reselection to UMTS is controlled by the
network with the parameters FDDQMIN and FDDQOFF
• A Multi-RAT capable UE will reselect a suitable UTRAN cell if the
following criteria are fulfilled :
– CPICH Ec/No > FDDQMIN &
– CPICH RSCP > RLA(s+n) + FDDQOFF
– for a period of 5 seconds. (RLA(s+n) = Received Level Average of serving
and neighboring GSM cells)
3G CELL SELECTION
The UE bases its evaluation on two quantities: Squal and
Srxlev. The cell selection criteria are fulfilled when:
– Squal = Qqualmeas- qQualMin > 0
– Srxlev = Qrxlevmeas – qRxLevMin – Pcompensation > 0
Where Pcompensation = max(maxTxPowerul – P;0)
•
•
•
qQualmin and qRxLevMin is sent in the broadcast information (SIB 3
for serving cell and SIB 11 for adjacent cells)
maxTxPowerUl is the maximum transmission power during random
access on the RACH and that value is sent in the system information
(SIB 3).
P is the UE maximum output power according to its class.
The UE measures the received signal Code Power (CPICH RSCP)
and the received quality, on the CPICH (CPICH Ec/No) obtains Srxlev and
Srxlev. If both criteria are fulfilled and other requirements for a suitable
cell are fulfilled the UE will camp on the cell. The UE will enter
the state “camped normally” where it performs intra-, inter- and
intersystem radio measurements to evaluate if a neighboring cell
is better than the serving one.
CHANNEL SWITCHING
Channel Switching Fundamental
Each channel (FACH/RACH/DCH) requires resources that are “fixed” allocated to that channel
(such as DL channelization codes, RBS hardware, RAKE receivers, coding processors etc).
Regardless if the channel is used or not the resources allocated to that channel cannot be used
by another channel. In the RNC each user has resources allocated but the most limiting
resources are the air interface resources (interference/power and the RBS hardware) so it is
important to optimize the usage of these as much as possible.
• The logical channels, DCCH and DTCH, are mapped onto the DCHs and further onto
Dedicated Physical Channels. These physical channels use inner-loop power control.
• In the common state the UE is able to transmit control signals and data packets on the
common transport channel RACH. The UE also monitors the FACH to receive downlink
information. The logical channels, DCCH, CCCH, and DTCH are mapped onto the RACH and
the FACH. These channels are suitable for carrying common control information and are
shared by all users in the cell. A maximum of 32 kbit/s is available for user data
transmission.
Best Effort (BE) users are
handled
by
‘Channel
Switching’ in the WCDMA
RAN. Both channel type and
channel rate switching are
supported. The channel
type switching is based on
throughput and buffer sizes.
The rate switching can be
triggered by Admission
control, Soft Handover and
coverage reasons
There are 8 types of channel switching:
1.
2.
3.
4.
5.
6.
7.
8.
RBS Capacity will calculate with Cell_DCH Users
Common to Dedicated Evaluation
Dedicated to Common Evaluation
DCH-DCH Up-Switch Evaluation
DCH-DCH Down-Switch Evaluation
Common to Idle Evaluation
Multi-RAB Up-switch Evaluation
Multi-RAB Down-switch Evaluation
Down switch: Handover Based
•
Cell_DCH State
–
–
–
–
–
–
•
Cell_FACH State
–
–
–
–
•
No dedicated physical channel is allocated to the UE.
The UE continuously monitors a FACH in the downlink.
The UE is assigned a default common or shared transport channel in the uplink (RACH or CPCH) that it can use anytime according to the access
procedure for that transport channel.
The position of the UE is known by UTRAN on cell level according to the cell where the UE last made a cell update.
Cell_PCH
–
–
–
–
–
•
A dedicated physical channel is allocated to the UE in uplink and downlink.
The UE is known on cell level according to its current active set.
Dedicated transport channels, downlink and uplink (TDD) shared transport
channels, and a combination of these transport channels can be used by the UE.
The Cell_DCH state is entered from the Idle Mode through the setup of an RRC
connection, or by establishing a dedicated physical channel from the Cell_FACH state.
No dedicated physical channel is allocated to the UE.
The UE uses DRX for monitoring the selected PCH via an associated PICH.
No uplink activity is possible.
The position of the UE is known by UTRAN on cell level according to the cell
where the UE last made a cell update in Cell_FACH state.
URA_PCH
–
–
–
–
No dedicated channel is allocated to the UE.
No uplink activity is possible.
The location of the UE is known on UTRAN Registration Area (URA) level according to the URA assigned to the UE during the last URA update in
Cell_FACH state.
If the network wants to initiate any activity, it needs to make a paging request on the PCCH logical channel within the URA where the location of the
UE is known.
Power Control
Why the WCDMA use Power Control:
• Minimize the UL-Interference
• Minimize the DL Transmit Power
• Share resource in WCDMA
• Keeping connection quality
• Compensating channel destructive
effects like attenuation, fading ..
• Battery life time improvement in UE
WCDMA Power Control loops working together (UE
example)
Power Control
Setting Common Channel
Powers
Sharing Power
Pilot Channel Power
•
•
•
•
•
•
primary CPICH power should be 8 to 10% (~ 1 Watt) of the
nominal RBS power at the reference point (~10W, while MCPA
is 20W)
The pilot power is designed to be equal in all cells at the
Reference Point.
– primaryCpichPower = 30 dBm
– TopOfRack = primaryCpichPower + dlAttenuation
System will adjust the TopOfRack to meet the required value.
Consistency check on MaximumTransmissionPowerDL
(Calculated vs. setting value)
The feeder loss parameters ulAttenuation & dlAttenuation
and electrical delay parameters ulElectricalDelay &
dlElectricalDelay must be entered properly in the system
(actual VSWR).
More CPICH – less capacity trade off
P-CPICH
dl/ulAttenuation
dl/ElectDelay
TopOfRack
set UtranCell=9546XA primarycpichpower 330
MaxTxPowerDL
To see Max DL Power Capability
Carrier
maxDlPowerCapability
long
readOnly,nonPersistent
-----------------------------------------------------------------------------------------------------------------------------------The maximum downlink power capability for the carrier.
Unit: 0.1 dBm
Undefined value: -1
Range: -1 to 500
************************************************************************************************************************************
RbsLocalCell
maxDlPowerCapability
long
readOnly,nonPersistent
-----------------------------------------------------------------------------------------------------------------------------------The maximum downlink power capability for the cell. For a cell using more than one carrier, this value is the maximum DL power capability among the carriers. The
attribute value is reported to the RNC.
Unit: 0.1 dBm
Undefined value: -1
Specification: 3GPP TS 25.433, NBAP, UTRAN Iub interface NBAP signalling
Range: -1 to 500
To see Antenna Feeder Capability
CPICH power
• Dependencies:
Effect of Change: Change of this parameter effects pilot coverage e.r. handover areas,
interference areas, traffic coverage areas. Too low value can lead to appearance of
“coverage holes”. Too high value can lead to “near–far” effect or that cell is taking too
much traffic. In the loaded co-sited network it can be that some problems we will be
solving changing this parameter.
• Troubleshooting:
This parameter should be investigated when the following problems are observed :
Pilot Channel failure due to high downlink interference ( Possible causes: No dominant cell, Dominant
interferer, Low best serving EcIo);
Pilot Channel failure – out of pilot coverage (Possible causes: Low pilot channel power);
Pilot pollution (Possible causes: No dominant cell);
Uplink and Coverage pilot imbalance ( Possible causes: Large pilot power, UE in compressed mode);
Uneven load distribution (Possible cause: Homogenous pilot setting in an irregular network),
Random access procedure problem (Possible cause: PRACH and Pilot coverage imbalance) Handover
Common Control Channel Power
•
•
With increasing CPICH power – capacity directly decreasis, but common channels and power per
each dedicated channel is calculated from CPICH
At CPICH 30 dBm, the common channel will be configured as follow:
Parameter Name
primaryCpichPower
MO Type
UtranCell
pchPower
Pch
primarySchPower
Value
Cumm(dBm)
Peak Power(W)
Typical AF
Avg Power(W)
30
1
1
1
-0.4
29.6
0.91
0.20
0.18
UtranCell
-1.8
28.2
0.66
0.10
0.07
secondarySchPower
UtranCell
-3.5
26.5
0.45
0.10
0.04
maxFach1Power
Fach
1.8
31.8
1.51
0.10
0.15
maxFach2Power
Fach
1.5
31.5
1.41
0.30
0.42
bchPower
UtranCell
-3.1
26.9
0.49
0.90
0.44
aichPower
Rach
-6
24
0.25
0.10
0.03
pichPower
Pch
-7
23
0.20
1.00
0.20
38.38
6.89

MaximumTransmissionPowerDL is design to be equal with Nominal RBS Power
2.53
Common Channel on Downlink
Cell Setup and Reconfiguration - Downlink
primaryCpichPower
is the power used for transmitting the PCPICH.
bchPower
is the power used for transmitting on the BCH, relative to the primaryCpichPower value.
primarySchPower
is the power used for transmitting on the Primary SCH, relative to the primaryCpichPower value.
secondarySchPower
is the power used for transmitting on the Secondary SCH, relative to the primaryCpichPower value.
Common Transport Channel Setup and Reconfiguration - Downlink
aichPower
is the power used for transmitting on AICH, relative to the primaryCpichPower value.
maxFach1Power
defines the maximum power used for transmitting the first FACH channel, relative to the
primaryCpichPower value. The first FACH is used for logical channels BCCH, CCCH, and DCCH
control signaling.
maxFach2Power
defines the Maximum power used for transmitting the second FACH channel, relative to the
primaryCpichPower value. The second FACH is used for logical channel DTCH traffic signaling.
pOffset1Fach
is the offset between downlink DPDCH and DPCCH TFCI field on FACH.
pOffset3Fach
is the offset between downlink DPDCH and DPCCH pilot field on FACH.
pchPower
is the power used for transmitting on the PCH, relative to the primaryCpichPower value.
pichPower
is the power used for transmitting on the PICH, relative to the primaryCpichPower value.
Common Channel on Uplink
Common Transport Channel Setup and Reconfiguration - Uplink
constantValueCprach
is a constant value in dB used by the UE to calculate the initial power on the PRACH according to
the Open Loop Power Control procedure.
powerOffsetP0
is the Power ramp step for the preamble when no acquisition indicator is received.
powerOffsetPpm
is the Power offset between the last transmitted preamble and the control part of the random
access message.
preambleRetransMax
is the maximum number of preambles sent in one RACH preamble ramping cycle.
maxPreambleCycle
is the maximum number of preamble ramping cycle.
Preamble Power
P_RACH
The initial power on the PRACH - the power of the first preamble - is determined according to equation
P_PRACH = L_PCPICH + RTWP + constantValueCprach (-27dB)
Received Total Wideband Power
(RTWP)
All transmissions in the uplink contribute to the
increase in uplink noise, or Received Total Wideband
Power (RTWP). To limit the interference a UE can
create, the parameter maxTxPwrUl is used to control
the maximum power the UE can transmit. This
parameter is typically configured to be 24 dBm for a
Class 3 UE.
L_PCPICH
: is the path loss estimated by the UE based on knowing the
transmitted and received PCPICH power.
RTWP
: is the Received Total Wideband Power (uplink
interference) level measured by the RBS.
constantValueCpra
ch
: is used by the UE to calculate the initial power on the
PRACH . This parameter is configurable and decides at
which level below RTWP preamble ramping will start
POWER RAMP ON RACH
To reach an appropriate received power level at the RBS, the UE uses preamble ramping. This procedure consists of the
following steps:
•
The UE transmits a preamble.
•
As soon as the RBS properly detects the preamble, it sends an Acknowledgement Indicator (AI) on the AICH.
•
While not receiving any AI, the UE transmits a new preamble, increasing the transmission power with respect to the
previous one by the configurable parameter powerOffsetP0.(3dB)
•
As soon as the UE receives an AI, it sends the PRACH message part. The power of the control part of the random access
message is determined by the power of the last transmitted preamble and by a configurable offset powerOffsetPpm.(- 4dB)
The power of the data part of the PRACH message is determined by the gain factors for PRACH, which is included in
System Information.
Common Channel on Uplink
POWER RAMP ON RACH

preambleRetransMax parameter determines how many times
PRACH preamble can be sent within one preamble ramping cycle
(SIB5&6)

maxPreambleCycle defines how many times the PRACH preamble
ramping cycle procedure can be repeated before UE MAC reports a
failure on RACH transmission to higher layers (SIB5&6)
L1 ACK / AICH
In average coverage conditions
the RRC Connection Setup
performance can be improved
by tuning the open loop power
control parameters
These parameters are
preambleRetransMax
and & maxPreambleCycle
powerOffsetPpm
powerOffsetP0
Downlink Not detected
BS
MaxTXPowerUl
powerOffsetP0
Initial
preamble
power
……
Uplink
Preamble
MS Preamble
1
2
……
Preamble
preambleRetransMax
# PRACH preambles transmitted during one PRACH
cycle without receiving AICH response
maxPreambleCycle
# preamble power ramping cycles that can be done
before RACH transmission failure is reported
powerOffsetPpm
Message part
Find some KPIs formula which are defined in RNC
HSPA+ and EUL
Main difference in performance between R99
Packet and HSDPA
• R99 Packet service requires dedicated channels whereas
HSDPA users have a shared channel
• Speeds of HSDPA are much higher compared to 3G(R99). In
real networks, an average HS subscriber gets around 5-8 times
throughput, compared to an R99 data user.
HSDPA Physical and Transport Channels
To support HSDPA new Physical channels have been defined:
HS-PDSCH or High Speed Physical Downlink Shared Channel: This is a downlink channel which is both time and code multiplexed.
The channelization codes have a fixed spreading factor, SF = 16.
Multi-code transmissions are allowed that translates to UE being assigned multiple channelization
codes in the same TTI, depending on the UE capability. The same scrambling code sequence
is applied to all the channelization codes that form the single HS-DSCH CCTrCH.
If there are multiple UE's then they may be assigned channelization codes in the same TTI (multiplexing of multiple UE's in the code
domain).
HS-DPCCH or High Speed Dedicated Physical Control Channel: This is an uplink channel that
carries the Acknowledgements of the packet received on HS-PDSCH and also the CQI (Channel Quality Indication). THE CQI estimates
have to be transmitted by the UE every 2.0 ms frame. This information is very important as it ensures reliability and impacts power capacity.
HS-SCCH or High Speed Shared Control CHannel: The HS-SCCH is a fixed rate (60 kbps, SF=128) downlink physical channel used to
carry downlink signaling related to HS-DSCH transmission. This provides timing and coding information thus allowing the UE to listen to the
HS-DSCH at the correct time and using the correct codes to allow successful decoding of UE data.
The main features of the physical channel are as follows:
Fixed Spreading Factor of 16 for HS-DSCH
QPSK and 16 QAM Modulation
Static TTI Length of 3 Time Slots = 2ms
Fixed CRC of 24 bits
Error Correction using 1/3 Turbo Coding
To support HSDPA the following new Transport channels have been defined:HS-DSCH or High Speed Downlink Shared channel: The High
Speed Downlink Shared Channel is a downlink transport channel shared by several UEs. The HS-DSCH is associated with one downlink
DPCH, and one or several Shared Control Channels (HS-SCCH). The HS-DSCH is transmitted over the entire cell or over only part of the
cell using e.g. beam-forming antennas.
HS Characteristics
• Spreading Factor in HSDPA is fixed to 16 and it is not adaptive
• Multi-code can be allocated to one user, for example 4
channelization codes of SF=16 can be allocated to a user.
• Maximum 15 codes can be used in HSDPA
• The number of codes used per user depend on reported CQI
• Codes allocated to user only when possible to be used
• RBS dynamically allocates the codes to the users every 2 ms
HSDPA Multi Code Transmission
SF=1
SF=2
SF=4
SF=8
SF=16
Remaining codes used for signalling
15 x SF16 => 15(3.84X106/16) = 3.6X106 symbols/sec
QPSK (2bits/symbol) => 3.6X106 x 2 = 7.2 Mbps
Physical rates
16QAM (4bits/symbol) => 3.6X106 x 4 = 14.4 Mbps
64QAM (6bits/symbol) => 3.6X106 x 6 = 21.6 Mbps
64QAM (6bits/symbol) => 3.6X106 x 6 x 2 = 43.2 Mbps (MIMO)
HSDPA Scheduling
2 msec TTI
Scheduling Algorithm
HSDPA
codes
User #1
User #2
User #3
• EQUAL_RATE [5]
• MAXIMUM_CQI [4]
• PROPORTIONAL_FAIR_HIGH [3]
• PROPORTIONAL_FAIR_LOW [2]
• PROPORTIONAL_FAIR_MEDUM [1]
• ROUND_ROBIN [0]
User #4
HSDPA shared channel:
- shared in time (2 msec TTI)
- codes shared between users
(4 users per TTI)
• Multi-code transmission, UE is assigned
to multiple codes in the same TTI
• Multiple UEs may be assigned
channelization codes in the same TTI
numHsScchCodes
The parameter numHsScchCodes controls the number of HSSCCH broadcast per cell. The number of HS users that can be
simultaneously allocated resources by the scheduler per 2 ms
Transport Time Interval (TTI) is directly related to the number of
HS-SCCH broadcast (maximum is 4).
If a cell has a high HS traffic load, and a low DCH load, it may be
beneficial to increase the number of broadcast HS-SCCH.
However, if the overall cell throughput is limited due to power,
HS-PDSCH codes or transport limitations, consuming another
128 bit code to support an additional HS-SCCH is unneeded.
# Users Per Cell
HSDPA throughput meets theory
R99 Channels Vs. HSDPA
HSDPA Channels
• HS-PDSCH
– Carries the data traffic
– Fixed SF = 16; up to 15 parallel channels
– QPSK: 480 kbps/code, 16QAM: 960 kbps/code
• HS-SCCH
– Signals the configuration to be used next: HS-PDSCH codes, modulation format, TB
information
– Fixed SF = 128
– Sent two slots (~1.3msec) in advance of HS-PDSCH
• HS-DPCCH
– Feedbacks ACK/NACK and channel quality information (CQI)
– Fixed SF = 256, code multiplexed to UL DPCCH
– Feedback sent ~5msec after received data
3G Resources
•
•
The term channel element (CE) is used to quantify processing power in the Node B chipset. The number of
channel elements available for users is dependent on hardware configuration, and number of licensed channel
elements enabled. In general, channel elements for the common and overhead channels are included with the
Node B, and do not take from the pool of licensed channel elements. In the Ericsson Node B, channel elements
for uplink are located on the Random Access and Receiver (RAX) board. The total number of CE available is
dependent on the type of RAX board, as well as the number of RAX boards that are installed in the Node B. As
an example, the high capacity 3206 RBS can contain 8 RAX R2 boards with 128 channel element each, for a total
of 1024 channel elements. The channel elements for the downlink are located on the transmitter card. The total
number of CE available is dependent on the number of transmitter boards installed. The 3206 RBS can be
configured with 2 transmitter cards with 256 channel elements each, for a total of 512 channel elements.
The number of channel elements utilized by a UE is dependent on several factors. This includes the RAB type
used, as well as the soft/softer handover state of the UE. Table 5 provides some examples of downlink and
uplink CE usage based on RAB type. As the table shows, RABs with high data rates require additional processing
and therefore more channel elements. When a UE is in soft handover, the CE requirement obviously increases
since multiple Node Bs are involved. However, when a UE is in softer handover, the same CE will process the
multiple radio links within the same Node B.
Channel element allocation for EUL
Traffic on the HS-DSCH will not consume channel elements. However, every HSDPA connection will require A-DCHs for UL/DL
signaling and UL traffic. A-DCHs are dedicated channels, which consume channel elements. Dimensioning of DL resources for A-DCH
is not needed since DL A-DCHs do not consume resources from the normal pool of SW licensed channel elements. However,
resources for UL A-DCH have to be considered since they consume channels elements from the normal SW licensed pool.
Figure shows that if the R99 traffic load is low in the RBS the
EUL scheduler will have more channel elements to share
between the EUL users. The EUL users will thus have a
higher probability of being scheduled to high rates at low R99
traffic. If R99 traffic load increases, channel elements will be
removed from the EUL domain and EUL users will be
scheduled to lower rates.
The maximum number of channel elements that can be
allocated by E-DCHs can not be higher than the EUL license,
even if there are channel elements available in the SW
licensed pool.
OVSF and CE
Consumption for DL DCH
service
OVSF and CE
Consumption for UL DCH
service
OVSF and CE
Consumption for HSUPA
OVSF Code Usage
CE (Channel Element)
Congestion in CE (Channel Element) in Uplink is called Uplink CE Congestion. In 3G network mostly CE
congestion observed in Uplink Direction.
Lack of channel elements could be due to insufficient UL (RAX board) or DL (TX board) hardware capacity.
Channel element capacity could be also software limited. Admission control is restricted by ulHwAdm and
dlHwAdm parameters. They should be set at 100% so no hardware is limited for RRC/RAB setup.
The INVL command help us to see the CE
Congestion at RAX or TX could be indicated by
RBS counters pmUlCredits and pmDlCredits
respectively.
CE Congestion Causes and Solutions
Causes:
•
•
•
•
Shortage of License.
Neighbor site down
Overshooting
High number of AC block events on LackDlHw would indicate issues
with TX board and LackUlHw would indicate issues with RAX board.
Congestion at RAX or TX could be indicated by RBS counters
pmUlCredits and pmDlCredits respectively. Congestion per spreading
factor (SF) can be also measured using pmSetupFailureSfXX RBS
counters from the BasebandPool (BBP) on the uplink (UL BBP) and
the downlink (DL BBP).
Solutions for CE Congestion:
•
•
•
•
•
•
•
•
Upgrade the CE license according to your vendor.
R99 services uses more CE so try to reduce R99 services.
There are several parameters which can help R99 Service
utilization optimization.
Load Balancing between 2G and 3G or 3G and 4G can also
help to reduce Uplink CE Congestion.
Decrease the Max Bit Rate
Reduce Initial bit Rate from 64 to 32kbs
Enable the DCCC Algorithm
Check that ulHwAdm and dlHwAdm parameters are set to 100%
Check numHsResources, numEulResources at the node B (long term
solution) Reduce value of sf8Adm to 0 (short term solution) Check for
hardware failures on RAX and TXB boards and given the case, order
its replacement. Order an additional new RAX or TXB board,
depending on the specific case.
Reduce the eulServingCellUsersAdmTti2 value.
Low soft handover success rate due to UL HW congestion
The SHO handover success rate in a RNC degraded
mainly due to a site encounter the UL HW
congestion. But it has been taken care of after UL
CE license upgrade.
ASE (Air-interface Speech Equivalent)
ASE of a radio link = relative value, defined as the
air interface load relative to a speech radio link
(12.2kbps, 50% activity). A radio link with an ASE
of 3 in DL, is expected to generate as much
interference in downlink as 3 speech radio links
in the cell. General method of estimating ASE
value for a specific service
Code Tree Consumption
Lack of Canalization Code (pmNoFailedRabEstAttemptLackDlChnlCode)
Note: The code tree consumption
is measured in percentage of the
total tree size by excluding the
fixed codes allocated for HSDPA
(i.e. the higher the number of
codes allocated for HSDPA the
smaller will be the available tree
and
higher
the
relative
consumption).
The admission limit is set by
dlCodeAdm (as a percentage).
Logs Handling
RNCSM02> h lg
*******************************************************
lg[aevsyuoldhmircfx] [-l <logdirectory|logfile>] [-m <minustime>] [-p <plustime>] [-s <startdate>] [-e <enddate>]
[|<unixcmds>]
*******************************************************
Fetching and/or processing of node logs (alarm, event, availability, system, etc)
Options:
********
- a: parse alarm log (CELLO_ALARM_LOG.xml)
- e: parse event log (CELLO_EVENT_LOG.xml)
- v: parse availability log (CELLO_AVAILABILITY_LOG.xml)
- s: parse system log (/c/logfiles/systemlog/xxxsyslog)
- u: parse upgrade log (Trace.log and Trace.log_old)
- o: parse command log (CORBA_AUDITTRAIL_LOG.xml)
- y: parse securityevent log (CELLO_SECURITYEVENT_LOG.xml).
- l: parse coli log (SHELL_AUDITTRAIL_LOG.xml).
- h: parse hili log (CELLO_HWINVENTORY_LOG.xml). This file must first be generated with the command "hili mk".
- d: show node restarts and system downtime, based upon info of the system log and availability log.
- x: show alarms active on a specific date/time, based upon info of the alarm log.
- m: merge the different logs together (eg: lgaevm will merge alarm/event/availability logs). Not supported with "h"
option.
- i: inverse chronological order.
- r: refetch the logs from the node.
- c: print the output in csv format (semicolon separation).
- f: fetch the logs only and store them in a directory on the workstation.
Handover
Types of WCDMA Handover and Overall
Process
Initiation
There can be various types of WCDMA handover
as follows:
•
•
•
•
•
Soft & Softer handover
3G-2G IRAT handover
2G-3G IRAT handover
Inter Frequency handover
Load sharing
UE Measurements / Evaluation




Measurements
Filtering, Offsetting, Weighting
Evaluation
Reporting
RNC Evaluation
Execution
WCDMA RAN HO Entities
•
•
•
•
•
Soft/Softer Handover Execution (SHO_Eval)
Inter-Frequency Handover Execution (IFHO_Eval)
Inter-RAT Handover Execution (IRATHO_Eval)
Inter-RAT Cell Change Execution (IRATCC_Eval)
CN-HHO Execution (CN-HHO_Eval = Hard Handover via Core
Network evaluation algorithm)
• HS-DSCH Cell Change Execution (HSCC_Eval = Serving HS-DSCH
[High Speed Downlink Shared Channel] Cell Change evaluation
algorithm)
Entities Involved in Reporting, Evaluation, and
Execution of Handover-Related Functions
Soft/Softer Handover, Inter-Frequency Handover,
Inter-RAT Handover (including the particular case of
Service Based Handover), Inter-RAT Cell Change,
Hard Handover via Core Network, and serving HSDSCH Cell Change all consist of an evaluation part
and an execution part. The evaluation part initiates
and evaluates UE measurements on neighbor cells.
The execution part, triggered by the evaluation
results, allocates resources (if necessary) and
performs the actual Handover (including serving
HS-DSCH Cell Change) or Inter-RAT Cell Change.
UEs are configured to evaluate and send
measurement reports to the system only when
certain events occur.
UE Associated Cell sets for Measurement
• Active Set The cells involved in soft handover and measured by the
UE
• Virtual Active Set The Active Set associated with a non-used
frequency for support of Inter-Frequency evaluation
• Monitored Set The cells only measured by the UE and not part of
the Active Set. The monitored set can consist of intra-frequency,
Inter-Frequency and Inter-RAT cells or list of (neighboring) cells
whose pilot channel Ec/Io is continuously measured but not strong
enough to be added to the active set.
• Detected Set The intra frequency cells (P-CPICH scrambling codes)
detected by the UE and they are not in relation definition.
Monitored Set Creation
• After the UE has entered state CELL_DCH or after the Active
Set is updated (including successful IFHO), the Monitored Set is
created. It is based on the neighbor cells of the cells in the
Active Set and is typically updated when the Active Set is
updated.
• The Monitored Set consists of three subsets namely
– IAF Monitored Subset
– IEF Monitored Subset
– GSM Monitored Subset
Measurement Handling (Meas_Handl)
• The Measurement Handling algorithm prepares a list of cells that
the UE will measure on. The algorithm prepares a message to send
to the UE containing the measurement criteria, as well as the list of
cells to measure on, in accordance with the handover parameters
defined by the operator and the cells currently used in the active
set
– The number of Intra-frequency cells in the Monitored Set + the Active Set
cells is limited by 3GPP to 32.
– The number of Inter-Frequency cells in the Monitored set is limited to 32.
– The number of Inter-RAT cells in the Monitored set is limited to 32.
Overview of Sets and Subsets of Cells
Soft HO Vs. Softer HO
For soft handover
DL: For soft handover the situation is very similar in the downlink
direction. In the mobile station the signals received from the two different
base stations are combined using
UL: The received signals can no longer be combined in the base station
but are routed to the RNC. The combining follows a different principle; in
the RNC the two signals are compared on a frame-by-frame basis and the
best candidate is selected after each interleaving period.
For softer handover
Both in the DL and UL received signal can be combined in the same Rake
receiver, hence MRC (maximum Ratio Combining) can be used in both
direction
Soft & Softer handover
In Soft Handover the UE is connected to more than one RBS simultaneously. Soft Handover is possible and
necessary with a frequency re-use of one. At least one radio link is always active and there is no
interruption in the dataflow during the actual handover. The signals are received in the UE and combined
in the RAKE receiver to give protection against fading.
In Softer Handover the UE communicates with one RBS through several radio links. The Softer Handover
is a handover between two or more cells of the same RBS.
In addition to this code limiting effect described above,
soft and softer handover also add to the consumption of
OVSF codes. Assuming that the average soft handover
factor was 1.8 radio links per user, each user would
require 1.8 codes on an average (excluding the HSPDSCH).
In Soft Handover the combining techniques of information from different radio paths are different for
uplink and downlink.
In the uplink selective combining is used; the RNC receives transport blocks from different RBSs and
chooses the best block according to the CRC.
In the downlink the signals are combined in the Rake receiver in the UE, using MRC
(Maximum Ratio Combing).
In Softer Handover different diversity branches, both in the uplink and downlink, can be combined in the
same Rake receiver, hence MRC can be used in both directions.
Handover Events
To enable handovers, the UE is measuring on CPICHs in the active and monitored set, using the searcher finger of the Rake
receiver, When a new pilot enters the reporting range an event is triggered. Then the UE sends a report to the RNC for evaluation.
When new resources are needed the Soft/Softer Handover Execution checks with Admission Control if they are available, before
execution. The UE gets a message to add/replace or remove the new cell and information about the updated monitored set.
RNC
RNC
UE
UE
MEASUREMENT CONTROL message
(BCCH, DCCH)
MEASUREMENT REPORT message
RNC
RNC Evaluation
Evaluation
Perform
Perform
Measurement
Measurement
UE
UE Evaluation
Evaluation
(DCCH)
Execution
Radio
Radio Link
Link Addition
Addition
ACTIVE SET UPDATE
(DCCH)
ACTIVE SET
Radio
Radio Link
Link Removal
Removal
Radio
Radio Link
Link
Add/Remove/Replace
Add/Remove/Replace
UPDATE COMPLETE
RNC
RNC Evaluation
Evaluation
MEASUREMENT CONTROL message
(DCCH)
UeMeasControl
measQuantity1
enumRef:SupportedMeasQuantities
---------------------------------------------------------------------------------------------Used by UE functions for intra-frequency measurements (in CELL_DCH).
Quantity to measure for the chosen mode. The value of this attribute will set
the message data CPICH_Ec/No or CPICH_RSCP accordingly.
Dependencies: If CN Hard Handover is supported and measQuantity1 is
changed, (the measurement method is changed), the attribute
intraFreqCnhhoPenalty in MO Handover must be correctly set for the new
measurement method. The system will not enforce this.
Change takes effect: Ongoing connections (next switch to CELL_DCH)
Default=CPICH_EC_NO
Range: 1,2
Event-1a-Addition of a RL
When a primary CPICH, not included in the Active Set, enters the reporting range, event 1a occurs. The UE
sends an event 1a report to the RNC. If the reported cell is a valid neighbor and the Active Set is not full, the
cell is proposed as an addition to the Active Set. The event 1a reporting is configurable through the
parameter reportingRange1a.
> (reportingRange1a + hysteresis1a/2) for timetotrigger1a duration
Hysteresis1a = 0 = No Hysteresis
Reportingrange1a= 6 = 3 dB
Timetotrigger1a = 9 = 200ms
Event-1b-Removal of a RL
When a primary CPICH, included in the Active Set, leaves the reporting range, event 1b occurs. The UE
sends an event 1b report (proposal of Radio Link removal) to the RNC.
If the report includes more than one cell, all cells are proposed by the evaluation to be removed. However,
one cell is always kept in the Active Set. The event 1b reporting is configurable through the parameter
reportingRange1b.
< (reportingRange1b - hysteresis1b /2) for timetotrigger1b duration
Hysteresis1b = 0 = No Hysteresis
Reportingrange1b= 12 = 6 dB
Timetotrigger1b = 13 = 1280ms
Event-1c-Replacement of a RL
When a primary CPICH, not included in the Active Set, becomes stronger than the weakest CPICH in the
Active Set, event 1c occurs. The UE sends an event 1c report to the RNC.
If the reported cell is a valid neighbor and the Active Set is full, the reported cell is proposed as a
replacement for the weakest cell in the Active Set. The event 1c reporting is configurable through the
parameter hysteresis1c
Hysteresis1c = 2 = 1 dB
Timetotrigger1c = 11 = 320ms
Event-1d-Change of best cell in AS
When any of the primary CPICHs become stronger than the best primary CPICH, event 1d occurs. The UE
sends an event 1d report to the RNC.
the reported cell is a valid neighbor and the Active Set is not full, the cell is proposed as an addition to the
Active Set. If the Active Set is full, the cell is proposed as a replacement for the weakest cell in the Active
Set.
The event 1d reporting is configurable through the parameter hysteresis1d.
Hysteresis1d = 15 = 7.5 dB
Timetotrigger1d = 12 = 640ms
Counters & KPIs related to SHO
pmRlAddAttemptsBestCellSpeech : CS Speech RABs
pmRlAddAttemptsBestCellCsConvers : CS Conversational 64kbps RABs
pmRlAddAttemptsBestCellPacketHigh : high-rate (greater than 64 kbps) PS Interactive RABs
pmRlAddAttemptsBestCellPacketLow : low –rate (less than 64 kbps) PS Interactive RABs
pmRlAddAttemptsBestCellStandAlone : Stand-alone SRB 13.6 connections
pmNoTimesCellFailAddToActSet : Number of times that a cell could not be added to the active set of a UE.
pmSumUesWith1Rls1RlInActSet : Sum of all sample values recorded during a ROP for the number of UEs
with one radio link set and one radio link in the active set.
pmSumUesWith1Rls2RlInActSet
pmSumUesWith1Rls3RlInActSet
SHOSuccess = 100 * pmNoTimesRlAddToActSet / (pmNoTimesRlAddToActSet +
pmNoTimesCellFailAddToActSet) Accepted range is 99
SHO Overhead = (1* pmSumUesWith1Rls1RlInActSet +2* pmSumUesWith1Rls2RlInActSet +3*
pmSumUesWith1Rls3RlInActSet )/(pmSumUesWith1Rls1RlInActSet + pmSumUesWith2Rls1RlInActSet +
pmSumUesWith3Rls1RlInActSet)
Accepted range is 1.5
Inter Frequency & Inter RAT Handover
Inter-Frequency handover is only attempted if IfHoAllowed is set to Allowed and FddIfHoSupp is set to On for the
current UeRc state.
Inter-RAT handover is only attempted if GsmHoAllowed is set to Allowed and FddGsmHoSupp is set to On for the
current UeRc state.
If both Inter-Frequency handover and Inter-RAT handover are allowed and both Inter-Frequency and Inter-RAT
neighbors cells exist for the cells in the Active Set, the decision to perform Inter-Frequency or Inter-RAT handover
is based on a configurable parameter, hoType, defined per cell
The Inter-frequency or IRAT handover is triggered based on three criteria, Ec/No, RSCP) and UE Tx Power. These
events are also used for IRATHO and IRATCC. Based on that Event 2d,2b,2f,3a will occur.
What is compressed mode?
During inter-frequency handover the UE’s must be given time to make the necessary measurements on the
different WCDMA carrier frequency. 1 to 7 slots per frame can be allocated for the UE to perform this intra
frequency (hard handover). These slots can either be in the middle of the single frame or spread over two frames.
This compressed mode operation can be achieved in three different methods:
•
•
•
Decreasing the spreading factor by 2:1. This will increase the data rate so bits will get sent twice as fast.
Puncturing bits. This will remove various bits from the original data and hence reduce the amount of
information that needs to be transmitted.
The higher layer scheduling could also be changed to use less timeslots for user traffic
Inter Frequency Handover-Event 2d,2b,2f
Ran quality of current frequency < (usedFreqThresh2dEcno + serviceOffset2dEcno-hysteresis2d/2) for a duration
timetotrigge2d—Event 2d triggers and UE enters the compressed mode.
Ran quality of current frequency > (usedFreqThresh2dEcno + serviceOffset2dEcnohysteresis2d/2+usedFreqRelThresh2fEcno) for a duration timetotrigge2f—Event 2f triggers and UE exists the
compressed mode.
Inter Frequency Handover-Event 6d, 6
The UE is also configured for event trigger decision based on threshold ueTxPowerThresh6b Reporting event 6d and 6b
If the UE TX Power reaches maximum, and the condition is maintained during a time not less than timeTrigg6d, then
event 6d occurs and Inter-Frequency or GSM/GPRS measurements need to be performed by UE. If the UE TX Power
goes below ueTxPowerThresh6b threshold, and the condition is maintained during a time not less than timeTrigg6b,
then event 6b occurs and the UE is requested to stop measurements on Inter-Frequency GSM/GPRS cells.
Inter Frequency Handover-Sequence
If the measured quality of the best cell in the Active Set on the currently used frequency is below usedFreqTresh2dEcno +
usedFreqThresh4_2bEcno, and the quality and RSCP of the measured best cell on unused frequency both are above
nonusedFreqThresh4_2bEcno and nonusedFreqThresh4_2bRscp (also taking the hyst4_2b into account), the UE sends a
measurement report after timeTrigg4_2b to the SRNC to perform the handover.
Inter Frequency
parameters
usedFreqThresh2dRscp = -102 (Cell Level)
usedFreqThresh2dEcno = -13 (Cell Level)
Hysteresis2d=0
Hysteresis2f =0
nonUsedFreqThresh4_2bRscp= -95
nonUsedFreqThresh4_2bEcno= -10
timeToTrigger2dEcno=320
timeToTrigger2dRscp=320
timeToTrigger2fEcno=1280
timeToTrigger2fEcno=1280
timeToTrigger6d=320
timeTrigg4_2b=100
timeTrigg6b=1280
ueTxPowerThresh6b=20
usedFreqRelThresh2fEcno=2
usedFreqRelThresh2fRscp=3
usedFreqRelThresh4_2bEcno=-1
usedFreqRelThresh4_2bRscp=-3
IRAT parameters
usedFreqThresh2dRscp = -102 (Cell Level)
usedFreqThresh2dEcno = -13 (Cell Level)
Hysteresis2d=0
Hysteresis2f =0
timeToTrigger2dEcno=320
timeToTrigger2dRscp=320
timeToTrigger2fEcno=1280
timeToTrigger2fEcno=1280
timeToTrigger6d=320
usedFreqRelThresh2fEcno=2
usedFreqRelThresh2fRscp=3
Hysteresis3a=0
timeToTrigger3a=6
utranRelThresh3aEcno=0
utranRelThresh3aRscp=-5
measQuantity1= 2 (CPICH_EC_NO)
Inter RAT Handover-Event 2d,3a,2f
Ran quality of current frequency < (usedFreqThresh2dEcno + serviceOffset2dEcno-hysteresis2d/2) for a duration
timetotrigge2d—Event 2d triggers and UE enters the compressed mode.
Ran quality of current frequency > (usedFreqThresh2dEcno +
serviceOffset2dEcno+hysteresis2d/2+usedFreqRelThresh2fEcno) for a duration timetotrigge2f—Event 2f triggers and
UE exists the compressed mode.
Inter RAT Handover-Event 2d,3a,2f
estimated quality of the currently used radio link < usedFreqTresh2dEcno - utranRelThresh3aEcno – Hysteresis3a/2
estimated quality of the target GSM cell > gsmThresh3a+Hysteresis3a/2 for a time duration timetotrigger3a
Inter RAT Cell ChangeEvent 2d,3a,2f
Inter RAT HandoverEvent 2d,3a,2f
Inter Handover 2G-3G
Triggering will be based on QSC settings when to start WCDMA measurements. The 2G-3G neighbor list has
to be defined for every cell in BSC which will be broadcasted on the SACCH. This list can be the same as the
list broadcast on BCCH to Multi-RAT MSs in idle mode, but it is also possible to set it separately in order to
have different UMTS neighbors in idle and active mode.
The Multi-RAT mobile is informed of how many UMTS cells (0-3) shall be reported in the measurement
report. This is set by parameter FDDMRR. The remaining positions will be used for GSM cells.
2 criteria's must be full filled for a GSM
to UMTS handover to happen.
• Percentage of idle TCH in the
serving cell ≤ ISHOLEV
• CPICH Ec/No > MRSL
WCDMA Load Sharing Techniques
 Load sharing enhances the performance of a Radio
Access Network by pooling together resources from
different parts of the entire network.
 The following load-sharing features are available in the
WCDMA RAN:
Inter-Frequency Load Sharing
HS IFLS non HS IFLS
Directed Retry to GSM
Load based HO to GSM
Inter-frequency load based HO
Service based HO
Inter-Frequency Load Sharing-Configuration
 This feature is activated in an RNC by setting the parameter loadSharingRrcEnabled to TRUE.
 The attribute loadSharingCandidate specifies whether the target cell is a load-sharing neighbor of the
source cell.
 Possible values for loadSharingCandidate are TRUE and FALSE.
 There should be no more than one neighbor per carrier for each source cell, and all load-sharing neighbors
should be co-located.
 This feature uses the same neighbor-cell relations as Inter-Frequency Handover.
 If a relation is created for Load Sharing purpose but not wanted by Inter-Frequency Handover, the
handover can be suppressed by setting the cell parameter hoType to NONE or GSM_PREFERRED.
Inter-Frequency Load Sharing-Operation
 The amount of resource excluded from load-sharing use is specified by the
cell parameter loadSharingMargin as a percentage of pwrAdm.
 The performance of Inter-Frequency Load Sharing can be monitored via the
following three counters:
• pmTotNoRrcConnectReq gives the total number of RRC connection
requests in a cell.
• pmNoLoadSharingRrcConn gives the number of RRC redirections
performed for load-sharing reason in a cell.
• pmNoOfReturningRrcConn gives the number of calls that has returned
to the original frequency after an RRC-redirection.
HS/Non HS IFLS
•
IFLS feature will help to sending exceedig traffic in a cell to other carriers in order to balance the number of users and
avoid congestion. This feature works for HS and Non HS IFLS when activated at RNC level:
–
–
•
rncfeature hspaloadsharing  TRUE (HS IFLS at RNC level)
rncfeature dchloadsharing  TRUE (Non HS IFLS at RNC level)
In order to use this feature is necessary to create for each cell a coverage relation with all other carriers of the same
sector. Next step is configure and activate the feature at coverage relation level:
–
–
set UtranCell=WXXX,CoverageRelation=WXXX relationCapability dchLoadSharing=1
set UtranCell=WXXX,CoverageRelation=WXXX relationCapability hsLoadSharing =1
› The following initial configuration was used:
–
–
–
–
–
–
hsPathlossThreshold  120 (coverage relation level) (Pathloss threshold used for both HS IFLS)
pathlossThreshold  170 (sector level) (A pathloss check is performed before triggering a blind IFHO to a candidate cell, when
performing load sharing from DCH state. If the pathloss is high
er than this threshold, the blind IFHO is not allowed.)
hsIflsMarginUsers  10 (sector level) (Margin for HS interfrequency load sharing, relative to the admission limit hsdpaUsersAdm)
hsIflsThreshUsers  20 (sector level) (load sharing triggered for source cell)
dchIflsThreshPower -> 0 (power threshold for DCH load sharing)
IFLS
(inter Frequencies Load Sharing)
UtranCell
hsIflsThreshUsers
long
-----------------------------------------------------------------------------------------------------------------------------------Threshold for triggering HS interfrequency load sharing in the source cell, relative to the admission limit hsdpaUsersAdm. If more than hsIflsThreshUsers/100 * hsdpaUsersAdm HS users are present when a RAB transition is
being evaluated, load sharing is triggered.
Setting this parameter to 0 disables HS interfrequency load sharing in this cell.
Only used if RncFeature=HspaLoadSharing or RncFeature=IflsRedirectDownswitch (or both) is activated.
Feature: HspaLoadSharing, IflsRedirectDownswitch
Change takes effect: Immediately
Unit: %
Range: 0 to 100, Default=0
UtranCell
hsIflsMarginUsers
long
-----------------------------------------------------------------------------------------------------------------------------------Margin for HS interfrequency load sharing, relative to the admission limit hsdpaUsersAdm. When calculating remaining free resources in the cell during evaluation of a RAB transition, this margin is subtracted from the result,
making the cell look more loaded than it is and therefore making it a less likely target for HS inter-frequency load sharing decisions.
Only used if RncFeature=HspaLoadSharing or RncFeature=IflsRedirectDownswitch (or both) is activated.
Feature: HspaLoadSharing, IflsRedirectDownswitch
Change takes effect: Immediately
CPICH Ecno Thr & iflsMode
•
The parameter iflsCpichEcnoThresh defines the measured downlink EcNo value above which
HS and Non HS IFLS reconfiguration from FACH or URA are allowed. When configured as -24
means that this value is not used and reconfigurations are always allowed when HS and/or
Non HS IFLS are activated.
•
iflsMode defines the RAB reconfigurations that can trigger and IFLS event. This can be due to:
–
–
–
•
RAB Establishment (0)
Upswitch attemps (1)
Both (2)
In our network we are usingfollowing configuration:
–
–
iflsCpichEcnoThresh  -24
iflsMode  2 (RAB Establishment and Upswitch attempts)
HS Pathloss Threshold
•
IFLS feature works by means of Blind Handover that is, is not performing measurements
before sending the traffic to other carriers as a common Handover would made. For this
reason is commonly seen RAB issues affecting the PS accessibility performance due to big
difference in coverages.
•
A tuning of the parameter hsPathlossThreshold will help to improve the chances of success by
doing a check between the source and target before launch a blind handover. If the pathloss is
higher that threshold the IFLS is not allowed. For tis case we use the configuration:
–
–
hsPathlossThreshold  115 (for 850 carrier)
hsPathlossThreshold  120 (for 2100 carrier)
IFLS at downswitch
•
This feature offers the possibility to redirect the User Equipments to another carrier, this
triggered by in-activity downswitches from DCH to FACH or URA states or fastDormancy.
•
This feature only should be activated if the feature IflsRedirectDownswitch is active on the
RNC.
•
For this case, the configuration selected was only from DCH to FACH.
•
•
•
•
•
•
•
•
•
get utrancell=”XXX” hsiflsdownswitchtrigg
======================================================================
MO
Attribute
Value
======================================================================
UtranCell=”XXX”
hsIflsDownswitchTrigg Struct{3}
>>> 1.toFach = 1 (ON)
>>> 2.toUra = 0 (OFF)
>>> 3.fastDormancy = 0 (OFF)
Directed Retry To GSM


If a call is chosen for Directed Retry to GSM, the request for the speech RAB will be rejected
with cause “Directed retry” and then a request is made to the core network to relocate the UE
to a specific GSM cell, using the Inter-RAT handover procedure .
The target cell must be co-located with the WCDMA cell.
Directed Retry to GSM
Directed Retry to GSM Traffic Case
Directed Retry to GSM-Configuration
 Directed Retry to GSM is activated in an RNC by setting
the flag loadSharingDirRetryEnabled to TRUE.
 One GSM target can be defined for each WCDMA cell via
the cell parameter directedRetryTarget.
 It must be ensured that the correct GSM targets have
been defined and that they are indeed co-located with
their respective source cells in the WCDMA RAN.
Directed Retry to GSM-Operation
 There are two parameters for this feature:
•
loadSharingGsmThreshold specifies the minimum cell load at which offloading to GSM starts.
•
A value of 0 means the feature is always on, 100 means it is always off, and
50 means off-loading starts as soon as the cell load rises above 50% of the
admission limit.
 loadSharingGsmFraction specifies the percentage of Directed Retry
candidates to be diverted to GSM while the cell load is above the specified
load threshold.
•
A value of 0 means no diversion will take place and a value of 100 means all
calls qualified for Directed Retry will be diverted.
 The success rate can be monitored by two counters and they are:
• pmNoDirRetryAtt gives the total number of Directed Retry attempts.
• pmNoDirRetrySuccess gives the number of successful attempts.
Load based HO to GSM
 This feature enables HO to GSM for speech calls, when the load is
high in a WCDMA cells.
 Following different load quantities are used to trigger this functionality• DL power load.(>PwrAdm)
• DL Code tree load (>DlCodeAdm)
• UL or DL RBS HW load. (UlHwAdm/DlHwAdm)
• UL or DL ASE load. (UlAseAdm/DlAseAdm)
 If high load is detected for one or several of theses load quantities,
speech-only users can be selected for GSM HO attempts.
 The UEs are instructed to perform measurements for GSM cells , and
HO attempts can be triggered if the UEs detect and report a good
enough GSM cell.
Load based HO to GSM-Configuration
 This feature will use the Admission control functionality as a way to
detect high load in a WCDMA cell.
 loadbasedHoSupport is set to True and lbhoType is set to
lbho_GSM in the cell.
 lbhoMinSpeechUsers can be set so that a number of speech users
are allowed to remain in the cell before the loadbased HO is
activated.
 lbhoMinTriggerTime is a timer which can be set to slow down the
loadbased HO functionality, so that the loadbased HO attempts
happen more seldom.
 lbhoMaxTriggeredUsers is used to define the maximum number of
HO triggered simultaneously.
Load based HO to GSM-Operation
 To perform GSM HO number of conditions are checked and they are as
follows:
• CS speech only user, and it is not an Emergency call.
• Compressed mode and other HO attempts not already ongoing for the
user.
• Service handover IE not equal to "Shall not".
• fddGsmHoSupport is ON.
• The connection is not originating from another RNC over Iur.
 The total number of compressed mode users in a cell is limited by the
parameter compModeAdm, and if many Load based HO attempts are
initiated, the number of coverage triggered HO attempts might be limited.
•
The counter “pmSumCompMode” together with “pmSamplesCompMode”
are used to monitor the number of radio links in compressed mode per
UtranCell before and after the feature is activated.
Load based HO to GSM-Configuration
Cedr command :
Inter-frequency load based HO
 This feature enables Inter-frequency HO for speech calls, when the
load is high in a WCDMA cell.
 The intention is to be able to offload the WCDMA network to another
external WCDMA network.
 For utilize this feature the network uses Core Network Hard
Handover, but it is also possible to offload to IF cells within the same
RNS.
 The load quantities and general functionality are the same as for
Load based HO to GSM.
 For defining IF HO IF neighbours are used.
Inter-frequency load based HO-Configuration
 This feature will use the Admission control functionality as a way to detect
high load in a WCDMA cell.
 loadbasedHoSupport is set to True and lbhoType is set to lbho_IF in the
cell.
 lbhoMinSpeechUsers can be set so that a number of speech users are
allowed to remain in the cell before the loadbased HO is activated.
 lbhoMinTriggerTime is a timer which can be set to slow down the loadbased
HO functionality, so that the loadbased HO attempts happen more seldom.
 The threshold nonUsedFreqThresh4_2bEcn0 + serviceOffset2dEcno is
used for the IF quality as for normal IFHO, the value 0 is used for the
WCDMA quality.
Inter-frequency load based HO-Operation
 In order to support different network configurations and scenarios, the
creation of the IF monitored set is filtered when triggered by IF LBHO.
 The value of parameter ifLbhoMode is as follows:
• ifLbhoMode = 1 Include all defined IF neighbour cells.
• ifLbhoMode = 2 Include only “Non-Iur external” IF cells used for CNHHO.
• ifLbhoMode = 3 Do not include “Non-Iur external” IF cells used for
CNHHO.
 The counter “pmSumCompMode” together with “pmSamplesCompMode”
can be used to monitor the number of radio links in compressed mode per
UtranCell before and after the feature is activated.
SBHO Feature description
• The feature Service Based Handover makes it possible to restrict or promote Inter RAT Handover (Inter
System Handover) based on IMSI and Call Type. The process is trigged by the assignment procedures.
• By using this feature subscribers can be directed (via Inter RAT Handover) to a preferred access network
(GSM or WCDMA) based on the type of service requested.
• The Service Based initiated IRAT handover is executed as a “normal” IRAT handover after that
measurement has been made on the neighbouring GSM / WCDMA cells (the measurements takes
normally about 5-10 seconds).
So, Service Based Handover is not a “blind” handover.
SBHO –Service Indicators(SI)
• Should: The system should immediately initiate required actions, e.g.
compressed mode measurements to determine the correct target cell, in
order to perform an inter-RAT transfer of the connection to GSM as soon as
possible.
• Should Not: Neither Compressed Mode for GSM measurement, nor
connection transfer to GSM shall be initiated, unless the quality/strength
requires an inter-RAT transfer in order to save the connection.
• Shall Not: Neither Compressed Mode for GSM measurements, nor
connection transfer to GSM shall be initiated, regardless of any radio
related reason to perform such actions.
• Missing value: The system shall initiate required actions, e.g. compressed
mode measurements to determine the correct target cell, when this is
required for radio network reasons, e.g. bad signal quality.
SBHO –Service Indicators(SI)
HSDPA cell change
3 licensed features to be activated for HSDPA/Eul cell change.
HSPA Cell change between HSPA capable cells:
A moving UE with an HSPA ongoing call will attempt
to perform a cell change each time an event 1d HS,
1b or 1c is triggered. The call is maintained on HSPA
if the target cell is HSPA capable and is not rejected
by admission control.
hsTimeToTrigger1d : 640
hsQualityEstimate : 1 (CPICH_RSCP)
HSPA cell change to non-HSPA capable cell : If the HSPA UE is trying to
perform cell change to a non-HSPA cell the call can be steered to DCH.
The parameter hsToDchTrigger can be used to enable the transition
from HS-DSCH to DCH
hsOnlyBestCell : FALSE
Eul cell change
When one UE with an active EUL connection moves towards a cell that is not EUL capable, the new cell is not
added to the active set. Instead, the RNC keeps count of add and replace events reported from the UE and in
which the RSCP or Ec/N0 level is greater than that in the serving cell by event1dRncOffset dB
When the number of events exceeds a threshold event1dRncThreshold dB, the connection is reconfigured to
DCH/HSDPA.
Exactly the same happens if EUL 2 ms TTI is used and the candidate cell is only supporting 10 ms TTI. In this case
the UE will be down switched to R99, from where it may perform channel switching to EUL 10 ms TTI.
Initiation
• Event Based triggering where UE is involved in the decision.
• Evaluation and reporting can be based on CPICH Ec/No or
CPICH RSCP.
– SHO , CNHHO : CPICH Ec/No is default
– HSCC Evaluation : CPICH RSCP is default
• For IRAT HO and IFHO, UE Tx (UL) power can also be taken as
an input
Measurements
•From the Ue perspective all the cells are divided into one of these subsets
according to 3GPP
– Active Set (AS): The cells involved in soft handover and measured by the UE
– Monitored Set (MN):
• The monitored set is created from the neighbor cell lists of all the cells in the
Active Set
• The max number of cells in each set is 32.
– Unmonitored set: cells excluded from MN set because MN set is full. UE is not
ordered to measure them.
– Detected Set (DN) : The intra frequency cells detected by the UE but not part of
Active Set or monitored set. (Can then be an Unmonitored or a Missing neighbor)
UMTS Handover Events
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Event 1A: A Primary CPICH enters the reporting range; addition of a radio link.
Event 1B: A primary CPICH leaves the reporting range; removal of a radio link.
Event 1C: A non-active primary CPICH becomes better than an active primary CPICH; replacement of the worst cell in AS.
Event 1D: Change of best cell.
Event 1E: A Primary CPICH becomes better than an absolute threshold
Event 1F: A Primary CPICH becomes worse than an absolute threshold
Event 1G: Change of best cell (TDD)
Event 1H: Timeslot ISCP below a certain threshold (TDD)
Event 1I: Timeslot ISCP above a certain threshold (TDD)
Event 2A: Change of Best Frequency.
Event 2B: The estimated quality of the currently used frequency is below a certain threshold and the estimated quality of a non-used
frequency is above a certain threshold; handover to inter-frequency neighbors
Event 2C: The estimated quality of a non-used frequency is above a certain threshold.
Event 2D: The estimated quality of the currently used frequency is below a certain threshold ; start compressed mode to measure interfrequency WCDMA or GSM neighbors.
Event 2E: The estimated quality of a non-used frequency is below a certain threshold.
Event 2F: The estimated quality of the currently used frequency is above a certain threshold; stop compressed mode & stop measure
inter-frequency WCDMA or GSM neighbors
Event-triggered reporting
The User Equipment (UE) continuously monitors the radio
environment. Not only defined neighbor cells are measured,
but also cells that are undefined neighbors can be detected
with the background scanning process. The UE is configured to
evaluate and send measurement reports to the system only
when certain events occur, such as when the measurement
result for a cell fulfills certain criteria.
SHO Process
End result of the process
is one of the following
 Radio Link addition
 Radio Link removal
 Combined Radio Link
addition and Radio Link
removal
 New proposal rejection,
actual Active Set is maintained
 Connection is released
Measurement Control (which
contains the list of cells the UE has to
measure) might not be sent in case
there is no change in the Monitored set
from previous state.
Good Counters for HO
This issue occurs when the target cell in Hanover has problem for instance
• Transmission
• Capacity
• Channel Element limitation
At the first step, the relation must be check (pmRlAddAttemptsBestCellSpeech
and pmNoTimesCellFailAddToActSet)
And find the problematic neighbor.
If there is not any problematic neighbor the decrease of EUL admission threshold can
help us
pmRlAddAttemptsBestCellSpeech
Number of attempted radio link additions for calls that included any CS
Conversational Speech RAB (including AMR Single-mode 12.2, AMR-NB Multimode single- and multi-rate, and AMR-WB).
Condition: Incremented by one in the best cell in the active set when an
attempt is made to add a new RL to the active set or to replace an RL in the
active set, for a call that includes a CS Conversational Speech RAB.
The counter is incremented after a handover proposal from the handover
evaluation function or after the RNC receives an RNSAP Radio Link Addition
Request message.
pmNoTimesCellFailAddToActSet
Number of times that a cell could not be added to the active set of a UE.
Condition: Incremented by one in the target cell (the cell that could not be
added to the active set), when any of the following occurs during an attempt
to add an radio link:
- admission is not granted
- it is not possible to allocate a downlink channelization code
- the RNC receives an NBAP Radio Link Setup Failure message from the RBS,
indicating that the Radio Link Setup procedure failed
- the RNC receives an NBAP Radio Link Addition Failure message from the RBS,
indicating that the Radio Link Addition procedure failed
- the Radio Link Setup or Radio Link Addition procedure times out in the RBS
- the RNC receives an RRC Active Set Update Failure message from the UE,
indicating that the Active Set Update procedure failed
- the Active Set Update procedure times out in the UE
pmEnableHsHhoAttempt
Number of attempted hard handovers to an HS-DSCH cell, for which this cell was the best cell in the source active set (the active set when the transition was triggered).
Condition: Incremented by one in the best cell in the source active set, when a Physical Channel Reconfiguration message is sent to the UE for an attempted hard
hardover to an HS-DSCH cell that has a coverage relation to a cell in the active set, during Serving HS-DSCH Cell Selection. The best cell is the cell with the highest
measured quality as defined by UeMeasControl::hsQualityEstimate.
Counter type: PEG
Scanner: Not included in any predefined scanner
Counter is reset after measurement period: Yes
Counter context: SRNC, DRNC if IurLink::srncPmReporting = ON in SRNC
pmEnableHsHhoSuccess
Number of successful hard handovers to an HS-DSCH cell, for which this cell was the best cell in the target active set (the active set when the transition was concluded).
Condition: Incremented by one in the best cell in the target active set, when a Physical Channel Reconfiguration Complete message is received from the UE during an
attempted hard handover to an HS-DSCH cell that has a coverage relation to a cell in the active set, during Serving HS-DSCH Cell Selection. The best cell is the cell with the
highest measured quality as defined by UeMeasControl::hsQualityEstimate.
Counter type: PEG
Scanner: Not included in any predefined scanner
Counter is reset after measurement period: YesCounter context: SRNC, DRNC if IurLink::srncPmReporting = ON in SRNC
pmEnableEulHhoAttempt
Number of attempted hard handovers to an E-DCH cell, for which this cell was the best cell in the source active set (the active set when the transition was triggered).
Condition: Incremented by one in the best cell in the source active set, when a Physical Channel Reconfiguration message is sent to the UE for an attempted hard
hardover to an E-DCH cell that has a coverage relation to a cell in the active set, during Serving E-DCH/HS-DSCH Cell Selection. The best cell is the cell with the highest
measured quality as defined by UeMeasControl::hsQualityEstimate.
For Multi Carrier connections, this counter is incremented only if this cell is a serving HS-DSCH cell.
Counter type: PEG
Scanner: Not included in any predefined scanner
Counter is reset after measurement period: Yes
Counter context: SRNC, DRNC if IurLink::srncPmReporting = ON in SRNC
pmEnableEulHhoSuccess
Number of successful hard handovers to an E-DCH cell, for which this cell was the best cell in the target active set (the active set when the transition was concluded).
Condition: Incremented by one in the best cell in the target active set, when a Physical Channel Reconfiguration Complete message is received from the UE during an
attempted hard handover to an E-DCH cell that has a coverage relation to a cell in the active set, during Serving E-DCH/HS-DSCH Cell Selection. The best cell is the cell with
the highest measured quality as defined by UeMeasControl::hsQualityEstimate.
For Multi Carrier connections, this counter is incremented only if this cell is a serving HS-DSCH cell.
Counter type: PEG
Scanner: Not included in any predefined scanner
Counter is reset after measurement period: Yes
Counter context: SRNC, DRNC if IurLink::srncPmReporting = ON in SRNC
Soft HO
Soft HO Counters
pmNoTimesCellFailAddToActSet
Number of times that a cell could not be added to the active set of a UE. Condition: Incremented by one in the
target cell (the cell that could not be added to the active set), when any of the following occurs during an
attempt to add an radio link:
admission is not granted
it is not possible to allocate a downlink channelization code
the RNC receives an NBAP Radio Link Setup Failure message from the RBS, indicating that the Radio Link Setup procedure failed
the RNC receives an NBAP Radio Link Addition Failure message from the RBS, indicating that the Radio Link Addition procedure failed
the Radio Link Setup or Radio Link Addition procedure times out in the RBS
the RNC receives an RRC Active Set Update Failure message from the UE, indicating that the Active Set Update procedure failed
the Active Set Update procedure times out in the UE.
pmRlAddAttemptsBestCellSpeech
Number of attempted radio link additions for calls that included any CS Conversational Speech RAB (including AMR Single-mode
12.2, AMR-NB Multi-mode single- and multi-rate, and AMR-WB).
Condition: Incremented by one in the best cell in the active set when an attempt is made to add a new RL to the active set or to
replace an RL in the active set, for a call that includes a CS Conversational Speech RAB. The counter is incremented after a handover
proposal from the handover evaluation function or after the RNC receives an RNSAP Radio Link Addition Request message
IRAT_HO
Neighbor Edit
GSM relation Selection priority
Audit was done for one RNC
based on:
• 2G to 2G attempts
• The IRAT relation Audit
There are improvements in
Speech Drop Rate and IRAT
HO/CC Success rate both with
and without relocation
3G Neighbors (2G and 3G)
3G neighbor checking
in 2G
The 2G commands shows the cells
which are defined for 3G cell
cr RncFunction=1,UtranCell=7097XC1,utranrelation=7097XC1_7096XA1 utrancell=7096XA1
compressed mode
• It also known as the Slotted Mode, is needed when making
measurements on another frequency (inter-frequency) or on a
different radio technology (inter-RAT). In the Compressed Mode
the transmission and reception are stopped for a short time and
the measurements are performed on other frequency or RAT in
that time. After the time is over the transmission and reception
resumes. To make sure that the data is not lost, the data is
compressed in the frame making empty space where
measurements can be performed. 1 to 7 slots per frame can be
allocated for the UE to perform this intra frequency (hard
handover)
For one RNC , which had the highest
number of congested 2G cells which had
an active co-sited 3G cell, we have
changed the compress Mode triggering
thresholds for both RSCP and EcNo
which has resulted in increased speech
traffic retention on 3G and reduction in
IRAT per call for the RNC
Compressed Mode trigger (event 2D)
threshold for RSCP and EcNo were
relaxed from -95 to -102 and from -12 to
-13 respectively
Compressed Mode
Modifying the 2D parameters (Compressed
Mode trigger threshold )
2d thresholds were changed in one RNC on 23rd August. below shows the summary of the results:
 Speech traffic increased by almost 35%.
Parameter
usedFreqThresh2dEcno
 No visible impact on CSSR and Throughput.
usedFreqThresh2dRscp
 30% reduction in IRAT HO attempts.
 Speech drop rate significantly improved because of reduced number of IRAT-related drops.
Old
-12
-95
New
-13
-102
Find Worse Cell in RNC
For seeing Propagation Delay
• pmx . pmpropag
Date: 2015-07-25
Sector=1,Carrier=1,Prach=1 pmPropagationDelay 464,27836,7444,129,0,0,2,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
Sector=1,Carrier=2,Prach=1 pmPropagationDelay 464,32678,8963,46,0,0,0,0,0,0,0,29,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
Sector=3,Carrier=1,Prach=1 pmPropagationDelay 464,16388,3955,1,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
Sector=3,Carrier=2,Prach=1 pmPropagationDelay 464,19812,5413,13,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
Sector=4,Carrier=1,Prach=1 pmPropagationDelay 464,36250,767,10,16,0,5,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
• Another one (Has overshooting)
Sector=1,Carrier=1,Prach=1 pmPropagationDelay 464,6025,6359,3636,3577,295,325,27,86,47,63,9,20,48,23,11,64,4,132,0,2,0,6,2,1,3,12,9,8,6,0,0,0,0,0,0,0,0,0,0,0
Sector=1,Carrier=2,Prach=1 pmPropagationDelay
464,4500,16025,7645,5416,248,430,31,18,84,18,9,21,65,2,6,60,23,180,1,3,2,5,2,0,16,19,2,2,0,0,0,1,0,0,0,0,0,0,0,0
Sector=2,Carrier=1,Prach=1 pmPropagationDelay
464,2867,7607,6746,4605,3818,2922,1850,96,48,793,2441,77,2,2,0,1,1,0,0,0,0,0,2,0,0,0,0,0,0,0,0,0,0,0,1,0,0,0,0,0
Sector=2,Carrier=2,Prach=1 pmPropagationDelay
464,6499,12448,3527,4205,2455,1048,1654,153,161,820,1977,20,0,36,1,2,0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
Sector=3,Carrier=1,Prach=1 pmPropagationDelay
464,4349,3039,5249,4329,121,189,113,117,244,23,22,40,123,230,140,30,32,45,1,0,24,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
Sector=3,Carrier=2,Prach=1 pmPropagationDelay
464,2619,5857,2568,7619,218,219,385,149,26,31,29,6,72,239,48,26,46,28,0,17,6,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
For seeing type and configuration (Tilt) of antenna
The productNo. Command showe the type of RET, and also the Aretdevicedata showe the type of antenna which set for the specific RET
Change Tilt
Cell Power
With the following commands we can find the power license,
maximum power for cells and cell’s power
Command: set RbsSubrack=RUW1,RbsSlot=13,AuxPlugInUnit=RUW-1,DeviceGroup=RUW,TpaDeviceSet=1,TpaDevice=1
maxTotalOutputPower 80
For tracing NodeB implemented commands
Find Scrambling code
Power Expansion
1300
For cell expansion we have taken into
consideration:
•
1100
969
978
20150907
1000
900
800
700
675
672
600
583
586
20150831
610
625
626
20150902
634
20150901
700
20150830
The list can be prioritized into 3
categories
1) Cells with less than 500 Kbps
2) between 500 kbps and 800 kbps
3) greater than 800 kbps
1200
20150906
•
•
HS power Utilization (more than
90%),
HS Users (RABs),
And the user Throughput
1,216
597
500
20150908
20150905
20150904
20150903
20150829
20150828
20150827
Standardization of Primary CPICH
Power
1.
All cell with CPICH power below 320 were
analyzed for
a)
b)
c)
d)
2.
Power utilization,
Admission rejections,
Overshooting,
RET status.
CPICH power for these cells were increased in
steps of 1dB until:
a) They were increased to 320
b) They were limited by power utilization
c) They encountered the resource rejection
3.
4.
Impact of this activity on KPIs, Power utilization
, Compressed Mode and Throughput has been
shown in this slide
Some required changes must be implemented
for remaining cells.
a) Down tilt Required (RET not installed)
b) New site required
c) Power Expansion Required
d) UL CE Expansion required
Print CPICH power (get XXX primarycpich)
Print CPICH power (get XXX primarycpich)
High-Speed Shared Control Channel HS-SCCH And Its Work In 3G WCDMA
Carries physical layer signaling to a single UE, such as modulation scheme (1 bit), channelization code set (7 bit), transport block size (6bit), HARQ process number
(3bit), redundancy version (3bit), new data indicator (1bit), UE identity (16bit) HS-SCCH is a fixed rate (60 kbps, SF=128) downlink physical channel used to carry
downlink signaling related to HS-DSCH transmission
HS-SCCH High-Speed Shared Control Channel is an added channel to UMTS to increase downlink data rates. This is defined in Release 5 of the UMTS specifications. It
is also part of the HSDPA.
HS-SCCH uses a SF=128 and has q time structure based on a sub-frame of length 2 ms, i.e. the same length as the HS-DSCH TTI. The timing of HS-SCCH starts two slots
prior to the start of the HS-PDSCH sub frame.
The following 7 items information is carried on the HS-SCCH
• Modulation scheme(1bit) QPSK or 16QAM
• Channelization code set (7bits)
• Transport block size ( 6bits)
• HARQ process number (3bits)
• Redundancy version (3bits)
• New Data Indicator (1bit)
• UE identity (16 bits)
In each 2 ms interval corresponding to one HS-DSCH TTI, one HS-SCCH carries physical-layer signaling to a single UE.
As there should be a possibility for HS-DSCH transmission to multiple users in parallel (code multiplex), multiplex HS-SCCH may be needed in a cell. The specification
allows for up to four HS-SCCHs as seen from a UE point of view .i.e. UE must be able to decode four HS-SCCH.
Does this site need DL CE expansion as it’s having high DLHW expansion
The site has the following issues
•
high rejection of RRC connection due to
high MP load
•
CSSR_PS
•
CSSR_Speach
•
RRC request denied
First Step
The two Neighbors with qrxlevmin = -105 ,
hence the base line value is -111 , so traffic
pushed to our site and it is the major reason of
8089 congestion hence CE expansion done. And
also 60W activated , also 8563X &
1934 carrying very low traffic hence
•
Changed qrxlevmin of neighbors to -111
•
and also if it is possible try to balance the
traffic by Up-tilting
Second Step
But the site has a few Overshooting and covers
5Km
For Reducing IRAT HO form 3G2G
IUB
IUB Congestion
Iub congestion is a common reason for high number of failures after admission events.
Depending on the volume of traffic per service or RAB, certain QoS could be congested at the AAL2: All RABs
excluding HSDPA are configured to use Class A or Class B being these two mostly impacted by congestion. Most of
the time Class B is the first QoS to get congested leading to failures after admission events.
• Possible indicators :
•
•
•
Check for congestion at the Iub link (See below)
Check for E1 issues and history of alarms of E1s (for intermittent E1 alarms)
Possible solutions for Iub congestion :
•
•
•
•
Enable Directed retry (short term solution).
Correct possible AAL2 miss configuration at Node B, RNC and RXI (AAL2 profile must match in all entities)
Order new E1s (long term solution).
Change AAL2 QoS configuration depending on services request volume (CS voice, R99 data, HSDPA, etc).
• Low RRC Success Rate or Low RAB Success Rate
In case a poor RRC Success Rate is detected and neither Admission Blocks nor MP Load rejections can explain
such a degradation of the RRC Accessibility, then check these 2 counters:
pmNoRrcConnReqBlockTnCs
RRC CS failures due to congestion on the user plane (AAL2) or control plane (UniSaal or SCTP) of the transport
network.
pmNoRrcConnReqBlockTnPs
RRC PS failures due to congestion on the user plane (AAL2) or control plane (UniSaal or SCTP) of the transport
network.
IUB Congestion
City
City 1
City 1
City 1
City 1
Site
Site 1
Site 2
Site 3
Site 4
IUB Unavailability
pmTotalTimeIubLinkCongest
pmNoOfDiscardedNbapcMessages pmNoFailedAfterAdm
edDl
437868
262488
391
170304
59808
192
165246
70926
223
161658
69114
212
IUB Congestion
IubLinks/AbisLinks Status
str[12ft] Print status of the IubLinks/AbisLinks and their associated
Cells and Channels
RNCE1> str
151201-17:12:33 10.139.153.16 11.0b RNC_NODE_MODEL_V_3_4701 stopfile=/tmp/28429
0%
~50%
~100%
MOD IUBLINK
CELLNAMES
CFRPHEU1 CFRPHEU2 CFRPHEU3 CFRPHEU4 CFRPHEU5 CFRPHEU6 ICDS TN
TNPORTS
--------------------------------------------------------------------------------------------------------------------1054 Iub_UE1773X UE1773XA-1/1/1/2/2/2 111111 111111 111111 111111 111111 111111 1111 I
1055 Iub_UT9727X UT9727XA-1/1/1/2/2/2 111111 111111 111111 111111 111111 111111 1111 I
1064 Iub_UT7479X UT7479XA-1/1/1/2/2/2 111111 111111 111111 111111 111111 111111 1111 I
1065 Iub_UT9624X UT9624XA-1/1/1/2/2/2 111111 111111 111111 111111 111111 111111 1111 I
1085 Iub_UT9852X UT9852XA-1/1/1/2/2/2 111111 111111 111111 111111 111111 111111 1111 I
1094 Iub_UT9827X%1 UT9827XA-1/1/1/1/2/2 111111 111111 111111 111111 111111 111111 1111 I
1094 Iub_UT9827X%2 UT9827XC-2/2
111111 111111
1111 I
ollowing 42 sites are totally or partially unavailable:
--------------------------------------------------------------------------------------------------------------------MOD IUBLINK
CELLNAMES
CFRPHEU1 CFRPHEU2 CFRPHEU3 CFRPHEU4 CFRPHEU5 CFRPHEU6 ICDS
TN TNPORTS
--------------------------------------------------------------------------------------------------------------------3106 Iub_UT0320Z UT0320ZA-1/2
L000LL L000LL
L000 I
3136 Iub_UT7029X UT7029XA-1/1/1/2/2/2 L000LL L000LL L000LL L000LL L000LL L000LL L000 I
3155 Iub_UT9123X UT9123XA-1/1/1/2/2/2 LLLLLL LLLLLL LLLLLL LLLLLL LLLLLL LLLLLL L000 I
--------------------------------------------------------------------------------------------------------------------Cell availability: 920 of 1148 cells are up (80.1 %)
Site availability: 155 of 197 sites are fully operational (78.7 %)
Unlocked Cell availability: 920 of 942 unlocked cells are up (97.7 %)
HS availability: 920 of 1148 channels are up (80.1 %)
EUL availability: 920 of 1148 channels are up (80.1 %)
Iub/link problems
It was a specific case with severe degradation observed at busy hr. also observed Iub discards & HS Cap limiting ratio at
same times on impact of degradation
NBAP
• In the 3GPP UTRAN architecture, NBAP (Node B Application Part) is the signaling
protocol responsible for the control of the Node B by the RNC. NBAP is subdivided
into Common and Dedicated NBAP (C-NBAP and D-NBAP), where Common NBAP
controls overall Node B functionality, and Dedicated NBAP controls radio links to
specific UE. NBAP forms part of the Iub interface.
• Example 1: High Failures after Admission on Multiple sites in specific location due to
possible transport congestion as these sites also have high NBAP discards
• Command in RNC (NBAP Discard)
• High NBAP discards cause:
• MPload rejections
• DL Hw rejections,
DL code rejections,
• DL power rejections,
• UL HW rejections
NTP Server Reachability Fault Alarm (1)
• Alarm Cause
– IP network problems (The traffic on the network is disturbed. This can be
caused by high traffic load or a hardware fault.
– Communication problems toward NTP server Unable to communicate with
NTP server (due to misconfiguration or because the NTP server is
disabled.)
– Wrong IP address (IP address is invalid or it points to a host that is not an
NTP server.)
– DNS problems The DNS is not performing its task in translating domain
names into valid, up-to-date IP addresses.
– Wrong domain name DN (domain name) cannot be resolved, DN resolved
to a host that is not an NTP server, DN resolved to a non-existent host
NTP Server Reachability Fault Alarm (2)
The alarm is issued when a Network
Time Protocol (NTP) client detects a
‘‘not reachability’’ condition toward an
NTP Server, which has been
configured as an IP synchronization
reference.
Impact:
No impact on traffic, if there is a working
standby synchronization
reference. Otherwise, the Traffic
disturbances.
NTP Server Reachability Fault Alarm (3)
The HSDPA concept is based on the following
features:
•
•
•
•
•
•
Shared channel transmission
Higher-order modulation
Short transmission time interval (TTI)
Fast link adaptation
Fast scheduling
Fast hybrid automatic-repeat-request (ARQ).
HSDPA Scheduling
The HSDCPA channel is a shared channel that can be shared in time using its 2 msec Transmission time
interval (TTI) and codes where the SF 16 codes available for HSDPA can be shared between up to 4 users in
one TTI
EUL Channels
•
Uplink HSUPA channels
A variety of new channels have been introduced for HSUPA to enable the system to carry the
high speed data. These new channels are:
– E-DCH, the Enhanced Dedicated Channel: This HSUPA uplink channel carries on block
of data for each TTI (Transmission Time Interval). The E-DCH can be configured
simultaneously with one or more DCHs. In this way high speed data transmission can
occur at the same time and on the same UE as services that use the standard DCH.
As a low latency (delay) is one of the key requirements for the high speed uplink a short
TTI (Transmission Time Interval) of 2 ms is supported in addition to one of 10 ms. The
short TTI allows for rapid adaptation of transmission parameters and it reduces the enduser delays.
There is a balance to be determined for the TTI. It is found that the physical layer
processing is proportional to the amount of data to be processed, and accordingly the
shorter the TTI the lower the level of data per TTI. However for applications requiring
relatively low data rates, the overheads required with a 2 ms TTI may be unduly high. In
these circumstances a longer TTI is more appropriate.
–
–
The E-DCH is mapped to a set of E-DCH Dedicated Physical Data Channels.
E-DPDCH (Enhanced Dedicated Physical Data Channel): This HSUPA uplink channel
carries uplink user data. Each UE can transmit up to four E-DPDCH channels at a
spreading factor of SF256 to SF2. The number of E-DPDCHs s and their spreading factors
are varied according to the instantaneous data rate required. As an example of a typical
scenario, to achieve a 2 Mbps rate - the raw data rate of early devices - two SF2 EDPDCHs were required.
E-DPCCH (Enhanced Dedicated Physical Control Channel): This HSUPA channel carries
the control data required by the Node B to decode the uplink channels including the EDCH Transport Format Combination Indicator which indicates the block size,
retransmission sequence number, etc.
• Downlink HSUPA channels
A variety of new channels have been introduced for HSUPA to enable
the system to carry the high speed data. These new channels are:
• E-AGCH (Enhanced Absolute Grant Channel): This HSUPA channel
provides the absolute limit of the power resources, i.e. the serving
grant, that the UE may use. The channel is used to send scheduling
grants from the scheduler to the UE to control when and what data
rate the UE should be used. The E-AGCH is only sent by one NodeB
regardless of the number that the UE is communicating with. The
NodeB used is the one that has the main responsibility for the
scheduling operation. The E-AGCH is typically used for large changes
in data rate.
• E-RGCH (Enhanced Relative Grant Channel): This channel is used to
move the UE serving grant up, down or remain the same. This
HSUPA channel is generally used for relatively small changes during
an ongoing data transmission. Large changes are handled by the EAGCH.
• E-HICH (Enhanced DCH Hybrid ARQ Indicator Channel): This HSUPA
channel is used to provide the acknowledgement of the UE data
received by the Node B.
Paging
Paging Process
A paging message for a CS call to a certain UE is broadcasted to all cells
belonging to the LA in which the UE is registered. Accordingly, a paging
message for a PS connection is broadcasted to all cells in the RA in which
the UE is registered.
Paging is initiated upon request from the CN or triggered in UTRAN.
• UE terminating service request for PS or CS services (CN initiated). CN
initiated paging is applicable to UEs in idle mode.
• UTRAN initiated broadcast to inform UEs when System Information is
modified. UTRAN initiated paging is used whenever System Information
(e.g. information about cell selection/ reselection, addition/replacement
of neighbors, handover etc.) has been updated.
The paging record varies in length depending on whether it includes the
UE identity in terms of IMSI, TMSI, or P-TMSI. A PCH frame can carry one
“Paging Type 1” message of 10 ms and may contain between 3-5 paging
records, depending on whether the paging uses IMSI or TMSI/P-TMSI.
When the UE mode is Cell_FACH or Cell_DCH common or dedicated
physical channels are already in use and the paging message “Paging Type
2” will be used.
the paging attempts on the LAC went
to almost zero for few hours when the
issue started and BH attempts have
doubled since then. It seems that any
activity/change was done in Core on
the mentioned date
SDATE
INTERVAL
NE
CN INIT
PAGING
TO IDLE UE
LA
07-Nov-15
07-Nov-15
07-Nov-15
AH
AH
AH
RNCE2
RNCE1
RNCE3
4,910,031
5,298,166
4,325,182
CN INIT
PAGING
TO IDLE UE
CN INIT
PAGING TO
IDLE UE RA
0
0
0
11,414,735
13,442,153
9,273,015
CN INIT
PAGING
TO URA UE
UTRAN
INIT
PAGING
TO URA UE
UTRAN
Paging
Rejection
1,326
365
96
Battery test basic feature activation ?
HSDPA Flexible Scheduler
Features for improving the Throughput
Benefits
This feature provides the flexibility of trading system capacity with
fairness among users on cell level
Description
The scheduler transmits information to users on a per 2 ms TTI
(Transmission Time Interval) basis. Several aspects are considered when
deciding which Ues to transmit to. These aspects include:
• UE radio channel measurements, CQI (Channel Quality Indication), with the
potential of increasing system capacity by favouring users with good radio
condition.
• Delay and average bit rate, with the potential of increasing fairness among
users.
• Re-transmission, with the potential of favouring users with scheduled
retransmissions
Parameters:
The flexible scheduler is operator configurable on cell level to one of
the following strategies:
• Max CQI
• Proportional Fair - low fairness
• Proportional Fair - medium fairness
• Proportional Fair - high fairness
Round Robin (does not need Flexible Scheduler)
• Equal bit rate
o
Flexible Scheduler is a pre-requisite for Code Multiplexing and HSSCCH Power Control optional feature
Summary
HSDPA Code Multiplexing and HSSCCH Power Control
Features for improving the Throughput
Code multiplexing is a complementary method to time multiplexing (which was introduced in P4) that gives the possibility to share the HS-DSCH resource among users in both code and time domain,
thereby improving the overall performance in terms of system throughput and number of users served at a given delay HS-SCCH power control reduces the RBS output power needed for the HSSCCHs and
thereby increases the system capacity.
Description
Code multiplexing is a complementary method to time multiplexing that gives the possibility to share the HS-DSCH resource among users in both code and time domain. The scheduler can transmit
information to up to 4 users per 2 ms TTI (Transmission Time Interval) by using separate codes, or group of codes, per user. The codes to be received by a certain UE are signalled on HS-SCCH. HS-SCCH
power control exploits e.g. UE measurements to adapt the HSSCCH output power. In this way, users close to the RBS will have less HSSCCH output than users far away from the RBS. The overall target is to
reduce the average RBS output power needed for the HS-SCCHs. As such, the HSSCCH power control gain increases with the allowed number of users per TTI, c.f. code multiplexing.
Parameters
It will be possible for the operator to control:
• The number of HS-SCCHs for code multiplexing
• Operation of HS-SCCH power control by suitable parameters such as minimum and maximum HS-SCCH output power as well as update rate.
Benefits
This feature
• Improves the delay characteristics, especially for users downloading small objects, e.g. Web pages
• Improves the system throughput
• Reduces RBS output power for HS-SCCH signaling
Interference Suppression
The Interference Suppression is an advanced receiver enhancement for DUW. It brings significant performance gains for EUL, which in turn lowers
interference levels also for other radio bearers. Interference Suppression is supported in deployment scenarios with 1, 2, or 4 receiver antennas.
The Interference Suppression receiver replaces the existing G-Rake receiver and improves equalization, SIR estimation, and interference suppression
(interference mitigation) capabilities. The NodeBFunction::featureStateInterferenceSuppression
attribute controls whether the feature is enabled. The Interference Suppression licenses is required. This feature is only available for DU-based RBS.
EUL 2ms TTI increase
The EUL 2ms Transmission Time Interval (TTI) feature
provides:
• higher uplink bit rates
• lower latency.
The NodeBFunction::featureStateEul2msTti attribute
controls whether the feature is enabled. The EUL 2ms
TTI license is required.
Candidate RNC must has the following circumstances:
• Good number of average EUL best users
• Good UL RSSI
• Minimum UL hardware admissions
2ms TTI users admission
The 2ms TTI users admission
increase from 4 to 12. Overall we have
increase in both Cell and User
Throughput which increase in UL CEL
utilization, both static and dynamic
Moatch
cd mobatch
ls
Cell Disable due to RncNotAbleToScheduleSibs alarm
• Issue is related to wrong relation plan. There was relation creation and cell parameter
Unbalance MaxTotalOutputPower in RRUS 12
CE congestion
The CE congestion suffers this site. The overshoot and capacities
(as below) were checked. There is not overshooting . Finally it
should be reduced the TTI2 from 6 to 4
SHO degradation due to many alarms
Direct Retry IRAT HO
high rejections due
to overshooting
•
IRAT affected due to increasing attempts of
directed retry due to power congestion in
some cpichpower increased sites
CE congestion Issue after expansion
Power Congestion
The mentioned site encounters the PWR Congestion,
after expansion it suffers the CE Congestion.
After Expansion the site encounter the CE Congestion
The ulHwAdm must be set at high level (99)
Sometimes the RbsChannelElementsUplink has low
value and the ULHW must be expand
High UL RSSI
Issue: The UL RSSI reading on Node B is high (ranging -70
to -80 dBm) while normally should be -100 to -108
Causes:
•
Subscriber behavior (UE with high RSSI)
• interfered area by RF signal (jammer)
• Tx link fluctuation
• Congested Transmission Link
• TMA is installed but it is not defined
• when it is accompanied by abnormal Drops and there
is nothing to suggest bad radio conditions such as
overshooting, there is a high possibility that it has got
some Rx path hardware issue
•
•
In last case, this is generally rectified by the site
engineer, replacing the faulty RU, feeder, antenna etc.
non-traffic interference
•
High TX power from a UE that are connected to a far
cell. This can happen due to missing neighbors
RTWP Vs. RSSI
High UL-RSSI due to missing
Neighbors
The site’s cells suffer the high UL-RSSI in general but at 15th Nov. it
enhanced more. It re-homed from BSC to another one in 2G part at
that time, and also the IRAT HO with relocation has degraded.
the inter system relation definition should be revised.
High UL-RSSI due to
Congested link
Link between two sites is congested and
causing low RSSI
DL traffic ps16 and ps128
has been increased on RNC
One site had very high DL H/W congestion and almost no HS/Eul
traffic since the 7th. CV has been re loaded and is now taking Eul/HS
traffic.
Payload and throughput degrade
due to UGW
An issue with UGW which has affected
both 3G as well as 2G’s payload and
throughput.
All UGWs affected in Region due to
possible Gi Interface issue
Alarm that affect Traffic
Sector C is not taking any traffic and has the
following alarm
Date & Time (Local) S Specific Problem
MO (Cause/AdditionalInfo)
====================================================================================================================
2014-11-28 07:09:40 C License Key File Fault
Licensing=1 (No license key file installed. IntegrationUnlock=ACTIVATED, 16 days remaining)
2014-11-28 07:09:52 m InconsistentConfiguration
Subrack=1,Slot=1,PlugInUnit=1,EcPort=1 (Attribute hubPosition is empty or not valid)
2014-11-28 07:12:18 M DigitalCable_CableFailure
DigitalCable=3_1_RI_C (DN2:
SubNetwork=ONRM_ROOT_MO_R,SubNetwork=RNCE2,MeContext=1601X,ManagedElement=1,Equipment=1,Subrack=1,Slot=1,PlugInUnit=1,PiuDevice=1,DeviceGroup=DUI DN3:
SubNetwork=ONRM_ROOT_MO_R,SubNetwork=RNCE2,MeContext=1601X,ManagedElement=1,Equipment=1,SectorAntenna=3-1,AuxPlugInUnit=RRUW-1,RruDeviceGroup=1)
2014-11-28 10:08:51 M NTP System Time Sync Fault
ManagedElementData=1 (additionalInfo: NTP general problem)
Case: Speech Drop
Issue:
High speech drops on
one site due to
overshooting
Solution:
RET installation has been
requested. CPICH power
reduced by 1 dB
temporarily
DCR HS
DCR HS degraded due to hardware issues in a site, specifically alarms
such as temperature exceptionally high and Piu conn lost are toggling.
Emergency License
This site has very high power congestion since it came on.
As it’s on Emergency license. 80 watts for sector C and 60
for the others have been activated . Request for 60 Watt
expansion for ll sectors as it will again be congested once
the EM License expires. In addition to the power
admission for Sector C has been increased to 95. In site
life we can use only 2 times
MP Load
The module MP handles signaling associated with traffic
events. Connection setup and release (Speech, PS R99, HS, LA
update, SMS).
RncModule: Create this MO on the MP to group IubLinks in a
way to minimize inter-processor communication
variations in packet delay along the path,
i.e. packet delay variation (PDV), also impacts accuracy
(Synchronization Ericsson WCDMA doc)
Total number of pages discarded due to central MP load
control for a RNC pmNoPageDiscardCmpLoadC
Subrack Identity
Local Distinguished Name
Description
Main Subrack
ManagedElement=1,Equipment=1,Subrack=MS
The MS in an RNC.
Extension Subrack
ManagedElement=1,Equipment=1,Subrack=ES-2
The 2nd ES in an RNC.
Slot in MS
ManagedElement=1,Equipment=1,Subrack=MS,Slot=7
The 7th board in the MS.
Slot in ES-2
ManagedElement=1,Equipment=1,Subrack=ES2,Slot=12
The 12th board in the
second ES
UtranCell=7105XC2
pmNoRejRrcConnMpLoadC
15847
UtranCell=7105XC1
pmNoRejRrcConnMpLoadC
15444
UtranCell=7105XB2
pmNoRejRrcConnMpLoadC
14532
UtranCell=7105XB1
pmNoRejRrcConnMpLoadC
13764
UtranCell=7105XA2
pmNoRejRrcConnMpLoadC
9979
• Load control refers to the RNC MP load
• MP implements overload protection
• Load control applies prior to RL setup
(subject to RN AC)
• If MP load exceeds 85%, RRC setup requests
are rejected
• MP load: observed with counters of the
LoadControl MOC
• Failures due to MP load:
pmNoRejRrcConnMpLoadC
Device failure
high failures after admission on multiple sites occurred
Device ES-1-11 and ES-2-16 locked and issue has recovered.
NBs which are attached to particular device will be
automatically be shifted to other active devices.
But definitely if the MP load on other devices will increase and
if the other devices are already on a high load, it might result in
MP load rejection on that particular device, that’s why its
always recommended to check the RNC MP load before locking
any devie.
lget iublink=iub. rncmodule
lget iublink=iub. rncmodule RncModule=ES-2-17-4
Co-Scrambling Code
Two Sites have the Same Scrambling code for all
Cells (all sectors have primaryScramblingCode=0)
After changing the Scrambling code, the
improvements have achieved.
CSSR_PS due to MPLOAD
high traffic sites and DL CE congestion has
increased after URA implementation.
For Cope with the DL CE in site level
• change dlHwAdm to 99, sf16Adm to 0
• sf16gAdm to 0
RRC level code congestion (pmNoRrcreqdeniedAdmDlChanlCode)
numhsscchcodes (34) increased
RNC>get UtranCell=1805XA1, numHsScchCodes
Definition???
dlcodeadm (90 99)
RNC> get 1805 dlcodeadm
Definition???
Speech Drops due to Power Congestion
The releaseAseDl parameter minimizes the speech drops caused by DL power congestion
Parameter Description:
Amount of ASE in the downlink to be released with each periodic congestion-resolution action targeting the guaranteed traffic class connections
in this cell. 0 indicates that no ASE is released for guaranteed traffic class connections. This prevents congestion-resolution actions on the
guaranteed traffic class connections in the cell. Range: 0 to 500, Default=1
Changing the value from default 1 to 0 means, now congestion control will not release a guaranteed traffic class connection.
The releaseAseDlNg uses for the non-guaranteed traffic
UL Sync Drops
This specific cell is suffering from high UL Sync drops since the 26th with loss of traffic. The delta between RSSI in Sector C for carrier 1 which is ~10 dB . We must arrange to visit the site.
pmNoSysRelSpeechUlSynch
Number of system disconnections due to lost uplink synch for calls that included
any CS Conversational Speech RAB (including AMR Single-mode 12.2, AMR-NB
Multi-mode single- and multi-rate, and AMR-WB).
Condition: Incremented by one in the best cell in the active set prior to the call
release, when a CS Conversational Speech call is released by the network after
expiry of the timer defined by Rrc::dchRcLostT.
LKF (License Key File)
CSSR degradation due to frame lost
Site having transmission problems.
The PM counter counts lost or discarded HS-DSCH data frames in RBS.
For instance, Spi02 is valid for scheduling priority class 02 The SPI and
GBR are the two primary parameters that can be used to control the
QoS differentiations on HSDPA. The GBR can be set for a user with
minimum target bit rate while the SPI can be set to give priority to
data flow to achieve that target.
HS Frame Lost due to IuB congestion
high Iub HS/EUL capacity
limitations & HS Frames Lost
RNC
RNCE2
RNCE2
RNCE2
RNCE2
RNCE2
Sie
9519X
7557X
9747X
7062X
7042X
Average of
MAX(PMCAPALLOCIUBHSLRSPI01)
87.5
86
85.5
85.66666667
85.66666667
Average of EUL_LIMITING_RATIO
0.00
0.00
0.00
0.05
0.00
Average of
HS_FRAMES_LOST_RATIO
22.50%
21.17%
21.15%
21.10%
20.64%
Check the Max and Min Tilt for calibration
Calibrating the RET
A calibration of the RET is performed to find the limits of the antenna tilt and the actuator is driven through the whole tilt range of the controlled antenna
element.
Before calibrating an RET, a connection to the ARETU or RETU must be established.
To calibrate an RET, start the action forceCalibration in the RetDevice MO.
Cabinet change activity on site
(Discrepancies in R99 ADM parameters)
Baseline settings were
changed by Field team
during DUW change
activity
• Maxnumeulusers
• Maxnumhsdpausers
• NumHsPdschCodes
• Maxtotaloutput power
RNC
Wrong
Values
Correct
Values
sf128A
dm
incons.
Count
sf16Ad
m
incons.
Count
sf16Ad
m UL
incons.
Count
sf16gA
dm
incons.
Count
sf32Ad
m
incons.
Count
sf4Ad
m
incons.
Count
sf64Ad
mul
incons.
Count
sf8Ad
m
incons.
Count
sf8Ad
mul
incons.
Count
sf8gAd
mul
incons.
Count
0
42
48
48
0
54
0
12
32
32
128
0
32
16
32
0
100
0
0
0
###############################################################################
MO Class
Attribute
Type
Flags
###############################################################################
UtranCell
sf128Adm
long
-----------------------------------------------------------------------------------------------------------------------------------Admission limit for non-guaranteed traffic class connections with downlink Spreading Factor (SF) =
128. This is the maximum number of radio links with SF=128 in the downlink for which new
admission requests for non-guaranteed traffic classes will continue to be allowed. Reaching or
exceeding this number of downlink SF=128 radio links (for non-guaranteed service classes) will
block setup in this cell of more non-guaranteed traffic class radio links that would require downlink
SF=128. Note that for this particular admission limit, soft and softer handovers are not blocked
(though inter-frequency handovers may be blocked).
The value 128 disables the admission policy, meaning that no blocking of downlink SF=128
requests will occur.
Change takes effect: Immediately
Range: 0 to 128, Default=128
HS average Number of UE in Queue
HsAqmCongCtrlLicenseNotValid alarm:
When this alarm is generated and license
key is disable, the cell configured for AQM
based Congestion Control for HSDPA is
not possible to setup.
pmSumNonEmptyUserBuffers
HS_AVG_NO_UE_IN_QUEUE =
(pmNoActiveSubFrames + pmNoInactiveRequiredSubFrames)
CommunicationLostWithRet alarm
By this alarm you cannot change the electrical tilt
This alarm will generally require an RE to go to site. Communication with the ASC/RET is lost. The consequence of this alarm
is that planning/optimization will be unable to make a tilt change to the affected sector. Connection with the RET will need to
be restored on site or a replacement ASC will be needed.
RBS (actions):
• Alt
*show current alarms
• lga | grep AuxPlugInUnit_CommunicationLostWithRet
*show history of current alarm
• get radio no
*confirm if node is carrying traffic
• st plug
*print state of all plug in units
• Prox *do a get on the disabled proxy number
• Get ret electrical
• acl xxx *check what action you can perform on the proxy number
• acc xxx restartAuxUnit *try restart the ASC/RET using the proxy number
RNC (Action):
• moshell XXRNCX *log onto the RNC
• lt all *load all Managed Objects
• alt *show current alarms
• lst .xxxx *show status of channels
failed After ADM
Carrier_SignalNotReceivedWithinTime alarm
Site Down (TxDeviceGroup_GeneralSwError)
The likely causes of this alarm are the following:
• A software fault
• An incorrect version of the software
• A faulty configuration, depending on a software error (only when RruDeviceGroup issues the
alarm)
In this case it is the TX board that has the problem. As a consequence the capacity of the site is
decreased.
• RBS:
–
–
–
–
–
alt *show current alarms
cab *confirm the TX boards on the site
st plug *check the state of the TX boards
acl xxx *check what action you can perform on the board using the proxy number
acc xxx manualRestart *try restart the board
Check that the alarm has cleared. If the alarm is still present an RE will need to go to site and do a
hard reset or change the TX board. Confirm the site is carrying traffic.
CSSR Degradation
High failed-after-adm at two NBs;
suspected TXN issue (PDV alarm)
Code Congestion
It recovered after RBS reset
High power congestion in site due to RRU
Attenuation Discrepancy
Affect of PWR congestion on IRAT and SHO
The PWR congestion is not very affective on IRAT but in SHO is affective
CSSR-DCR degradation
Site performance degraded due to false configurations
1) get . licensecap
2) get . dlatten
3)get . maxtot
4) get . maxdlpower
maxDlPowerCapability=maxTotalOutputPower dlAttenuation
For instance:
80 wat per cell, 40 watt per carrier (=46 dBm)
Then maxDlPowerCapability (460-7=453)
Find the type of DU and RU, Temp,
VSWR and Board Serial No.
Find VSWR
Frame Synchronization
In the downlink direction, frames are synchronized in order to be
transmitted in the air interface at a certain transmission time. The
Frame Synchronization function also provides a base for macrodiversity functionality. Frame transport timing is supported within a
Serving Radio Network System (SRNS) as well as between two RNSs.
The Frame Synchronization function also provides timing and
numbering of the traffic frames to be transported over the Iub
interface between an RNC and its associated RBS. The function
applies to R99 common channels FACH and PCH and dedicated
channels R99 DCH. For the data transfer on RACH and BCH, there is
no Frame Synchronization related functionality in the RNC. For HSDCH (HSPA channels), scheduling is the responsibility of the RBS,
and thus the Frame Synchronization function is not used.
High Failures after admission and Sector C has
very high UL Sync drops and loss of traffic
Alarm history: lga -a
feeder disconnection and also synchronization issue
was the major issue
PS and CS CSSR Degradation?
Due to wrong configuration
The baseline script was run and
some values are default and wrong
BLER
UL_BLER = 100 ∗
PMFAULTYTRANSPORTBLOCKSBCUL
PMTRANSPORTBLOCKSBCUL
pmTransportBlocksBcUl
-----------------------------------Total number of uplink DCH transport
blocks.
Condition: Incremented by one for each
valid transport block (based on the CRCI)
received on UL DCH, before macro
diversity combining.
PMFAULTYTRANSPORTBLOCKSBCUL----------------------------------Total number of faulty uplink DCH
transport blocks.
BLER Degradation
After activation of URA_PCH in RNCE the UL_BLER has degraded.
UL_BLER
= 100 ∗
PMFAULTYTRANSPORTBLOCKSBCUL
PMTRANSPORTBLOCKSBCUL
URA Update Success Rate (DUW Faulty)
URA_UPDATE_SUCC = 100*(pmNoUraUpdSuccess/pmNoUraUpdAttempt)
Failures after admission (CSSR/Soft HO)
•
•
•
•
•
•
•
•
•
•
•
•
RU Fault
TN Blocking
Iub congestion
NBAP Discards
License expansion
Carrier_SignalNotReceivedWithinTime alarm
HW swap and CPRI cables
NTP Server alarms (NTP Sync Faults alarms)
Transmission Issue
DUW faulty
HW Alarms_LKF issue after 3rd carrier addition
False configurations (maxDlPowerCapability)
CSSR (Baseline parameter was not set correctly )
CSSR (CLOCK Synch alarms )
CSSR (CLOCK Calibration alarms)
DCR
Firstly the DUW was fault after
investigation it found that the
PSU was faulty and it’s replaced.
Issue is rectified and DUW is
working normally
Low IRAT HO
The IRATHO is poor due to the following issue
1. High ICM which is causing IRAT HO failures.
2. High TCH assignment failure rate which is also
causing poor IRAT performance for 3G site.
The following activities to be done to maintain and improve IRAT performance:
• High Failure Relations deletion except Co-site.
• SelectionPriority tuning based on succeeded IRAT attempts (detail information will be
shared accordingly).
• Periodic ExternalGsmCell definition audit
• Penalizing poor performing GSM cells using individualoffset. (detail information will be
shared accordingly).
• Tuning the gsmAmountPropRepeat from 1 to 0.
• Tuning the gsmThresh3a from -95 to -85 to attempt only in good radio conditions on
GSM.
Sleeping Cell
Sleeping Cell 1
Cell is sleep due to SFP
faulty (Small
Form-factor Pluggable)
Sleeping Cell 2
The cell is sleeping periodically
due to RRUS faulty
Sleeping Cell 3
Digital Cabling Fault
Sleeping Cell 4
High VSWR
Sleeping Cell 5
Tr device failures
Sleeping Cell 6
The cell is not taking any traffic due to
Carrier_RejectSignalFromHardware alarm
Sleeping Cell 7
The cell is not taking any traffic due to high RSSI
Sleeping Cell 8
Disable from RNC side
DCR
•
•
•
•
•
•
•
•
•
•
•
•
DUW is faulty
RETU alarm
Overshooting
Digital cable failure alarm
TX problem
Iub congestion
Code/User/Pwr Congestion
RSSI
PSU Faulty
LKF issue
RRUS faulty
High VSWR
Sectors are not propagating
Sometimes the RRUs/RUs get freeze due to some internal processor failure or high temperature which is not
always be visible via alarms. And it stops setting up new RRC connection. If you see when the RU stopped
propagation it also stopped setting up new RRC connection. And finally the NodeB was restarted
Give priority to neighbors based on GSM attempt
Important parameter &
counters details
Capacity management
•
•
•
•
compModeAdm: Absolute admission limit for the number of radio links in compressed mode in a cell. (15)
dlCodeAdm: Parameter that defines in percentage the absolute admission limit for DL code usage (90, 95, 97)
pwrAdm: Parameter that defines in percentage the absolute admission limit for DL power utilization. (85 or 95)
sf8Adm: Defines the absolute admission limit for the number of RLs with SF=8 (PS384) in DL. (0)
•
sf16Adm: Defines the absolute admission limit for the number of RLs with SF=16 (PS128 RAB) in DL. (32)
–
•
•
•
•
Admission limit for non-guaranteed traffic class connections with DL SF = 16. Maximum number of radio links with Spreading Factor
sf32Adm: Defines the absolute admission limit for the number of RLs with SF=32 (PS64) in DL. (32)
sf4AdmUl: Absolute admission limit for the number of RLs with SF=4 in UL (PS384/HS) (0)
sf8AdmUl: Defines the absolute admission limit for the number of RLs with SF=8 in UL. (0)
sf16AdmUL: Parameter that defines absolute admission limit for the number of RLs with SF=16 in UL. (32)
system configuration
• primaryCpichPower: Parameter that controls the power level of the Primary CPICH.
• maximumTransmissionPower: Parameter that can be used to limit the total DL power in a cell to a value
lower than DL power capability of the RBS. (441, 442, 460…)
• maxTxPowerUl: Used in UE functions for cell selection/ re-selection in idle mode and connected mode and
also used by UTRAN to control the maximum transmitted power level a UE can use. (for
ExternalGsmNetwork =100 and for UtranCell=24)
Directed retry
• loadSharingDirectedRetryEnabled: An RNC-wide flag for turning
on the feature.
• directedRetryTarget: UA cell specific parameter that specifies the
Directed Retry target in terms of a cell reference to an external
GSM cell.
• loadSharingGSMThreshold: A cell specific parameter that
specifies the load sharing threshold below which Directed Retry
to GSM is suppressed.
• loadSharingGSMFraction: A cell specific parameter that specifies
the fraction of qualified speech calls to be diverted to GSM.
handover
•
•
•
•
•
•
•
•
•
maxActiveSet: Maximum number of cells allowed in the Active Set.
IndividualOffset: Offset value which can be assigned to each cell. It is added to the measurement quantity before the UE evaluates whether or not an event
has occurred. It can either be positive or negative value.
measQuantity1: Defines the measurement quantity for intra-frequency reporting evaluation. Default is Ec/No.
hsQualityEstimate: Indicates whether Ec/No or RSCP should be used for indicating "best cell" for HS-DSCH Cell Change. Default is RSCP.
reportingRange1a: Relative threshold referred to the CPICH of the best cell in the Active Set used as evaluation criteria for event 1a (a primary CPICH enters
the reporting range).
reportingRange1b: Relative threshold referred to CPICH of the best cell in the Active Set used as evaluation criteria for event 1b (a primary CPICH leaves the
reporting range).
reportingInterval1a: Time between periodic reports at event-triggered periodic reporting for event 1a
timeToTrigger1a: If event 1a condition is fulfilled during at least a time greater than or equal to timeToTrigger1a milliseconds, then event 1a occurs.
timeToTrigger2dEcno: If event 2d condition is fulfilled during at least a time greater than or equal to timeToTrigger2dEcno milliseconds, then event 2d
occurs
Hasdpa/eul
•
•
•
•
•
•
•
numHsPdschCodes: Parameter that defines the number of codes allocated in a call only for HS-PDSCH (SF 16).
maxNumHsPdschCodes: Defines the maximum number of HS-PDSCH codes that may be allocated in a cell.
hsdpaUsersAdm: Cell parameter that defines the admission limit for the number of users assigned to the HS-DSCH. Applicable to admission requests
related to RAB setup of an HSDPA service.
maxNumHsdpaUsers: Limits the maximum allowed number of simultaneous HSDPA users per cell that can be served.
eulServingCellUsersAdm: Defines the admission limit for the number of EUL users having the cell as serving cell.
eulNonServingCellUsersAdm: Cell parameter that defines the admission limit foe the number of EUL users having the cell as non-serving cell.
hsdschInactivityTimer: Time during which throughput has to be low in order to trigger a down-switch (dedicated to common state) for a UE in state
DCH/HS or in state EUL/HS.
Idle mode
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
qQualMin: Minimum required quality level in the cell measured in the UE.
qRxLevMin: Parameter that indicates the min. required signal strength in the cell
qualMeasQuantity: Used for decision as to whether the 3G ranking for cell selection and reselection is based on Ec/No or RSCP. Default is Ec/No.
qHyst1: Hysteresis values used for serving cell, when ranking is based on CPICH RSCP
qHyst2: Hysteresis values used for serving cell, when ranking is based on CPICH Ec/No
qOffset1sn: Signal strength offset b/w source and target cell for cell ranking based on CPICH RSCP.
qOffset2sn: Signal offset between serving cell and neighbor cell, based on CPICH Ec/No.
sIntraSearch: Decision on when intra-freq. measurements should be performed. Following criteria is used:
sIntraSearch ≥ qQualmeas - qQualMin (where qQualmeas is the value measured by UE )
sInterSearch: Parameter is used to make decision to start inter-freq. measurements.
sInterSearch ≥ qQualmeas - qQualMin (where qQualmeas is the value measured by UE )
sRatSearch: Decision on when GSM measurement should be performed in relation to qQualMin.
sRatSearch ≥ qQualMeas – qQualMin (where qQualmeas is the value measured by UE )
sHcsRatSearch: Decision on when GSM measurement should be performed in relation to qRxLevMin.
sHcsRatSearch ≥ qRxLevMeas – qRxLevMin (where qRxLevMeas is the value measured by UE)
IRAT
•
•
•
•
•
usedFreqThresh2dRscp: Threshold for event 2d (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold)
based on RSCP measurements.
usedFreqThresh2dEcno: Threshold for event 2d (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold)
based on Ec/No measurements..
gsmThresh3a: Threshold for event 3a (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold and the
estimated quality of the GSM system is above a certain threshold) for GSM.
gsmPropRepeatInterval: Minimum time interval between proposals of the same GSM cell for handover based on the same measurement report.
gsmAmountPropRepeat: Maximum number of repeated proposals (not including the first proposal) of GSM cells for handover based on the same
measurement report.
RRC Connection Setup Counters
•
•
•
•
•
•
•
•
•
pmTotNoRrcConnectReq: Number of RRC Connection Requests
pmTotNoRrcConnectReqSuccess: Number of successful RRC Connection Requests
pmNoRrcReqDeniedAdm: Number of RRC requests denied by admission control
pmTotNoRrcConnectReqCs: Number of Conversat. and Emerg. call RRC Connection Requests
pmTotNoRrcConnectReqCsSucc: Number of successful Conversat. and Emerg. Call RRC requests
pmNoRrcCsReqDeniedAdm: Number of CS calls denied by Admission Control
pmTotNoRrcConnectReqPs Number of Int. and Background RRC Connection Requests
pmTotNoRrcConnectReqPsSucc Number of Successful Int. and Background RRC Conn attempts
pmNoRrcPsReqDeniedAdm Number of PS calls denied by admission control
RAB Establishment
•
•
•
•
•
•
•
pmNoRabEstablishAttemptSpeech: Number of RAB establishment attempts for speech
pmNoRabEstablishSuccessSpeech: Number of successful RAB establishments for speech
pmNoRabEstablishAttemptPacketInteractive: Number of successful RAB establishments for PS Int. RAB
pmNoRabEstablishAttemptPacketInteractiveHs: No. of RAB estab. att. for PS Int. RAB mapped on HS-DSCH
pmNoRabEstablishSuccessPacketInteractiveHs: No. of successful RAB estab for PS Int. RAB mapped on HSDSCH
pmNoRabEstablishAttemptPacketInteractiveEul: No. of RAB est. att. for PS Int. RAB mapped on EDCH/HSDSCH.
pmNoRabEstAttemptPsIntNonHs: No. of RAB establishment att. for PS Int. RAB in a non-HS (DCH or FACH) config.
pmNoRabEstSuccessPsIntNonHs: No. of succ. RAB establish. for PS Int. RAB in a non-HS (DCH or FACH) config.
Retainability Counters
•
•
•
•
•
•
•
•
pmNoNormalRabReleaseSpeech: Number of successful normal RAB releases (Speech)
pmNoSystemRabReleaseSpeech: Number of successful system RAB releases (Speech drops)
pmNoNormalRabReleasePacket: Number of successful normal RAB releases (PS)
pmNoSystemRabReleasePacket: Number of successful system RAB releases (PS drops)
pmNoNormalRbReleaseHs: Number of successful normal releases of packet RABs mapped on HS-DSCH
pmNoSystemRbReleaseHs: Number of successful system releases of packet RABs mapped on HS-DSCH
pmNoNormalRbReleaseEul: Number of normal RAB releases of PS Int. RAB mapped on E-DCH/HS-DSCH
pmNoSystemRbReleaseEul: No. of system RAB releases of PS Int. RAB mapped on E-DCH/HS-DSCH
IRATs
•
•
•
•
•
•
•
pmNoDirRetryAtt: Number of attempted outgoing inter RAT HO due to capacity
pmNoDirRetrySuccess: Number of successful outgoing IRAT HO due to capacity
pmNoAttOutIratHoSpeech: No. of attempted outgoing IRAT HO for speech
pmNoSuccessOutIratHoSpeech: No. of successful outgoing IRAT HO for speech
pmNoFailOutIratHoSpeechGsmFailure: No. of failed outgoing IRATs due to GSM allocation failure
pmNoFailOutIratHoSpeechReturnOldChPhyChFail: No. of failed outgoing IRATs due to physical channel failure,
where UE returns to present active set
pmNoFailOutIratHoSpeechReturnOldChNotPhyChFail: No. of failed outgoing IRAT HOs due to reasons other
than physical channel failure, where UE returns to present active set.
Handover
• pmNoTimesRlAddToActSet: Number of times RL is added/ replaced to an active set
• pmNoTimesCellFailAddToActSet: Number of times a cell fails to be added to an active set
• pmNoRlDeniedAdm: Number of RL setups or RL addition requests denied by admission
Availability
•
•
•
•
•
•
pmCellDowntimeMan: Time that cell has been unavailable because of admin state being manually locked.
pmCellDowntimeAuto: Time that cell has been unavailable due to a fault
PmHsDowntimeMan: Time that HSDSCH in a cell is unavlbe. due to operation settings
pmHsDowntimeAuto: Time that HSDSCH in a cell is unavailable due to system taking cell as down
pmEulDowntimeMan: Time that Eul srvc in a cell is unavailable due to operator settings
pmEulDowntimeAuto: Time that Eul service is unavailable bcs the system has considered the cell as down
Transport (Iub)
•
•
•
•
•
•
pmSuccInConnsRemoteQosClassA: No. of successful establishments of incoming connections on this AAL2 Access Point (AP).
The counter increments in terminating node.
pmSuccOutConnsRemoteQosClassA: No. of successful establishments of outgoing connections on this AAL2 Access Point.
The counter increments in terminating node.
pmUnSuccInConnsLocalQosClassA: Number of unsuccessful attempts to allocate AAL2 path resources during establishment
of incoming connections
pmUnSuccInConnsRemoteQosClassA: No. of unsuccessful estab. of incoming connect. on this AAL2 AP caused by the reject
in remote node. Increments in a Terminating node
pmUnSuccOutConnsLocalQosClassA: Number of unsuccessful attempts to allocate AAL2 resources during establishment of
outgoing connections on this Access Point
pmUnSuccOutConnsRemoteQosClassA: Number of unsuccessful establishments of outgoing connections on this AAL2
Access Point (AP).
Admission Control
•
•
•
•
•
•
•
•
•
pmNoFailedRabEstAttemptLackDlHw: Number of failed RAB establishments attempts due lack of DL hardware resources
pmNoFailedRabEstAttemptLackUlHw: Number of failed RAB establishments attempts due to lack of UL hardware resources
pmNoFailedRabEstAttemptLackDlAse: Number of a failed RAB establishments attempts due to lack of DL ASE
pmNoFailedRabEstAttemptLackUlAse: Number of failed RAB establishments attempts due to lack of UL ASE
pmNoFailedRabEstAttemptExceedConnLimit: No. of failed PS RAB estab att due to exceeding SF (8,16,32) connection limit
pmNoFailedRabEstAttemptLackDlChnlCode: No. of failed RAB estab attempts due to lack of DL channelization codes
pmNoFailedRabEstAttemptLackDlPwr: Number of failed RAB establishment attempts due to lack of DL power.
pmNoFailedAfterAdm: No. of RRC or RAB establishments failed after being admitted by admission control.
pmNoReqDeniedAdm: No. of RAB establishment and RRC requests rejected by admission control
Drop Reasons
•
•
•
•
pmNoSysRelSpeechNeighbr: No. of sys disconnects of a speech call due to missing (non-valid) neighbor relation
pmNoSysRelSpeechSoHo: No. of system disconnects of a speech call due to soft handover (valid/non-valid)
pmNoOfTermSpeechCong: Number of Speech Radio Connections served by RNC terminated due to congestion
pmNoSysRelSpeechUlSynch: Number of system disconnects of a speech call due to lost UL synch
Transmission
• pmEs: Transmission Errored Seconds
• pmSes: Transmission Severely Errored Sec.
• pmUas: Transmission Unavailable Seconds
Ericsson Important Optimization Parameters (1)
System Configuration
primaryCpichPower: Parameter that controls the power level of the Primary CPICH.
maximumTransmissionPower: Parameter that can be used to limit the total DL power in a cell to a value lower than DL power capability of the RBS.
maxTxPowerUl: Used in UE functions for cell selection/ re-selection in idle mode and connected mode and also used by UTRAN to control the maximum transmitted power level a UE can use.
Capacity Management
compModeAdm: Absolute admission limit for the number of radio links in compressed mode in a cell.
dlCodeAdm: Parameter that defines in percentage the absolute admission limit for DL code usage
pwrAdm: Parameter that defines in percentage the absolute admission limit for DL power utilization.
sf8Adm: Defines the absolute admission limit for the number of RLs with SF=8 (PS384) in DL.
sf16Adm: Defines the absolute admission limit for the number of RLs with SF=16 (PS128 RAB) in DL.
sf32Adm: Defines the absolute admission limit for the number of RLs with SF=32 (PS64) in DL.
sf4AdmUl: Absolute admission limit for the number of RLs with SF=4 in UL (PS384/HS)
sf8AdmUl: Defines the absolute admission limit for the number of RLs with SF=8 in UL.
sf16AdmUL: Parameter that defines absolute admission limit for the number of RLs with SF=16 in UL.
Directed Retry
loadSharingDirectedRetryEnabled: An RNC-wide flag for turning on the feature.
directedRetryTarget: UA cell specific parameter that specifies the Directed Retry target in terms of a cell reference to an external GSM cell.
loadSharingGSMThreshold: A cell specific parameter that specifies the load sharing threshold below which Directed Retry to GSM is suppressed.
loadSharingGSMFraction: A cell specific parameter that specifies the fraction of qualified speech calls to be diverted to GSM.
Handover
maxActiveSet: Maximum number of cells allowed in the Active Set.
IndividualOffset: Offset value which can be assigned to each cell. It is added to the measurement quantity before the UE evaluates whether or not an event has occurred. It can either be
positive or negative value.
measQuantity1: Defines the measurement quantity for intra-frequency reporting evaluation. Default is EcNo.
hsQualityEstimate: Indicates whether Ec/No or RSCP should be used for indicating "best cell" for HS-DSCH Cell Change. Default is RSCP.
reportingRange1a: Relative threshold referred to the CPICH of the best cell in the Active Set used as evaluation criteria for event 1a (a primary CPICH enters the reporting range).
reportingRange1b: Relative threshold referred to CPICH of the best cell in the Active Set used as evaluation criteria for event 1b (a primary CPICH leaves the reporting range).
reportingInterval1a: Time between periodic reports at event-triggered periodic reporting for event 1a
timeToTrigger1a: If event 1a condition is fulfilled during at least a time greater than or equal to timeToTrigger1a milliseconds, then event 1a occurs.
timeToTrigger2dEcno: If event 2d condition is fulfilled during at least a time greater than or equal to timeToTrigger2dEcno milliseconds, then event 2d occurs
Ericsson Important Optimization Parameters (2)
HSDPA/EUL
numHsPdschCodes: Parameter that defines the number of codes allocated in a call only for HS-PDSCH (SF 16).
maxNumHsPdschCodes: Defines the maximum number of HS-PDSCH codes that may be allocated in a cell.
hsdpaUsersAdm: Cell parameter that defines the admission limit for the number of users assigned to the HS-DSCH. Applicable to admission requests related to RAB setup of an HSDPA service.
maxNumHsdpaUsers: Limits the maximum allowed number of simultaneous HSDPA users per cell that can be served.
eulServingCellUsersAdm: Defines the admission limit for the number of EUL users having the cell as serving cell.
eulNonServingCellUsersAdm: Cell parameter that defines the admission limit foe the number of EUL users having the cell as non-serving cell.
hsdschInactivityTimer: Time during which throughput has to be low in order to trigger a down-switch (dedicated to common state) for a UE in state DCH/HS or in state EUL/HS.
IRAT
usedFreqThresh2dRscp: Threshold for event 2d (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold) based on RSCP measurements.
usedFreqThresh2dEcno: Threshold for event 2d (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold) based on EcNo measurements..
gsmThresh3a: Threshold for event 3a (the estimated quality of the currently used WCDMA RAN frequency is below a certain threshold and the estimated quality of the GSM system is above a
certain threshold) for GSM.
gsmPropRepeatInterval: Minimum time interval between proposals of the same GSM cell for handover based on the same measurement report.
gsmAmountPropRepeat: Maximum number of repeated proposals (not including the first proposal) of GSM cells for handover based on the same measurement report.
Idle Mode (Selection/ Reselection)
qQualMin: Minimum required quality level in the cell measured in the UE.
qRxLevMin: Parameter that indicates the min. required signal strength in the cell
qualMeasQuantity: Used for decision as to whether the 3G ranking for cell selection and reselection is based on EcNo or RSCP. Default is EcNo.
qHyst1: Hysteresis values used for serving cell, when ranking is based on CPICH RSCP
qHyst2: Hysteresis values used for serving cell, when ranking is based on CPICH EcNo
qOffset1sn: Signal strength offset b/w source and target cell for cell ranking based on CPICH RSCP.
qOffset2sn: Signal offset between serving cell and neighbor cell, based on CPICH EcNo.
sIntraSearch: Decision on when intra-freq. measurements should be performed. Following criteria is used:
sIntraSearch ≥ qQualmeas - qQualMin (where qQualmeas is the value measured by UE )
sInterSearch: Parameter is used to make decision to start inter-freq. measurements.
sInterSearch ≥ qQualmeas - qQualMin (where qQualmeas is the value measured by UE )
sRatSearch: Decision on when GSM measurement should be performed in relation to qQualMin.
sRatSearch ≥ qQualMeas – qQualMin (where qQualmeas is the value measured by UE )
sHcsRatSearch: Decision on when GSM measurement should be performed in relation to qRxLevMin.
sHcsRatSearch ≥ qRxLevMeas – qRxLevMin (where qRxLevMeas is the value measured by UE)
Comparison of parameters between some RNCs
•
•
•
•
>amos -m RNCE1, RNCE2, RNCE3
>lt rncfunction
>get rncfunction (to find the proxy)
>diff 125285 125284
Restart Ranks, cont
Data in own memory
segment
Domain
Preserved
Cleared
4
Conditional
Cleared
Cleared
1, 2, 3, 4
Yes
Cleared
Cleared
1, 2
Rank
T&E logs
HW test
HW reset
SW reload
Hot
Preserved
No
No
Conditional
Warm
Preserved
No
No
Yes on MP/BP
Not necessarily on
FPGA/DSP/etc.
Data in CLI
container
Refresh
Preserved
No
Cold
Cleared
Limited
Yes
Yes
Cleared
Cleared
1, 2, 3
ColdWTest
Cleared
Yes
Yes
Yes
Cleared
Cleared
1, 2, 3
Restart commands from MO interface
RNCSM01> acc 0 manualrestart
Call Action manualrestart on following MOs ?
===============================================================================
0 ManagedElement=1
===============================================================================
Are you Sure [y/n] ? y
===============================================================================
Proxy MO
Action
Nr of Params
===============================================================================
0 ManagedElement=1 manualRestart
3
Parameter 1 of 3, restartRank (enumRef-RestartRank):
Enter one of the following integers: 0:RESTART_WARM, 1:RESTART_REFRESH, 2:RESTART_COLD,
3:RESTART_COLDWTEST: 0
Parameter 2 of 3, restartReason (enumRef-RestartReason):
Enter one of the following integers: 0:PLANNED_RECONFIGURATION, 1:UNPLANNED_NODE_EXTERNAL_PROBLEMS,
2:UNPLANNED_NODE_UPGRADE_PROBLEMS, 3:UNPLANNED_O_AND_M_ISSUE,
4:UNPLANNED_CYCLIC_RECOVERY, 5:UNPLANNED_LOCKED_RESOURCES, 6:UNPLANNED_COLD_WITH_HW_TEST,
7:UNPLANNED_CALL_PROCESSING_DEGRADATION, 8:UNPLANNED_LOW_COVERAGE: 0
Parameter 3 of 3, restartInfo (string): eanzmagn
>>> Return value = null
===============================================================================
Total: 1 MOs attempted, 1 MOs actioned
Restart commands from MO interface
Board restart using the MO LDN
RNCSM01> acc ms,slot=9,pluginunit=1$ manualrestart
...<cut>...
Board restart using a board group
RNCSM01> acc mod1 manualrestart
...<cut>...
Checking Restart Information
RNCSM01> lgvsm
RNCSM01> lgd
!Node restart times!
RNCSM01> lhsh 001400 llog –l!board restarts logs!
RNCSM01> cabr
!all board!
Parameter Audit
RNCSM01> h diff
*******************************************************
diff/ldiff
*******************************************************
....
2) Syntax 2: diff/ldiff <moGroup>|<moFilter>|<proxy>|<modumpFile>|<modumpDir>
[<baselineFile>|<modumpFile2>|default] [<outputDir>]
To compare an MO dump with a parameter baseline file or with another MO dump.
etc.....
From the unix prompt, do:
If one node only:
moshell <ipaddress> ‘lt all ; diff . ‘
If many nodes:
mobatch <sitefile> ‘lt all ; diff . ‘
For using another baseline file:
moshell <ipaddress> ‘lt all ; diff . mybaseline.txt‘
If many nodes:
mobatch <sitefile> ‘lt all ; diff . mybaseline.txt‘
Traffic per Cell
See all major KPIs per Site and Per RNC
Active Emergency Lisence
acc Licensing=1 setEmergencyState
(WNCS)
WCDMA Neighboring Cell
Support
Table of Contents
•
•
•
•
Overview
Data Collection
Reports & Analysis
Export Reports
Overview
• WNCS is an optional feature and it is part of the Radio Network
Optimization (RNO) in OSS-RC.
• WNCS feature provides an easy and efficient way to keep the neighbor
relations optimized by
– Identifying missing neighboring cells that should be defined as neighbors.
– Identifying existing defined neighbor relations that can be removed(Optimizers
generally does not use this method)
• WNCS feature can only support neighbor optimization between cells
using the same frequency.
• WNCS feature uses GPEH events to identify missing neighbor relations
and counters to measure the existing defined neighbor relation usage.
Data Collection
• WNCS is part of the RNO and can be access in OSS-RC as shown.
Data Collection
• In RNO -> Select File -> New Recording -> NCS…
1
1.
Name this recording
2.
Select Both GPEH and Counters
3.
Define recording period
Start time should be at least
5 mins before the next ROP.
4.
Select cells to include in this
recording.
5.
Add optional comment to this
recording.
6.
Select Save and Schedule to
schedule this recording.
2
3
5
4
6
Data Collection – Additional Info
• Data to Measure
• There are three choices:
– Both GPEH events and Counters
– Only GPEH events
– Only Counters
• If "Only GPEH events" is selected, then no data for
monitored neighbors will be available in the reports.
(defined neighbor usage % will be missing)
• If "Only Counters" is selected, then no data for missing and
unmonitored neighbors will be available in the reports.
• Recommend to select “Both GPEH events and Counters”.
Reports & Analysis
• NCS Overview Report presents the results of a recording in a table
where the reported scrambling codes are summarized for each cell.
• These results are used to determine which cells have neighbor
relations that can be improved.
• From this report a cell can be selected to be further analyzed in the
cell report.
Reports & Analysis
• The overview report can be used to quickly find the cells that have
the most problems with the neighbor definitions, especially many
missing neighbor detections and drops.
Sort in descending order to identify cells
with high number of events from missing
neighbor. This indicates that the cell has
undefined neighbor cells that should be
defined as neighbors. Consider also the
number of drops when determining the
order of which the cells should be attended
to. Select the cell with most severe
problems and open the NCS Cell Report.
Reports & Analysis
NCS Cell Report presents detailed information about each cell. Double-click on
the cell in the Overview Report to view the Cell Report.
NCS Cell Report
Defined Neighbors
Undefined Neighbors
Find missing neighbor relations
that can be added
Monitored Neighbors
Find neighbor relations
that can be removed
Unmonitored Neighbors
Review the priority status of
cells that appeared as
unmonitored neighbor in the
current neighbor list
Reports & Analysis – Delete Neighbor
Use the Relative Usage column to find defined neighbors that are never used and can be removed.
Before removing a neighbor definition it should be considered if the statistics is enough and covers
different hours and different traffic patterns during the day, and that the cell was operational during
the recording.
Neighbor relations with significant amount of usage combined with a cell distance much larger than
the other neighbors could be the coverage of the target cell overshooting other cells. A monitored
neighbor list showing more than 25 neighbor relations, all with significant amount of usage, is an
indication the source cell being overshooting surrounding cells.
Note that the relative usage consider only speech traffic.
To remove neighbor :
Select the neighbor to be removed and follow the menu selection as shown. This will be
saved in WNCS Change Order.
Reports & Analysis
Defined Neighbor Column Header Descriptions
•
Cell Name
– The cell name of the monitored defined neighbor.
•
Cell User Label
– The cell user label of the monitored defined neighbor.
•
Scrambling Code
– The scrambling code for the monitored defined neighbor.
•
No. of Attempts
– The number of RL addition attempts for this monitored defined neighbor.
•
Success (%)
– The percentage of the RL addition attempts that was successful.
•
Failures (%)
– The percentage of the RL addition attempts that failed.
•
Relative Usage (%)
– The number of attempts for this neighbor compared to number of attempts for all
neighbors for the cell that the report shows.
Reports
&
Analysis
Defined Neighbor Column Header Descriptions
•
Selection Priority
– In order to reduce the number of dropped calls the neighbor cell relations have to be prioritized to avoid unwanted
truncation of best-ranked neighbors (which could happen if the number of defined neighbors are more than
approximately 20). The selection priority property of the neighbor cell relation enables that prioritization, it is used to
rank neighbor cell relations for inclusion in the monitored set.
•
Operational State
– The operational state of the neighbor during the recording periods. The operational state can be active, partly active or
inactive. Active means that the cell has been active in all recording periods. Partly active means that the cell has been
both active and inactive during the recording and switched state between periods. Inactive means that the cell has been
inactive in all recording periods. If the neighbor cell belongs to another OSS the column is empty.
•
Distance (km)
– Distance between the antenna of the measuring cell and the antenna of the defined neighbor in kilometers. The altitude
of the antennas are not considered, only longitude and latitude are used for the distance calculation.
To change priority of a neighbor :
Select the target neighbor and follow the menu selection as shown. A Set Selection Priority
prompt will appear. Enter the new priority number and select OK. This will be saved in WNCS
Change Order.
Reports & Analysis
Unmonitored Neighbor Column Header Descriptions
•
Cell Name
– The cell name of the unmonitored defined neighbor.
•
Cell User Label
– The cell user label of the unmonitored defined neighbor.
•
No. of Detections
– The number of detections for this unmonitored defined neighbor.
•
Selection Priority
– In order to reduce the number of dropped calls the neighbor cell relations have to be prioritized to avoid
unwanted truncation of best-ranked neighbors (which could happen if the number of defined neighbors
are more than approximately 20). The selection priority property of the neighbor cell relation enables that
prioritization, it is used to rank neighbor cell relations for inclusion in the monitored set.
•
Operational State
– The operational state of the neighbor during the recording periods. The operational state can be active,
partly active or inactive. Active means that the cell has been active in all recording periods. Partly active
means that the cell has been both active and inactive during the recording and switched state between
periods. Inactive means that the cell has been inactive in all recording periods. If the neighbor cell belongs
to another OSS the column is empty.
•
Distance (km)
– Distance between the antenna of the measuring cell and the antenna of the defined neighbor in
kilometers. The altitude of the antennas are not considered, only longitude and latitude are used for the
distance calculation.
Reports & Analysis – Add Neighbor
1. Sort in descending order to identify the highest number of missing
events from missing neighbor candidate.
2. Taken into considering also the number of drops.
3. Check the neighbor candidate in the NCS Probable Cell Name
Diagnostics Report to evaluate the risk of mixed up cell names. Also use
the distance information to determine the most probable cell. (It is
therefore important to have the correct latitude and longitude coordinates configured in the RBS and must be configured for all cells)
4. Add neighbor candidate after its identity is confirmed and should be
added as neighbor.
To add a neighbor :
Select the neighbor to add and follow the menu selection as shown. A Set Selection
Priority prompt will appear. Assign a priority number for the new neighbor and select OK.
This will be saved in WNCS Change Order.
Reports & Analysis
Undefined Neighbor Column Header Descriptions
•
Probable Cell Name
– The probable cell name of the missing neighbor.
•
Scrambling Code
– The scrambling code for the missing neighbor.
•
No. of Possible RL Add. Att.
– The number of possible RL addition attempts for this missing neighbor.
•
No. of Missing Events
– The number of missing events for this missing neighbor.
•
No. of Drops
– The number of drops.
•
Time in Active Set (min)
– The time (in minutes) that this missing neighbors could have been in the active set.
•
Average RSCP (dBm)
– Average Received Signal Code Power (RSCP) for the cell that triggered the measurement report.
•
Average Ec/No (dB)
– Average received energy per chip divided by the power density of the band (noise) for the cell that
triggered the measurement report.
Export Reports
• Another method is to export the results and analyze the data using Excel instead of doing it in
OSS.
• Select the recording you wanted to analyze. Select File -> Export -> Tab Separated Files
• Exported file will be saved in this location, /var/opt/ericsson/wncs/data/export/
Export Reports
 Analyze the report in Excel.
(MRR-W)
Measurement Result Recording for
WCDMA
Overview
•
•
MRR-W (Measurement Result Recording for WCDMA) is an useful feature to evaluate
and monitor network performance and quality, especially in network tuning and
optimization project activities.
MRR-W collects statistics from UE, RBS, and RNC, it’s performed for different services
and measurement quantities.
- measurements period
- selected cells
- combination of services and
measurement quantities (RNC)
- spreading factor chosen (RBS)
UE & RNC Meas
MRR-W activation at RNO:
DL BLER
UL BLER
stored at
RNC xml
files
Ue Tx Power
DL CPICH EcNo
DL CPICH RSCP
RBS
DL Tx Code Power
stored at
RBS xml
files
Overview
•
The following services and RAB are supported:
– Speech12200 Speech Narrow Band 12.2.
– AMR4750 Speech AMR NB 4.75.
– AMR5900 Speech AMR NB 5.9.
– AMR7950 Speech AMR NB 7.95.
– AMRWB Speech AMR Wide Band.
– Video Includes RAB configurations with CS64, also together with low rate PS interactive
connections.
– PSINTDCHDCH Includes PS Interactive RAB configurations with supported UL and DL rates on DCH.
– PSINTDCHHS Includes PS interactive RAB configurations with supported rates on DCH in UL and
HSDPA in DL.
– PSINTEULHS Includes PS Interactive RAB configurations on EUL/HS.
– PSSTRDCHHS Includes PS Streaming RAB configurations with supported rates on DCH in UL and
HSDPA in DL.
– PSSTRDCHDCH Includes PS Streaming RAB configurations with supported rates on DCH.
– Speech12200_ALL Includes multi-RAB configurations with Speech NB 12.2 together with
Interactive and Streaming RABs on both DCH and HS. Note that BLER measurements are
performed for the speech part.
– AMRWB_ALL Includes multi-RAB configurations with Speech WB together with Interactive and
Streaming RABs on both DCH and HS. Note that BLER measurements are performed for the speech
part.
– CSStreaming CS Streaming 57.6 on DCH.
– PSSTRDCHHS_ALL Includes PS Streaming RAB configurations with supported rates on DCH in UL
and HSDPA in DL, together with PS interactive RABs on DCH and HS.
– AMRNBMM Speech AMR Narrow Band Multimode.
– AMRNBMM_ALL Includes multiRAB configurations with Speech AMR Narrow Band Multimode
together with PS interactive RABs on DCH and HS.
Data Collection
• MRR-W is part of the RNO and can be access in
OSS-RC as shown.
Data Collection
Create recording name &
recording periods
Select recording cells
Save & Schedule
when completed
Select service & the
quantity to be included
in the recording. (see
next slide for details)
Data Collection
1. Select “P7MD or earlier” for RAN
P7.0.3
2. Allows up to 6 Service and
measurement quantity per cell. For
P7FP or later, the allowance is
maximum of 12.
3. Set the sampling periods and the UE
fraction. (details in next slide)
4. Select DL Tx Code Power per SF to be
included in the recording (if required).
•
•
•
•
The sample periods for the periodic measurements can be set between 2
and 64 seconds, separately for speech, video, streaming and interactive,
which then also applies to the corresponding multi-RAB combinations.
For the UE measurements this is the interval with which the UE is ordered
to send periodic measurement reports.
The UE fraction can be set to the values FULL, 1/2, 1/3, 1/4 and 1/5, which
has the effect of including this fraction of the users in the recording.
The UE fraction can be used to reduce the load and scope of the
recording, and is primarily intended to be used when high sample rates
are required.
Reporting
• Through RNO main window in OSS.
Double-click on selected MRR-W
report to access Overview Report.
Reporting
• MRR-W Overview Report contains a summary of the recording
results.
10.34% of the samples for cell
UT0616YA1 has Ec/No worst
than -12dB
2.44% of the samples for cell
UT1033XB2 has RSCP< -100dBm
Reporting
• The MRR-W cell histogram displays the actual detailed measurement
results for each cell, in the form of pdf distributions.
• These histograms can be used for detailed analysis of the quality and
radio environment for each cell.
Results obtained with MRR-W
Statistical radio measurements per cell.
• Cells properly tuned have:
–
–
–
–
Most UEs with low TX Power.
Most UEs have good Ec/No.
Most UEs have good RSCP.
BLER is according to target for service.
Results obtained with MRR-W
Statistical radio measurements per cell - TxPower.
“Uplink Coverage” of a particular cell.
As it can be obtained per service, one can
see if a particular service:
– runs out of power
– has a coverage that has shrunk.
“Downlink Coverage” of a particular cell.
It can be obtained per Spreading Factor,
which is related to services. One can see if a
particular SF (or even service):
– runs out of power
– has a coverage that has shrunk.
Results obtained with MRR-W
Statistical radio measurements per cell - BLER.
Downlink quality of a particular cell
Uplink quality of a particular cell
It can be obtained per services, separately:
– Speech needs a very low BLER
Results obtained with MRR-W
Statistical radio measurements per cell - CPICH.
CPICH Ec/No
(“interference in the cell”)
CPICH RSCP
(“signal strength, pathloss”)
CPICH to identify coverage problems:
CPICH RSCP
Very weak: why?
- Lack of coverage.
- Lots of indoor traffic.
- Handover problem. IRAT/IF HO problem.
- Cell overshooting.
FFAx-W
Find Faulty Antenna Expert for
WCDMA
Find Faulty Antenna Expert for WCDMA
• This presentation contains a summary about
OSS-RC feature Find Faulty Antenna Expert
for WCDMA, and instructions how to start
FFAX-W and a few problem identification
examples.
Find Faulty Antenna Expert for WCDMA
Summary
• FFAX-W can be used for remote antenna problem
identification. With FFAX-W, it is possible to measure
the performance of the antenna system at every sector.
• The data is collected from the antenna receiver
branches in RBS and is processed in OSS-RC, thereby
enabling the system to identify poorly performing
antenna installations as well as providing an indication
of the type of fault.
Find Faulty Antenna Expert for WCDMA
Benefits

Antenna systems that perform below their optimum are detected

Data is collected with an absolute minimum of effort as well as very quickly for an entire network avoiding costly drive tests
or other type of on site investigations

Cost efficient way of finding faulty antenna installations

Reduction of the time needed between problem detection and correction. The FFAX-W enables operators to send personnel
on site with knowledge of what needs to de fixed.

Antenna systems that perform below their optimum are detected

The system can benefit fully from the functionalities receiver diversity, transmitter diversity and MIMO

Data is collected with an absolute minimum of effort as well as very quickly for an entire network avoiding costly drive tests
or other type of on site investigations

Reduction of the time needed between problem detection and correction (e.g. same day depending on site location). The
feature enables operators to send personnel on site with knowledge of what needs to be fixed

More efficient acceptance procedure for operators if third party resources are used for e.g. installation or site maintenance

Areas which suffer from e.g. storms or hurricanes can be monitored proactively
Find Faulty Antenna Expert for WCDMA
Short theory how FFAX-W works
• RBS measurements:
– Radio Base Station (RBS) measures the difference in SIR per receive branch as pdf
counters, pmBranchDeltaSir.
• Data is fed to OSS-RC for analysis:
– Difference between two diversity branches should be small, but in case the
difference is significant or the variation is larger than expected, this is a strong
indication that at least one of the antenna branches is not performing optimally.
FFAX-W: pmBranchDeltaSir
pmBranchDeltaSir
The difference in SIR per receive branch per connection (DPCCH) per cell. The purpose with the measurement is to detect faulty feeder
installations.
Counter type: PDF
Counter is reset after measurement interval: Yes
Condition: One measurement every 1000 ms. The actual measurement will start on all enabled UBCH device set. Only valid measurement
values will be used in the pm-counters. If there is no signal on any branch the difference in SIR is excluded.
PDF ranges:
[0]: Value : SIR sample in range =< -29.5 dB
[1]: Value : SIR sample in range [-29.5 .. -28.5[ dB
[2]: Value : SIR sample in range [-28.5 .. -27.5[ dB
...
[29]: Value : SIR sample in range [-1.5 .. -0.5[ dB
[30]: Value : SIR sample in range [-0.5 .. 0.5[ dB
[31]: Value : SIR sample in range [0.5 .. 1.5[ dB
...
[58]: Value : SIR sample in range [27.5 .. 28.5[ dB
[59]: Value : SIR sample in range [28.5 .. 29.5[ dB
[60]: Value : SIR sample in range >= 29.5 dB
Undefined value: -1
MaxLength=61
FFAX-W problem identification
• FFAX-W can indicate the following states based on SIR
measurement:
1. Normal – no failure
2. Losses in RF path
3. Antenna diagram mismatch
4. Swapped Feeder
5. Missing feeder
PROCEDURE TO VERIFY FFAX-W OVERVIEW REPORTS IN RNO
2.
Losses in RF path
Condition: “Average SIR Difference” should be more than 3 dB and “Standard Deviation SIR Difference” should be less than (average-3) + 5 dB
3.
Swapped feeder
Condition: “Standard Deviation SIR Difference” should be more than 10 dB
4.
Missing Feeder
Condition: “Average SIR Difference” should be 29.5 or -29.5.
5.
Antenna Diagram Mismatch
Condition: “Average SIR Difference” should be greater than 3dB and “Standard Deviation SIR Difference” should be greater than or equal to (Average SIR Difference
-3)/8.
Problem identification
SIR difference indicates potential problem
SIR diff
-29.5
+29.5
SIR diff
-29.5
Losses in RF path
-29.5
+29.5
* Average SIR difference > 3 dB
* Std dev > (average-3)+5 dB
-29.5
+29.5
* Average SIR difference = 29.5 or -29.5
Antenna diagram mismatch
+29.5
* Average SIR difference > 3 dB
* Std dev < (average-3) + 5 dB
+29.5
* Std dev > 10 dB
* Average SIR difference < 3 dB
* Std dev < 10 dB
-29.5
Missing feeder
Swapped Feeder
Normal (no failure)
FFAX-W recording
1. Open Radio Network
Optimization (RNO)
FFAX-W recording
2. In RNO select New Recording and FFAX-W…
FFAX-W recording
3. Give a Recording name.
4. Select recording periods and start date.
5. Select how many times recording will be
repeated.
FFAX-W recording
6. Select Cells or
Cell Sets, and press
OK.
FFAX-W recording
7. Start recording, press Save and Schedule.
FFAX-W problem identification
When recording is completed in RNO, double click it and FFAX-W Overview Report window will
open.
problem identification
No fault
By double clicking Cell Name in
Report, FAXX-W Cell Histogram
window will open.
Average difference < B dB
Std deviation < A dB
1.08 < 3
6.15 < 10
problem identification
losses in rf path
Average difference > B dB
Std < ((average-B)/C + D)
13.01 > 3
6.66 < ((13.01 – 3)/3 + 5)
problem identification
missing feeder
* Average SIR difference = 26.28
problem identification
antenna diagram mismatch
Antenna diagram mismatch:
Average difference > B dB
Std deviation >= ((average-B)/C + D)
4.06 > 3
6.64 >= ((4.06 – 3)/3 + 5)
problem identification
SWAPPED feeder
Example from Swapped Feeders:
Standard deviation > A dB
16.63 > 10
USING Bussiness objects for result analysis
CONCLUSIONS
• The required number of samples in a cell is minimum 3000, cells with lower number of samples should
be taken out of the analysis.
• Due to the relatively low traffic, at least four-five hour recording time was needed to obtain adequate
data.
• It is recommended to make two-three consecutive recordings in order to securely identify a faulty cell.
• Periodic evaluation of the performance is needed. Each month, Operator should repeat FFAX
measurement.
• After natural events FFAX should be scheduled. For example;
–
–
–
–
Rain
Wind
Earthquake
Sand
•
•
•
•
•
RNC>get site servicearea (to see LAC and CI)
RNC>get site routingarea (to see RAC)
Site>st nba (NBAP must be enable for getting traffic
Site>get sync
Site>get .hsdpacap