ZTE GERAN Counters & KPIs
ZTE University
Objectives

At the end of this course, you will be able to:



Master ZTE traffic statistic function
Understand the meaning of common-used traffic
statistic indices
Master the methods to analyze and locate the network
problems by the way of traffic statistic analysis
Contents

Overview of traffic statistic
 Traffic statistic KPI
 Locate and analyze network problems
 Traffic statistic analysis instance
Introduction of ZTE traffic statistic
Traffic
statistic
Alarm
statistic
Performance
index
Measurement
statistic
CS traffic
measurement
PS traffic
measurement
KPI of CS traffic statistic

Primal indices










SDCCH congestion rate
SDCCH assignment success
rate
SDCCH call drop rate
TCH congestion rate
TCH assignment success rate
TCH call drop rate
Handover success rate
Random access success rate
Paging success rate
Integrated indices




Traffic call drop rate
Bad cell rate
TCH allocation rate
Radio access success rate
KPI of PS traffic statistic

TBF








UL TBF Establishment Success Rate
DL TBF Establishment Success Rate
UL Signaling TBF Failure Rate
DL Signaling TBF Failure Rate
UL GPRS Data TBF Failure Rate
DL GPRS Data TBF Failure Rate
UL EDGE Data TBF Failure Rate
DL EDGE Data TBF Failure Rate
KPI of PS traffic statistic

LLC




DL LLC Signaling Frame Discard Rate
DL LLC GPRS Data Frame Discard Rate
DL LLC EDGE Data Frame Discard Rate
Throughput




UL GPRS Throughput
DL GPRS Throughput
UL EDGE Throughput
DL EDGE Throughput
CS traffic measurement
Assignment Measurement
1
Assignment counter describers the assignment process. As many
attempts can be made if no channel is available in the first assignment
attempt, it is necessary to make a completed description of the whole
assignment process instead of the assignment processes of TCH/F or
TCH/H. These counters are used to analyze influences of forced
release, queuing and directed retry, to assignment success rate from
the viewpoint of calling.
CS traffic measurement
Handover cause measurement
2
Handover cause counter is used for checking MS handover causes.
According to cell radio environment and BSC settings, handover
algorithm judgment module can carry out handover due to several
different handover causes, so as to realize functions such as
optimizing resource usage, improving call quality and rescuing calls.
CS traffic measurement
Call drop measurement
3
Channels that take part in the measurement statistic include SDCCH,
TCH/F and TCH/H. Service types include signaling, voice and data.
Counted call drop causes include RMM losses contact with SMM,
BTS radio link failure, LAPD link failure, OMCR forced release, forced
release by other calls, handover failure, as well as other failure.
CS traffic measurement
Radio resource available measurement
4
Radio resource available measurement counters count the number,
mean number and the maximum busy number of available SDCCH,
TCH/H and TCH/F, as well as total busy and congestion time of these
channels in the cell.
CS traffic measurement
General handover measurement
5
General handover counter is used to find out MS handover successes,
failures, and frequency of abnormal events during handover. After
configured with inter-system handover or concentric circle, general
handover counter is also used to find out inter-cell traffic sharing to
improve the wireless planning.
CS traffic measurement
Adjacent cell handover measurement
6
Adjacent cell handover counter is used to record the number of
outgoing handover or incoming handover so as to find out the
handover between the cell and its adjacent cell which lays a basis for
configuration of adjacent cell and improves service quality of the cell
through handover.
CS traffic measurement
Radio access measurement
7

Radio access counter is mainly used to observe MS radio random
access process as the reference of radio access parameter
adjustment, signaling channel allocation strategy, etc. Several
possible causes of radio access are listed here. Access statistics
related to GPRS is not listed here but in the category of other access
request temporarily.
 The number of access request is that of receiving “Channel Required”
message; the number of successful access process is that of sending
“Immediate Assignment” message.
CS traffic measurement
Radio measurement
8
Radio measurement items mainly include UL/DL quality, signal
strength, TA, interference band and RQ value of radio channels. The
UL/DL quality, signal strength, TA and RQ value are counted after
measurement report or pre-processing measurement report sent by
BTS is received; BSC updates interference band status in database
after receiving measurement report or pre-processing measurement
report. The value of interference band can be inquired in database
when periodical measurement is reported.
CS traffic measurement
Sub cell statistics
9
Sub cell statistics counter is used to find out operation status of the sub
cell in radio environment. It focuses on inter-sub-cell handover and
relevant counting at the second sub cell so as to check traffic
absorption condition by the second sub cell.
CS traffic measurement
MS TA measurement
10
MS TA counters are used to check the value of TA in MS measurement
reports. TA can reflect the relative location of MS in the cell. If most of
the TAs are in very high level, network planning should be remade,
such as, increasing the site density.
CS traffic measurement
SAPI3 measurement
11
MO-SM is short message of mobile originating call; MT-SM is short
messages of mobile terminating call. In conversation status, the MS
can receive point-to-point message so the mobile caller maybe the
other side of receiving short message at one time. On the wireless
side, short message could be transmitted by the following five
channels: SACCH/F, SACCH/H, SDCCH, FACCHF and FACCHH. So
far the statistics counting has been realized by the channel of
SACCH/F, SACCH/H and SDCCH.
CS traffic measurement
TRX measurement
12
TRX measurement is to measure the success or failure condition of
channel activation, assignment, and handover in the unit of carrier. It
also can measure carrier interference band, maximum and minimum
UL & DL level condition, to learn the status of different carriers,
providing evidence for adjustment and maintenance.
CS traffic measurement
Timeslot measurement
13
Timeslot counters are used to view the radio transceiver environment
of a MS in a particular timeslot, including the link quality and strength
in the timeslot. These data is sent to Network side through
measurement report. If signal strength in some timeslots is weak, then
it can be improved by changing send and receive power.
CS traffic measurement
SDCCH measurement
14
SDCCH counters describe allocation, occupation, assignment, use of
resources related to SDCCH, which as SDCCH configuration and
parameters adjustment basis. Allocation of SDCCH is mainly in the
process of immediate assignment and handover. Handover includes
internal and external handover. The statistic unit in this measurement
is cell.
CS traffic measurement
TCH/F measurement & TCH/H measurement
15
In GSM BSC signaling system, allocation and usage of TCH/F(TCH/H)
channel mainly exist in assignment and handover flow, where
assignment flow includes immediate assignment and common
assignment; handover flow includes internal and external handover.
CS traffic measurement
Abis interface message counter measurement
16
Abis interface message measurement is mainly for all kinds of
messages of Abis interface to count. It is convenient to find out the
frequency of all kinds of messages transmitting on Abis interface.
When BSC receives the messages sent by BTS, the counter begin to
count.
CS traffic measurement
17
BTS TRX measurement

According to the receiving level and receiving quality in MS
measurement report and the receiving level and receiving quality in
BTS measurement, BTS decides whether to perform power control for
MS or BTS. BTS also performs statistics according to different
reasons for power control.
 There are two ways for power control: common control and rapid
control. The power control amplitude in rapid control is larger than that
in common control. Besides, BTS periodically samples the power of
MS and BTS to get the average power.
 After the power control measurement task is customized, BTS
periodically reports the power control statistic result to BSC through
the PC TEST RPT message. The power control measurement result
can be used to analyze coverage quality and power control effect and
frequency.
CS traffic measurement
BSSMAP message measurement
18
The BSSMAP message measurement performs statistics for various
BSSMAP messages at A-interface. It is used to find out the frequency
of various BSSMAP messages transmitted at A-interface. When BSC
receives the correct BSSMAP message from MSC, the counter counts.
CS traffic measurement
A-Interface message measurement
19
The A-interface message measurement performs statistics for
uplink/downlink DTAP message, BSSMAP message, and received
incorrect BSSMAP message. Statistic unit in this measurement is
CMP.
CS traffic measurement
Ater message measurement
20
Ater interface message counters are used to collect statistics on
messages transceived on Ater interface. It is counted by AterDispatch
according to iTC office.
PS traffic measurement
Downlink data TBF measurement
1

DL TBF process comprises establishment, transmission and release
of the DL TBF.
 The establishment includes the DL TBF establishment on CCCH,
PCCCH and PACCH.
 The release includes normal release and abnormal release of the DL
TBF. Abnormal release is used to judge the running of PS service so
as to make adjustment.
 DL transmission measurement mainly focuses on the connecting time
of the DL TBF and the number of co-existing DL TBFs.
PS traffic measurement
Uplink data TBF measurement
2
Uplink (UL) data TBF measurement mainly involves processes of
establishing TBF, keeping TBF and releasing TBF on cells.
PS traffic measurement
Data flow measurement
3
Data flow measurement focuses on the flow related information,
including the LLC frames, RLC blocks and TBF connecting time.
PS traffic measurement
Uplink/Downlink RLC statistic measurement
4

RLC blocks are classified into control block and data block based on
the content. Data block includes RLC block waiting to be
acknowledged (Pending block), retransmitted block (NACK block),
and first-transmitted block (new blocks excluding retransmitted RLC
block and pending RLC blocks).
 RLC coding scheme includes CS1 ~ CS4 and MCS1 ~ MCS9. Coding
scheme is set at background and can be adjusted by BSC according
to the link quality.
 UL/DL RLC statistics is used to find out the number of RLC blocks
with different coding schemes received and sent by BSC as well as
coding scheme adjustment times during transmission process.
PS traffic measurement
PS resource used statistic measurement
5
Statistic counters are used to measure the PS resource usage in each
cell, including number of usable PS channels, average and max
number of busy PS channels, total busy time of PS channels, total
time of PS channel congestion and using of PS channels.
PS traffic measurement
Uplink and Downlink PACCH statistics
6
In transmitting GPRS data service, UL and DL PACCH statistics is
used to count the number of receiving and sending controlled
messages on PACCH, including packet access reject, packet
resource request, packet UL assignment, etc.
PS traffic measurement
Downlink GPRS data TBF statistics
7
DL GPRS data TBF statistics is used to observe the process of GPRS
DL TBF establishment, maintenance and release.
8
Downlink EGPRS data TBF statistics
DL EGPRS data TBF statistics is used to observe the process of
EGPRS DL TBF establishment, maintenance and release.
PS traffic measurement
Uplink GPRS data TBF statistics
9
UL GPRS data TBF statistics collects the information about the
establishment, maintain and release of UL GPRS TBF.
10
Uplink EGPRS data TBF statistics
UL EGPRS data TBF statistics collects the information about the
establishment, maintain and release of UL EGPRS TBF.
PS traffic measurement
BSSGP flow statistic
11
BSSGP flow statistics mainly measures the message
transmission condition at Gb BSSGP level in GPRS service, to
count different signaling messages. This includes the number
of packet paging, circuit paging, BVC block, BVC unblock, BVC
reset, location request, and location result response, etc.
PS traffic measurement
Gb message statistics (BVC cell)
12
Gb message statistics mainly measures transmission number of
different PTP messages at Gb BSSGP level in GPRS service (such as
RA-CAPABILITY, RADIO-STATUS, DOWNLOAD-BSS-PFC).
PS traffic measurement
NSVC statistic measurement
13
The NSVC statistic measurement is used to measure signaling
interaction and data transmission at NS layer of Gb interface for
GPRS service. It counts the number of various messages, such as
blocking, unblocking, resetting, and ALIVE.
PS traffic measurement
NSE statistic measurement
14
The NSE statistic measurement takes a single NSE as the
measurement entity. It performs statistics for paging message, status
indication message, and signaling BVC resetting message received
by NSE at BSS.
PS traffic measurement
NSVC on IPGB HOST measurement
15
The NSVC statistic measurement on IPGB HOST is used to measure
signaling interaction and data transmission at NS layer of Gb interface
in GPRS service. It also performs statistics for abnormalities in
various flows.
PS traffic measurement
GB Message on IPGB HOST measurement
16
The Gb interface message measurement on IPGB HOST measures
the number of transceiving various PTP messages at BSSGP layer of
Gb interface in GPRS service, such as RA-CAPABILITY, RADIOSTATUS, and DOWNLOAD-BSS-PFC.
PS traffic measurement
NSE on IPGB HOST measurement
17
The NSE measurement on IPGB HOST takes a single NSE as the
measurement entity. It performs statistics for paging message, status
indication message, and signaling BVC resetting message received
by NSE at BSS.
Contents

Overview of traffic statistic
 Traffic statistic KPI
 Locate and analyze network problems
 Traffic statistic analysis instance
SDCCH measurement point
MS
BTS
BSC
CHL_REQ
CHL_RQD
A1
CHL_ACT
A2
CHL_ACT_ACK
IMM_ASS_CMD
IMM_ASS
A3
SABM
EST_IND
A4
T3101
Time out
SDCCH Counters

SDCCH
Total call
attempts
SDCCH
Total
overflows
All the requests for SDCCH channels, including all instances need to
request for a SDCCH such as a normal call origination, location update,
call re-establishment, IMSI request, IMSI detach and SMS.

SDCCH Total call attempts :C900060003+C900060010+C900060038

Check point： A1

All the unsuccessful requests for SDCCH channels because there is no
radio resource.

SDCCH Total overflows:
C900060005+C900060011+C900060039

Check point：A2
SDCCH Counters

ＳＤＣＣＨ
Assignment
attempts
BSC transmit IMM_ASS message to MS for assigning SDCCH,
including assignment success times and failure times.

SDCCH assignment attempts= C900060241

Check point：A3
Number
ＳＤＣＣＨ
Assignment
success
of BSC transmit IMM_ASS, MS successfully access
corresponding SDCCH,BSC received correct EST_IND or
ASSIGN_COM message.
SDCCH Assignment
Check
point: A4
success numbers: C900060242
SDCCH Counters
ＳＤＣＣＨ
Call drop
ＳＤＣＣＨ
Total
traffic

Number of the failed calls in SDCCH before TCH is occupied

SDCCH Call drop: C900060053

Check point： After BSC received correct EST_IND or
ASSIGN_COM message. Before TCH assignment complete
The
total traffic of each SDCCH in busy hours
Total
traffic = SDCCH busy time (C900060124) / statistic
duration
Commonly used KPI

SDCCH Congestion rate
SDCCH congestion rate(%)
=SDCCH overflows/SDCCH call attempts × 100
= (C900060005+C900060011+C900060039)
/(C900060003+C900060010+C900060038 ) × 100


SDCCH assignment success rate
SDCCH assignment success rate (%)
＝SDCCH assignment success/ SDCCH assignment
attempts×100
=C900060242/C900060241× 100

Commonly used KPI

SDCCH call drop rate
SDCCH call drop rate (%)
= SDCCH call drop number/ SDCCH assignment
success number× 100
=C900060053/
(C900060003+C900060010+C900060038 ) × 100

TCH congestion statistic point
BTS
BSC
MSC
ASS_CMD
B1
B2
CHL_ACT
CHL_ACT_ACK
BTS
BSC
MSC
HO_REQ
C1
C2
CHL_ACT
CHL_ACT_ACK
TCH Counters

TCH call
attempts（
exclude
handover）

All the requests for TCH channels, including the calling attempts and
called attempts, and when TCH is assigned as SDCCH in abnormal early
allocation, not including handover .
TCH attempt numbers (exclude handover)
= TCH/F attempts (voice、data) + TCH/H attempts (voice、data)
=C900060019+C900060030+C900060042+C900060046

Check point：B1
 All
TCH overflow
(exclude
handover)
the unsuccessful occupation for TCH because of no radio resource
 Total
TCH overflows (exclude handover)
=TCH/F occupation failure (voice、data) + TCH/H occupation failure
(voice、data) =C900060020+C900060031+C900060043+C900060047
Check point：B2
TCH Counters
 All
the requests for TCH channels, including the calling attempts and
called attempts, handover.
TCH call
attempts
（include
handover)

TCH attempt numbers (include handover)= TCH/F attempts (voice、data)
+ TCH/H attempts (voice、data)
=C900060019+C900060030+C900060042+C900060046+C900060021
+C900060032+C900060044+C900060048
TCH overflow
(include
handover)

Check point：B1+C1

All the unsuccessful occupation for TCH because of no radio resource
 Total
TCH overflows (include handover)=TCH/F occupation failure (voice、
data) + TCH/H occupation failure (voice、data)
= C900060020+C900060031+C900060043+C900060047+
C900060022+C900060033+C900060045+C900060049
 Check
point：B2+C2
TCH Assignment statistic point
TCH Counters
 All
TCH Assignment
attempts
(exclude
handover)
the assignment command after successful TCH occupation
 TCH
assignment attempts =TCH assignment success + TCH assignment
failure=C900060017+C900060028+C900060036+C900060235+C90006
0199+C900060210+C900060018+C900060029+C900060037+C900060
135+C900060200+C900060211
 Check
TCH Assignment
success
(exclude
handover)
point：D1

Numbers of receiving Establish Indication or Assignment Complete
messages after TCH channel is successfully occupied.

TCH assignment success =
C900060017+C900060028+C900060036+C900060235+C900060199+C9
00060210

Check point：D2
Commonly used KPI

TCH congestion rate


TCH congestion rate (exclude handover) = TCH overflows
(exclude handover) / TCH attempts (exclude handover) × 100 =
(C900060020+C900060031+C900060043+C900060047)/(C9000
60019+C900060030+C900060042+C900060046) × 100
TCH congestion rate (include handover) = TCH overflows
(include handover) / TCH attempts (include handover) × 100=
(C900060020+C900060031+C900060043+C900060047+
C900060022+C900060033+C900060045+C900060049)/(C90006
0019+C900060030+C900060042+C900060046+
C900060021+C900060032+C900060044+C900060048) × 100
Commonly used KPI

TCH assignment success rate
TCH assignment success rate =TCH assignment success
number（exclude handover）/ TCH assignment attempts
number（exclude handover）×100
=(C900060017+C900060028+C900060036+C900060235+C9
00060199+C900060210)/(C900060017+C900060028+C90
0060036+C900060235+C900060199+C900060210+C9000
60018+C900060029+C900060037+C900060135+C900060
200+C900060211)×100

Commonly used KPI

TCH call drop rate


TCH call drop rate（include handover）= TCH
call drop number / Total number TCH assignment
success（include handover）×100
Trigger point：Monitor CLEAR REQUEST after
receiving ASSIGMENT COMPLETE message
Commonly used KPI

Handover success rate (Incoming handover)

Handover success rate（%）= （Number of
handover success / number of handover request）
× 100 =
(C900060098+C900060102+C900060120+C900
060094+C900060096)
/(C900060097+C900060099+C900060100+C900
060101+C900060216+C900060119+C90006009
3+C900060095) × 100
Commonly used KPI

Traffic



The total traffic of all TCH, including TCH/F and
TCH/H.
Total TCH traffic = Total busy time of TCH/
statistic duration =
(C900060129+C900060127)/3600
Traffic call drop raito


Total TCH traffic × 60/ total call drop numbers
Unit: minute，represent the average time
separation of every two call drops
Commonly used KPI

Bad cell ratio


Number of bad cells / total number of cells× 100%
Condition:


Busy hours traffic per TCH>0.1Erl，and TCH call drop
rate>3％ or TCH congestion rate>5％
Confirm cell numbers according to average per TCH traffic
>0.1Erl
TCH call drop statistic point

Radio link timeout call drop
MS
BTS
BSC
MSC
Measurement report(SACCH)
Measurement report(SACCH)
Measurement report(SACCH)
Radio link timeout
Connection Failure
Indication
Start T3109
Clear request
Stop T3109
F1
Clear Command
RF Channel Release
RF Channel Release
ACK
Clear Complete
TCH call drop statistic point

Intra cell handover call drop
MS
BTS:TRX
BSC
MSC
CHANNEL ACTIVATE
CHANNEL ACTIVATE ACK
ASSIGNMENT COMMAND
SET T3107
T3107 Timeout
Clear Request
G1
TCH call drop statistic point

Intra BSC handover call drop
MS
Old BTS:
New BTS
BSC
MSC
CHANNEL ACT
CHANNEL ACT ACK
HO_Command
HO_Command
SET T3103
T3103 Timeout
Clear request
H1
TCH call drop statistic point

Inter BSC handover call drop
MS
Old BTS
Old BSC
MSC
New BTS
New BSC
HANDOVER REQUIRED
CHL_ACT
CHL_ACT_ACK
HO_REQ_ACK
HANDOVER COMMAND
HANDOVER COMMAND
HANDOVER COMMAND
SET T8
T8 Timeout
Clear request
I1
TCH Call drop counters
 Total
TCH call
drop number
TCH call drop of all kinds of reasons in current area sub-system .
 Trigger
: Calculate “CLEAR REQUEST” after “ASSIGNMENT COMPLETE”
message and “CLEAR REQUEST” after “HANDOVER COMＭＡＮＤ”
message
 Check
Total TCH
busy hour
traffic
The
point：F1+G1+H1+I1
accumulation of all TCH traffic in busy hour.
Total
TCH traffic = Total TCH busy time/ statistic period
Handover signaling statistic point

Intra cell handover
MS
BTS
BSC
MSC
MEAS_REP
MEAS_RES
CHL_ACT
CHL_ACT_ACK
J1
ASS_CMD
ASS_CMD
SABM
UA
ASS_COM
EST_IND
ASS_COM
J2
HO_PREFORM
Handover signaling statistic point

Intra BSC handover
MS
BTS:Ori_Cell
Measurement Report
BTS:Des_Cell
Measurement Report
BSC:Ori_Cell
BSC:Des_Cell
Handover Algorithm
CHANNEL ACT
CHANNEL ACT ACK
HANDOVER COMMAND
HANDOVER COMPLETE
K1
HANDOVER COMMAND
HANDOVER COMPLETE
HANDOVER COMPLETE
K2
Handover signaling statistic point

Inter BSC handover
MS
Old BTS
Old BSC
MSC
HANDOVER REQUIRED
New BTS
New BSC
HO_REQ
CHL_ACT
CHL_ACT_ACK
HO_REQ_ACK
HANDOVER COMMAND
HANDOVER COMMAND
HANDOVER COMMAND
L1
HO_ACCESS
HO_DETECT
PHY_INFO
SABM
UA
HO_COM
HO_COM
HO_COM
Clear Command
L2
Handover counters

Definitions： Total Incoming handover request numbers, including
Intra-cell, Intra-BSC and inter-BSC handover.
Total
handover
request

Total handover
request:C900060097+C900060099+C900060100+C900060101+
C900060216+C900060119+C900060093+C900060095

Check point：J2+K1+L1

Total
Handover
success
Definitions： Total Incoming handover success numbers,
including Intra-cell, Intra-BSC and inter-BSC handover.

Total handover
success:C900060098+C900060102+C900060120+C900060094+
C900060096
Check
point： J2+K2+L2
UL TBF Establishment Success Rate

UL TBF Establishment Success Rate


This statistic provides UL GPRS signaling TBF,
UL EDGE signaling TBF, UL GPRS data TBF, UL
EDGE data TBF establishment success rate,
which is the important performance index on data
service availability to check the condition of data
access success in different cells.
UL TBF Establishment Success
Rate=(C900040025+C900040033+C900040026+
C900040034)/(C900040159+C900040160+C900
040161+C900040168+C900040163+C90004016
4+C900040165+C900040166)*100
DL TBF Establishment Success Rate

DL TBF Establishment Success Rate


This statistic provides DL GPRS signaling TBF,
DL EDGE signaling TBF, DL GPRS data TBF, DL
EDGE data TBF establishment success rate,
which is the important performance index on data
service availability to check the condition of data
access success in different cells.
DL TBF Establishment Success
Rate=(C900040007+C900040015+C900040008+
C900040016)/(C900040141+C900040142+C900
040143+C900040144+C900040145+C90004014
6+C900040147+C900040148)*100
UL Signaling TBF Failure Rate

UL Signaling TBF Failure Rate


This statistic provides TBF proportion
exceptionally released after UL signaling TBF
establishment success. By this performance
index, it can determine interference, packet loss,
wrong parameter setting, instable link failure may
occur in network.
UL Signaling TBF Failure Rate=(C900040037+
C900040038+ C900040039+ C900040040+
C900040041+ C900040042+ C900040043+
C900040044+ C900040045+
C900040046)/(C900040025+ C900040033)*100
DL Signaling TBF Failure Rate

DL Signaling TBF Failure Rate


This statistic provides TBF proportion
exceptionally released after DL signaling TBF
establishment success. By this performance
index, it can determine interference, packet loss,
wrong parameter setting, instable link failure may
occur in network.
DL Signaling TBF Failure Rate =(C900040149+
C900040150+ C900040151+ C900040152+
C900040153+ C900040154+ C900040155+
C900040156+ C900040157+
C900040158)/(C900040007+ C900040015)*100
DL GPRS Data TBF Failure Rate

DL GPRS Data TBF Failure Rate


This statistic provides TBF proportion
exceptionally released after DL GPRS data TBF
establishment success. By this performance
index, it can determine interference, packet loss,
wrong parameter setting, instable link failure may
occur in network.
DL GPRS Data TBF Failure Rate
=(C900040002+C900040003+C900040004+C90
0040005+C900040006-C900040149C900040150-C900040151-C900040152C900040153)/C900040008*100
UL GPRS Data TBF Failure Rate

UL GPRS Data TBF Failure Rate


This statistic provides TBF proportion
exceptionally released after UL GPRS data TBF
establishment success. By this performance
index, it can determine interference, packet loss,
wrong parameter setting, instable link failure may
occur in network.
UL GPRS Data TBF Failure Rate
=(C900040020+C900040021+C900040022+C90
0040023+C900040024-C900040037C900040038-C900040039-C900040040C900040041)/C900040026*100
UL EDGE Data TBF Failure Rate

UL EDGE Data TBF Failure Rate


This statistic provides TBF proportion
exceptionally released after UL EDGE data TBF
establishment success. By this performance
index, it can determine interference, packet loss,
wrong parameter setting, instable link failure may
occur in network.
UL EDGE Data TBF Failure Rate
=(C900040028+C900040029+C900040030+C90
0040031+C900040032-C900040042C900040043-C900040044-C900040045C900040046)/C900040034*100
DL EDGE Data TBF Failure Rate

DL EDGE Data TBF Failure Rate


This statistic provides TBF proportion
exceptionally released after UL EDGE data TBF
establishment success. By this performance
index, it can determine interference, packet loss,
wrong parameter setting, instable link failure may
occur in network.
DL EDGE Data TBF Failure Rate
=(C900040010+C900040011+C900040012+C90
0040013+C900040014-C900040154C900040155-C900040156-C900040157C900040158)/C900040016*100
UL GPRS Throughput

UL GPRS Throughput


The user UL GPRS data transmitted on air
interface divided by the time taken for data
transmission
UL GPRS Throughput
=C900040058/C900040059*8
DL GPRS Throughput

DL GPRS Throughput


The user DL GPRS data transmitted on air
interface divided by the time taken for data
transmission.
DL GPRS Throughput
=C900040060/C900040061*8
UL EDGE Throughput

UL EDGE Throughput


The user UL EDGE data transmitted on air
interface divided by the time taken for data
transmission.
UL EDGE Throughput
=C900040066/C900040067*8
DL EDGE Throughput

DL EDGE Throughput


The user DL EDGE data transmitted on air
interface divided by the time taken for data
transmission.
DL EDGE Throughput
=C900040068/C900040069*8
DL LLC Signaling Frame Discard Rate

DL LLC Signaling Frame Discard Rate



The statistic provides the percentage of the
discarded downlink LLC signaling frame.
DL LLC signaling frame discard rate equals to the
number of DL signaling LLC frame discard due to
full buffer, exhausted lifecycle, and other
exceptions divided by the number of DL signaling
LLC frame transmitted .
DL LLC Signaling Frame Discard Rate
=(C900040052+C900040053+C900040054)/C90
0040051*100
DL LLC GPRS Data Frame Discard Rate

DL LLC GPRS Data Frame Discard Rate



The statistic provides the percentage of the
discarded DL LLC GPRS data frame.
DL GPRS data frame discard rate equals to the
number of DL GPRS LLC frame discard due to
full buffer, exhausted lifecycle, and other
exceptions divided by the number of DL GPRS
LLC frame transmitted.
DL LLC GPRS Data Frame Discard
Rate=(C900040075+C900040076+C900040077)
/C900040074*100
DL LLC EDGE Data Frame Discard Rate

DL LLC EDGE Data Frame Discard Rate



The statistic provides the percentage of the
discarded DL LLC edge data frame.
DL EDGE data frame discard rate equals to the
number of DL EDGE LLC frame discard due to
full buffer, exhausted lifecycle, and other
exceptions divided by the number of DL EDGE
LLC frame transmitted.
DL LLC EDGE Data Frame Discard Rate
=(C900040048+C900040049+C900040050)/C90
0040047*100
Contents

Overview of traffic statistic
 Traffic statistic KPI
 Locate and analyze network problems
 Traffic statistic analysis instance
Traffic statistic analysis contents
Call drop
TCH congestion
Handover
SDCCH congestion
TCH assignment
SDCCH assignment
General idea
BSC Level
Report
CELL Level
Report
High Call
Drop Rate
Alarm Information
CS Basic Service
Measurement
TRX
Service Measurement
Cell Radio
Measurement
High Congestion
Rate
CS Basic Service
Measurement
Alarm Information
Radio Access
Measurement
Cell Radio
Measurement
High Handover
Failure Rate
Alarm Information
Handover Reason
Measurement
Handover Routine
Measurement
Adjacent Cell Handover
Measurement
CS Basic Service
Measurement
General idea

Combined with:



Driving Test: Analyze coverage、quality、
handover、signaling
CQT: make a great deal of calls in different place
Signaling trace: Collecting signaling through
signaling tools or OMCR signaling trace function
Index Analysis Filter Method
First common, then
Common factors



Hardware
Interference
Coverage
individual factor
Individual factor



Handover
Radio parameters
。。。
Common factors
TCH Call drop
Hardware
Handover
Interference
Congestion
SDCCH Assignment
Coverage
TCH Assignment
Hardware problems
Traffic statistic
basic measurement ：Abnormal
SDCCH and TCH availability, <100%，
Low TCH assignment success rate，
especially >10%
Locate and Solution
CS
BTS
measurement：locate cal drop and
assignment failure on TRX level
Alarm
management：locate hardware

Check transmission error、
repeter self-excitation, TTA noise

Target cell Channel activation
NACK or TIMEOUT；

Call drop because of terrestrial
trunk circuit failure

Calibrate clock

Locate hardware problems
according left traffic statistic,
confirm TRX,CMM,TIC,CDU faults
failure
Dynamic
management：Abnormal TRX
occupation
Check
clock system；
Monitor
transmission system
Interference
Traffic statistic
CS
basic measurement：Analyze
interference band level, change with
time and traffic
Locate and Solution

Frequency check：analyze C/I and
C/A

Frequency scan：Find external
interference

DT：Check interference area and
quality distribution
Adjust BTS’s transmit
power ,antenna downtilt or
frequency etc. to avoid interference;

BTS measurement：locate
interference on TRX level

Handover reason measurement：ratio
of up/down link RQ Handover


Cell radio measurement：Analyze the
distribution of cell level and quality

 Abis

signaling trace：Analyze cells
and TRXs with high interference band
Open FH，DTX，DPC
Fix equipment problems (TRX、
Antenna)
Coverage
Traffic statistic
Locate and solution

CELL performance ：high Up/link
RQ ，bad KPI

Make DT in estimate weak
coverage area


Adjust network parameters based on DT
Power control : Low average
up/down link signal Rx-LEV

Cell radio：Too much low signal
Rx-LEV

Handover reason：too much
rescue handover (Rx-Lev and RxQUAL handover)

Check BTS transmitting power,
antenna downtilt and height,
Rxlev_ACCESS_MIN, the neighbor
cell relationship, RXLEV_MIN of
handover candidate cell.
 Adjust
coverage, avoid overcoverage、weak coverage and lonely
island

Increase BTS sites
Call drop

Type



Radio link time out
Handover failure
LAPD call drop
Call drop analysis
1
Confirm call
drop cell
BSC
level
report
CELL
level
report
2
3
Call drop type
TRX call drop
CELL
level
report
CS
basic
4
BTS
basic
measurement
Cell
Call drop
reason
Common
factor
Particular
radio
Alarm
5
factor
Alarm
analysis
solution
Traffic
statistic
Signaling
analysis
Other
From
whole to
particular
Easy
to locate Locate to TRX
and analysis
method
First common, Execute and
then
solution
particular

Reasons of call drop
Unreasonable HO
parameters
Unbalance up/down
Hardware failure
link
Call drop
Interference
Other parameters
Coverage
Common factor already
discussed
Unreasonable HO parameters
Traffic statistic

Locate and solution
Check if there are unreasonable HO
parameters；

Handover routine measurement:
check outgoing handover failure

Handover reason measurement:
check handover reason and percents
of each kind of handover;

Adjacent cell handover measurement:
Low successful outgoing HO (for
some cells)

CS basic：HO TCH / calling TCH >3
 Make
reasonable neighbor
cells
 Adjust
handover parameters
UL/DL unbalance
Traffic statistic
 CS
basic: UP/DOWN average
Rx_LEV.
 Abis
signaling trace: Analyze
UP/DOWN average Rx_LEV
 Cell
radio measurement: Analyze
UP/DOWN average Rx_LEV
Locate and solution
 Check
TA、CDU、RDU、BTS
boards and RF cable connection
 Check
antenna direction, tiltdown,
feeder and jumper connection,
antenna connector
 Check
VSWR
Other unreasonable parameters
Traffic statistic
 Check
 RLT
Solution
radio parameters：
and Rx-Acc-Min；
 Modify
the unreasonable
parameters
Handover analysis
Low HO success rate
CS Basic
HO measurement
Alarm
Incoming
Incoming/Outgoing
HO routine
HO reason
Outgoing
PBGT
RXLEV
RXQUAL
Adjacent cell
reason
General analysis idea

HO problem cells: all cells or individual cell?
 HO direction: outgoing or incoming HO
failure
 HO target cell: service cell With multi-cell or
With individual cell.
MSC1
BSC3
BSC2
BSC1
1
MSC2
2
3
Checking step of HO





Cells of low HO success rate
Cells of more HO failure numbers
Analyze outgoing/incoming HO failure
number, find out main factors of HO failure
Register out/in handover performance
Observe the feature of HO failure: for all
neighbor cells or single cell, for all conditions
or single reason that lead to HO failure
Probable reasons for HO failure
Common factor already
discussed
Unreasonable
parameters
UP/DOWN
unbalance
Hardware
Coverage
Low HO success
rate
Interference
Unreasonable HO parameter
Traffic Statistic
 Cell
performance：low HO
success rate
 BTS
measurement：find out TRX
with more HO failure
 Handover
reason measurement:
check handover reason and
percents of each kind of handover
 Adjacent
HO measurement: find
out which two cells have HO
failures
Locate and solution
 Check
Pbgt、rescue HO threshold,
HO function switch setting
 Check
TCH assignment due to
HO vs calling 。 If handover/call＞
3，probably Ping-pong HO exist ,
check and adjust handover
parameters setting （Minimum
HO interval、PBGT margin etc）。
Integrated analysis
Traffic statistic

Locate and solution
Cell performance：target cell
congestion

CS basic：low incoming HO success
rate, maybe hardware or interference
problems

Low outgoing HO success rate：
 Target
cell expansion or traffic
balance
 Hardware
maybe target cell congestion or
 Adjust
unreasonable HO parameters
 Adjacent

Adjacent cell： unreasonable neighbor

External cell: frequency, BSIC
troubleshooting
HO parameters
cell optimization
TCH congestion
Capacity or
unbalance traffic
Interference
Antenna system
TCH congestion
Unreasonable
Coverage
parameters
Data configuration
Common factor already
discussed
Shortage of capacity or traffic unbalance
Traffic statistic
Locate and solution
 Cell
 Expansion
 CS
 Adjust
 Cell
 Adjust
performance: Traffic per
channel>0.6
basic: Too much TCH
overflows
performance: Unbalance
traffic
 High
congestion rate
or balance busy and
idle cell TRX configuration
coverage（output power,
antenna direction, tiltdown, height）
cell parameters（CRO，
RX-ACC-MIN, open traffic HO
function）
 Adjust
cell selection priority, cell
HO parameters
Antenna system problems
Traffic statistic
frequency scan: check the
main and diversity antenna
measurement
Solution
 Cell
 Cell
radio measurement: signal
level, quality , interference
band
 Signaling
tracing:
measurement report analysis.
 Check
antenna azimuth,
downtilt, connection of antenna
and feeder system.
Unreasonable cell parameters
Traffic statistic
 Performance
Solution
report: check TCH
congestion
 Alarm
statistic: BTS or TRX
hardware failure
 BTS
measurement: check if TRX
problem?
 Check
cell parameters: Rx-AccMin, cell resection parameters
 Adjust
unreasonable
parameter
 Hardware
troubleshooting
SDCCH congestion
引起SDCCH
Unreasonable
拥塞率高的几
Para.
个主要因素：
Interference
SDCCH congestion
Capacity limit
Unreasonable LAC
Common factor already
discussed
Unreasonable parameters
Traffic statistic
Solution
 CS
basic: Check reason of
SDCCH congestion
 Radio
access: Immediate
assignment success / Immediate
assignment > 85%
 Check
para: All parameters with
relation to radio access
 SDCCH
available rate
 Adjust
parameter: Random access
threshold, RACH access threshold，
MaxRetrans，Tx-Integer
 T3212；
 Dual
band parameter adjustment
System capacity limit
Traffic statistic
 Cell
Solution
performance：Both TCH and
SDCCH congestion
 Cell
performance：TCH no
congestion but SDCCH
congestion
 Cell
location：Traffic hub such as
airport, railway station
 SMS
increase greatly
 Expansion
 Increase
 Adjust
SDCCH
T3122、T3212、
RACH……
Unreasonable LAC planning
Traffic statistic
 Cell
performance：SDCCH
congestion
 CS
Basic：too much location
update
 LAC
planning：LAC border cross
heavy traffic area
Solution
 Modify
CRH；
 Adjust
cell reselection para.
 Modify
T3212；
 Adjust
other para.
Interference
Traffic statistic
 Low
RACH threshold, at the same
time, there is interference
 Cell
performance：SDCCH
congestion
 CS
basic：SDCCH invalid access
Solution
 Check
and adjust frequency
planning
 Check
and remove interference
 Adjust
access para.
SDCCH assignment failure
CCCH congestion
Interference
Transmission
Reason
Bad coverage
Hardware
Software version
Common factor already
discussed
SDCCH assignment failure
Traffic statistic
 CCCH
Solution
congestion：not enough
AGCH
 CS
basic：Uplink interference
band, abnormal UP/DOWN RQ
 Alarm：equipment
hardware
failure
system monitor：
locate transmission problem
version
PCH and AGCH block
numbers
 Frequency
 Work
 Transmission
 Software
 Adjust
check
out transmission problems
 Upgrade
software version
TCH assignment failure
Success assignment
Assignment failure
TCH assignment analysis
3
2
It is carried out
between BSC
 BSC sends
and MS. When
Channel Activation BSC receives
to BTS， receives Establish
BTS’s feedback
Indication, TCH
message Channel
assignment is
Activation ACK,
successful.
then allocation has
Allocation
1
Occupation
After
receives
CHANNEL
REQUIRE
command,
BSC will
inquire channel
resources in
MP database.

Assignment
been done.

Reason of TCH assignment failure






Hardware: TRX、CDU、RF cable connection
Interference: C/I,C/A or external interference
Antenna feeder: Antenna and feeder damage,
linear antenna direction, downtilt not same, VSWR,
feeder cable cross connection
Unreasonable para: HSN/MAIO, T3107 small,
configuration para is different from planning
Coverage: weak coverage or UP/DOWN unbalance
Repeater: Induce UP/DOWN interference and
unbalance
TCH assignment failure
Traffic statistic
Solution
 Cell
performance：cells of TCH
assignment failure
 Check
Basic：interference band、
call drop、handover、UP/DOWN
 Check
RQ level
 Check
 CS
BER、interference band,
decrease interference
 Alarm：Hardware
 Driving
 BTS
 Check
measurement：locate TRX
with TCH assignment failure
 NMS
TRX：The time and number
of TCH and SDCCH assignment
cell radio para
hardware problem
test analysis
if BSC and BTS software
version match
Contents

Overview of traffic statistic
 Traffic statistic KPI
 Locate and analyze network problems
 Traffic statistic analysis instance
Call drop instance

Description


From 16 March, Cell I102 of BSC80 call drop number increase
greatly，Call drop rate（include handover）>7%
Analysis






Cell performance: call drop type: radio link failure
Interference band: a lot of strip 3
Check frequency planning: no problem
BTS measurement: TRX2 and TRX3 high assignment failure rate
Alarm: no
Handover parameters: TRX2 and TRX3 have same MAIO
Call drop instance

Solution

Region
Change MAIO of TRX3 to 10
Cell
Name
BSC ID
CELL ID
TCH in call drop
rate(%)
Remark
8.17
7.74
before
7.53
7.97
NORTH
I102
80
50022
1.03
0.94
after
0.85
0.76
Handover instance 1

Description


Analysis



Cell performance: Site A cell 1 handover success rate
low
Unreasonable parameter: No
From OMCR dynamic management: one TRX can not
be occupied, probably hardware problem
Solution

Change TRX, everything OK
Handover instance

Result
HO
success
HO
success
rate(%)
Site name
(LAC-CI)
HO
request
D1A
LAC8415-CI25023
345
52
15.1
D1A
LAC8415-CI25023
221
64
29
D1A
LAC8415-CI25023
266
28
10.5
D1A
LAC8415-CI25023
160
152
95
D1A
LAC8415-CI25023
160
154
96.3
TCH congestion instance 1

Description


Analysis



From 21 Dec. according to cell performance report，site 106
sector 3 of BSC8 in Libyan network, there is great TCH congestion,
TCH congestion rate (exclude handover)>30%
There is no congestion for this sector before, TCH congestion rate
increase suddenly
Check cell performance and alarm of its neighboring cells，we
found one neighboring site 127 which locate oppositely suffered
power break, a lot of traffic was absorbed by site 106
Solution

After the power come back ,site 127 work properly, and site 106
TCH congestion disappeared
TCH congestion instance 1
BSC-SITE ID-BTS
(LAC-CI)
SDCCH
congestion
rate(%)
TCH congestion
rate (exclude
handover)(%)
TCH overflow
(exclude handover)
Bsc8-Site106-Bts1
LAC8198-CI11061
0
0
0
Bsc8-Site106-Bts2
LAC8198-CI11062
0
0
0
Bsc8-Site106-Bts3
LAC8198-CI11063
0.04
30.24
936
After adjustment
Bsc8-Site106-Bts1
LAC8198-CI11061
0
0
0
Bsc8-Site106-Bts2
LAC8198-CI11062
0
0
0
Bsc8-Site106-Bts3
LAC8198-CI11063
0.04
0
0
TCH congestion instance 2



Description

In the evening of 2, April, we configured dynamic GPRS channel
to BSC1. and observed at daytime on 3, April, we found TCH
congestion rate went up remarkably.
Analysis
 Decrease dynamic GPRS to one channel per cell before busy hour
on 3, April

We observed next day and found that, 11654(TCH assignment
failure number) of many cells under BSC1 is still very high
 Signaling trace: Channel Activation failed for all the TCH come
from GPRS dynamic channel
Solution
 Change dynamic GPRS channel to static channel, then to TCH
channel, network restored to normal.
SDCCH congestion instance

Description


Analysis




Site 61, Cell 3 , SDCCH congestion rate increase
suddenly after put into service>35%
CS basic: there are many location update.
LAC planning is OK
Probably data configuration problem
Solution


We found LAC of Cell 3 is 8198，but the LAC of the
other two cells is 8199
Change back LAC to 8199
SDCCH assignment instance

Description


Analysis



One BTS connect BSC by satellite , some type of
handset can not call properly
Signaling trace: there is no EST IND after BSC send
IMMDIEATE ASSIGNMENT COM，and BSC release
the channel
For satellite transmission, the transmission delay
between MS and BTS is about 150ms , this led some
type of handset can not receive Immediate assignment
command within required period.
Solution

BSC adopted optimized Immediate assignment process
TCH assignment instance

Description


Analysis




Cell 3 of site 1, TCH assignment failure rate:12.28, Call
drop rate:6.9%, Handover in success rate:68.38%,
Handover out success rate:91.31%
TCH assignment failure rate>10%, from which we can
exclude interference, maybe there is hardware problem.
BTS measurement: We found the second TRX has high
TCH assignment failure>30%，
CQT: we found when the second TRX was occupied,
the Rx-Lev is 20dB less than that of BCCH.
Solution

Change TRX
TCH assignment instance
BSC -SITE
ID-BTS
(LAC-CI)
Bsc80Site1-Bts3
LAC1003CI50003
TCH call drop
rate (include
handover)(%)
TCH call drop
number
TCH assign
failure
rate(%)
Handover in
success
rate(%)
Handover
out success
rate(%)
6.9
98
12.28
68.38
91.31
2.28
92.38
92.89
After adjustment
Bsc80Site1-Bts3
LAC1003CI50003
0.9
5