LTE Basic Optimisation
1
© Nokia Siemens Networks 2013
Summary of LTE Optimization Team Tasks
I. LTE Site Information
II. LTE Site Health & Stability Check After Integration
III. LTE Neighbour Definition & Creation
IV. LTE Parameter Consistency Check
IV. LTE Drive Test & Analysis
IV. LTE KPI & Performance Analysis
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LTE Site Information
- Physical Layer Cell ID (PCI)
- RACH Root Sequence Index
- Tracking Area Code (TAC)
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© Nokia Siemens Networks 2013
Physical Layer Cell ID (PCI)
What is the PCI ?
 Physical Layer Cell Identity (PCI) identifies a cell within a network.
 There are 504 Physical Layer Cell Identities. So, PCI is not unique!
 PCI is defined by the parameter phyCellID :
4
Parameter
Object
Range
Default
phyCellID
LNCEL
0 to 503
-
© Nokia Siemens Networks 2013
PCI Planning
Id = 0
Principle
Id = 2
 UE should never receive simultaneously the same PCI from more
than one cell.
 Neighbour cells should not have the same PCI (collision free).
 Neighbour of neighbour cells should not have the same PCI
(confusion free).
In priority order, below are the recommendations when planning the PCI.
No.1 is the most important. All four should be fulfilled, ideally.
Id = 6
Id = 8
Id = 1
Id = 3
Id = 5
Id = 7
Id = 9
Id =
11
Id = 4
Id =
10
Example 1 PCI Identity Plan
1. Avoid assigning the same PCI to neighbour cells.
2. Avoid assigning the same mod3(PCI) to neighbour cells.
3. Avoid assigning the same mod6(PCI) to neighbour cells.
4. Avoid assigning the same mod30(PCI) to neighbour cells.
Example 2 PCI Identity Plan
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PRACH Planning
Principle
 PRACH configuration of two cells must be different within the PRACH re-use distance to increase the
RACH decoding success rate.
PRACH transmission can be separated by:
• Time (prachConfIndex)
• Frequency (prachFreqOff)
• Sequence (prachCS and RootSeqIndex)
6
Parameter
Object
Range
Default
prachConfIndex
LNCEL
3...24, step 1
3
prachFreqOff
LNCEL
0…94, step 1
-
prachCS
LNCEL
0…15, step 1
12
RootSeqIndex
LNCEL
0…837, step 1
-
© Nokia Siemens Networks 2013
PRACH Planning
Planning Steps
1. Define the PRACH Configuration Index (prachConfIndex)
• Depends on preamble format which depends on the cell range.
• PrachConfIdenx should be the same for each cell of a site.
2. Define the PRACH Frequencey Offset (prachFreqOff)
• Depends on the PUCCH region.
• For simplicity, prachFreqOff can be assumed to be the same for all cells of a network.
3. Define the PRACH Cyclic Shift (prachCS)
• Depends on the cell range.
• If, for simplicity, same cell range is assumed for all network, then prachCS is the same for all cells.
4. Define the RACH Root Sequence (rootSeqIndex)
• It points to the first root sequence.
• It needs to be different for neighbour cells.
• RootSeqIndex separation between cells depends on how many are necessary per cell (i.e.
depends on PrachCS)
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© Nokia Siemens Networks 2013
PRACH Planning
PRACH Configuration Index, PRACH Frequency Offset, PRACH Cyclic Shift
Cell Range
PUCCH
Region
If PRACH area is placed at the lower
border of UL frequency band, then :
prachFreqOff = roundup [PUCCH
resources/2]
RACH Density = 1
If PRACH area is placed at the upper
border of UL frequency band, then :
prachFreqOff = NRB – 6 –
roundup [PUCCH resources/2]
prachConfIndex = 3
prachFreqOff = 4
prachCS = 12
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© Nokia Siemens Networks 2013
PRACH Planning
RACH Root Sequence
PRACH Cyclic Shift defines the number of cyclic shift (in terms of number
of samples) used to generate multiple preamble sequences from a single
root sequence.
prachCS = 12  number of cyclic = 119
Root sequence length is 839. So a cyclic shift of 119 means :
roundown [839/119] = 7 signatures per root sequence
64 preambles are transmitted in the PRACH frame.
If one root sequence is not enough to generate 64 preambles,
then more root sequences are required. So :
Roundup [64 preambles / 7] = 10 root sequences per cell
Root Sequence Index points to the first root sequence to be
used when generating the set of 64 preamble sequences.
rootseqIndex = 0, 10, 20,
30, …,820, 830
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© Nokia Siemens Networks 2013
Recommendation :
Use different Root Sequence Index across neighbouring
cells to ensure neighbour cells will use different
preamble sequences
Tracking Area Code (TAC)
 Tracking Area Code (TAC) for LTE sites has been planned and allocated by Access Network Design
Team as below.
Region
Auckland CBD
41216
Auckland South and Airport
41760
Auckland South West
41840
Auckland North
41264
Auckland West
41248
Auckland South
41776
Greater Auckland
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© Nokia Siemens Networks 2013
TAC
41744, 41280
LTE Site Health & Stability Check
After Integration
- BTS Status Check
- Alarms Check
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BTS Status & Alarms Check
Using Top Level User Interface
 After the site is
integrated, BTS Status
and Alarms can be
checked from NetAct
using “Top Level User
Interface”.
Opening a View
& Search/Select
ALARM
MONITOR
STATUS
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BTS Status & Alarms Check
Using BTS Site Browser
STATUS
ALARM
MONITOR
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 BTS
Status
and
Alarms can also be
checked from NetAct
using
“BTS
Site
Browser”.
BTS Status & Alarms Check
Using BTS Site Manager
 BTS
Status
and
Alarms can also be
checked by logging into
the site using “BTS Site
Manager”.
STATUS
ACTIVE
ALARMS
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Common Alarms (1)
7651 BASE STATION OPERATION DEGRADED
 S1 SCTP Path Failure
 Check the connection to MME using IP connectivity test from BTS Site Manager.
 GTPU Path Failure
 Check the connection to S-GW using IP connecitivity test from BTS Site Manager.
Failure in Optical RP3 Interface
 Check the optical cables connection between System Module and RF Module.
7654 CELL OPERATION DEGRADED
 RF Module Failure
 Check/ replace the RF Module.
7655 CELL NOTIFICATION
 TX Failure in MIMO
 Faulty Tx in RF module. Check/replace the RF Module or change dlMimoMode to “Single Tx” to clear the alarm.
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Common Alarms (2)
7657 BASE STATION CONNECTIVITY DEGRADED
Transport Layer Connection Failure in X2 Interface
 Check the connection to adjacent BTS using IP connectivity test from BTS Site Manager .
Transport Layer Connection Failure in S1 Interface
 Check the connection to MME using IP connectivity test from BTS Site Manager.
 LOS/LOF on unit $U, Interface $IF
 Check the Transmission Module or the connection to the far end node.
Synchronisation Lost
 Check the connection to the synchronization source.
7652 BASE STATION NOTIFICATION
 BTS Reference Clock Missing
 Check the connection to the synchonization source.
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LTE Neighbour Definition & Creation
- Intra-LTE Mobility
- Inter-RAT Mobility
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LTE Mobility and Related Features in RL30
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LTE-WCDMA Interworking
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© Nokia Siemens Networks 2013
LTE-GSM Interworking
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© Nokia Siemens Networks 2013
RL40 Parameter Object Structure
(Example objects)
LNMME
0..255
1..16
LNADJ
LNADJG
LNADJW
0..63
0..255
neighbor eNB
0..11
LNBTS
LNADJL
serving eNB
LNRELG
LNRELW
LNREL
0..5
max 32 per freq for CIO
Total 389
0.. 255
0..255
LNHOG
LNCEL
0..6
serving eNB cell
LNHOW
0..15
LNHOIF
1..16
21
REDRT
1..6
© Nokia Siemens Networks 2013
IAFIM
1..1
IRFIM
1..6
UFFIM
1..1
GFIM
1..1
CDFIM
1..1
Idle Mode Mobility Parameter in eNB Database
LNBTS
[LTE Basestation RNW parameters]
6
LNCEL
LNCEL
[LTE BTS CELL RNW parameters]
LNCEL
[LTE BTS
CELL RNW parameters]
LNCEL
[LTE BTS CELL RNW parameters]
LNCEL
[LTE BTS
CELL RNW parameters]
LNCEL
[LTE BTS
CELL RNW parameters]
[LTE BTS CELL RNW parameters]
1
8
1
IAFIM
IRFIM
IRFIM
IRFIM
IntrA
Frequency
Idle Mode
parameters
InteR
InteR
Frequency
InteR
Frequency
Idle Mode
Frequency
Idle
Mode
parameters
Idle
Mode
parameters
parameters
UFFIM
UTRAN FDD
Frequency
Idle Mode
parameters
CDFIM
CDMA200
Frequency
Idle Mode
parameters
GFIM
GERAN
Frequency
Idle Mode
parameters
GNFL
GERAN
Neighbor
GNFL
Frequency
List
GERAN
GNFLNeighbor
parameters
Frequency
List
GERAN Neighbor
parameters
Frequency
List
parameters
1
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© Nokia Siemens Networks 2013
16
Idle mode mobility
L1800 FDD
•Abs Priority 6
Reselect L1800 if
L1800 RSRP > -120
Always meas
LTE (SIB19)
UMTS
Start Measure Inter
Freq / RAT if
L1800 RSRP < -120
Reselect UMTS if
L1800 RSRP < -124
and
UMTS RSCP > -105
and
UMTS ECNO > -16dB
•Abs Priority 3
Reselect UMTS if
UMTS ECNO > -12dB
GSM
Always meas UMTS
(QSearchI)
•Abs Priority 0
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© Nokia Siemens Networks 2013
Reselect GSM if
L1800 RSRP < -124
and
RxLev > -102
Idle mode mobility
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
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Operation
Function
S-Criteria
IDLE MODE
R-Criteria
3G--> LTE
© Nokia Siemens Networks 2013
Managed Object
Parameter Name
LTE_LNCEL_SIB
LTE_LNCEL
LTE_LNCEL_SIB
LTE_LNCEL_SIB
LTE_IRFIM
LTE_UFFIM_UTRFDDCARFRQL
LTE_GNFL
LTE_CDFIM_HRPDBDCLLIST
LTE_CDFIM_RTTBDCLLIST
LTE_LNCEL_SIB
LTE_LNCEL_SIB
UE class specific max
LTE_LNCEL
LTE_IAFIM_INTRFRNCLIST
LTE_LNCEL
LTE_IRFIM_INTFRNCLIST
LTE_IRFIM
LTE_IRFIM
LTE_IRFIM
LTE_IRFIM
LTE_IRFIM
LTE_UFFIM_UTRFDDCARFRQL
LTE_UFFIM_UTRFDDCARFRQL
LTE_UFFIM_UTRFDDCARFRQL
LTE_UFFIM_UTRFDDCARFRQL
LTE_UFFIM_UTRFDDCARFRQL
LTE_UFFIM_UTRFDDCARFRQL
LTE_UFFIM_UTRFDDCARFRQL
LTE_LNCEL_SIB
LTE_LNCEL_SIB
HOPL
HOPL
HOPL
HOPL
qrxlevmin
qRxLevMinOffset
pMaxOwnCell
cellReSelPrio
eutCelResPrio
uCelResPrio
gCelResPrio
hrpdCResPrio
rttCResPrio
Sintrasearch
sNonIntrsearch
UL Tx power
qHyst
qOffsetCell
tReselEutr
qOffCell
qOffFrq
interFrqThrH
qRxLevMinInterF
interTResEut
interFrqThrL
qRxLevMinUtra
qQualMinUtra
pMaxUtra
uCelResPrio
utraFrqThrH
utraFrqThrL
dlCarFrqUtra
threshSrvLow
intrFrqCelRes
AdjLQrxlevminEUTRA
AdjLAbsPrioCellReselec
AdjLThreshigh
AdjLThreslow
WCEL_SIB
WCEL_SIB
WCEL_SIB
WCEL_SIB
WCEL_SIB
RNFC
RNC
AbsPrioCellReselec
LTECellReselection
Sprioritysearch1
Sprioritysearch2
Threshservlow
EUTRAdetection
SIB19Priority
Planned
-130
0
33
6
Not Used
3
0
Not Used
Not Used
62
8
Cat 3
1
Not Used
1
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
-105
-16
33
3
4
0
10663
6
Not Used
-65
7
5
0
3
1
0
0
0
1
3
Internal
GUI Value
Value
Unit in
GUI
-130
0
33
6
3
62
8
23
1
1
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
-105
-16
33
3
4
0
10663
6
0
-65
7
5
0
3
1
0
0
0
1
3
dBm
dB
dBm
dB
dB
dBm
dB
dB
second
dB
dB
dB
dBm
second
dB
dBm
dB
dBm
dB
dB
dB
dBm
dB
dB
dB
dB
dB
-
-130
0
33
6
3
62
8
23
1
1
-105
-16
33
3
4
0
F1
6
allowed
-130
7
10
0
3
TRUE
0
0
0
TRUE
3
Connected Mode Mobility Parameter in eNB Database
LNBTS
[LTE Basestation RNW parameters]
6
1
LNCEL
LNCEL
LTE
BTS CELL
LNCEL
LTE BTS CELL
RNW parameters
LTERNW
BTS CELL
parameters
RNW parameters
LNADJW
LNADJW
Neighboring
LNADJW
Neighboring
LNADJG
LNADJG
Neighboring
LNADJG
Neighboring
WCDMA Cell
Neighboring
WCDMA Cell
WCDMA Cell
32
LNADJ
GERAN BTS Cell
Neighboring
GERAN BTS Cell
GERAN BTS Cell
32
1
LNADJ
Neighboring
LTE
LNADJ
Neighboring
LTE
BTS
Neighboring
LTE
BTS
BTS
1
1
LNHOIF
LNHOIF
LNHOIF
Handover
Handover
parameters
Handover
parameters
to
parameters
to
neighboring
to
neighboring
Interneighboring
Interfrequency
Interfrequency
LTE Cell
frequency
LTE Cell
LTE Cell
1
16
LNHOG
LNHOG
LNHOG
LNHOW
LNHOW
LNHOW
Handover
Handover
parameters
Handover
parameters
to
parameters
to
neighboring
to
neighboring
GERAN BTS
neighboring
GERANCell
BTS
GERANCell
BTS
Cell
Handover
Handover
Handover
parameters
parameters
parameters
to
to
to
neighboring
neighboring
neighboring
WCDMA BTS
WCDMA
BTS
WCDMA
BTS
Cell
CellCell
1
25
© Nokia Siemens Networks 2013
6
1
LNREL
LNREL
LNREL
REDRT
LNADJL
LNADJL
LNADJL
LTE
LTE
neighbor
LTE
neighbor
relation
neighbor
relation
relation
Redirection
target
parameters
Neighboring
Neighboring
LTE BTS Cell
Neighboring
LTE BTS Cell
LTE BTS Cell
6
389
16
1
64
1
Dedicated mode mobility
L1800 FDD
•Abs Priority 6
Reselect L1800 if
L1800 RSRP > -120
Only when UMTS in
URA/CELL – PCH /
Idle Mode
Always meas
LTE (SIB19)
UMTS
•Abs Priority 3
HO to UMTS when
Ec/No > -10 and
RSCP > -95
Note : for some 2G Cells
GSM
Always meas UMTS
(QSearchC)
•Abs Priority 0
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© Nokia Siemens Networks 2013
Start Measure UMTS
if L1800 RSRP < 100
HO to UMTS via PS
Handover (using
RSCP)
L1800 RSRP < -110
and
UMTS RSCP > -96 and
Start Compressed Mode
(RT) if UMTS
RSCP < -105
or Ec/No < -14
(NRT/HSDPA)
RSCP < -110
or Ec/No < -16
HO to UMTS via
Redirection (using RSCP)
L1800 RSRP < -120
HO to GSM
GSM RxLev > -102
Dedicated mode mobility
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
27
Operation
Function
ACTIVATE
MEASUREMENT
DE-ACTIVATE
MEASUREMENT
BETTER CELL-HO
Connected
Mode
COVERAGE HO
S1-HO
INTER FREQ HO
© Nokia Siemens Networks 2013
Managed Object
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNBTS
LTE_LNBTS
LTE_LNBTS
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
LTE_LNHOIF
Parameter Name
Planned
threshold1
threshold2InterFreq
threshold2Wcdma
threshold2GERAN
hysThreshold2InterFreq
hysThreshold2Wcdma
hysThreshold2GERAN
a2TimeToTriggerActInterFreqMeas
a2TimeToTriggerActWCDMAMeas
a2TimeToTriggerActGERANMeas
threshold2a
hysThreshold2a
a1TimeToTriggerDeactInterMeas
enableBetterCellHo
a3Offset
a3TimeToTrigger
a3ReportInterval
enableCovHo
threshold3
threshold3a
a5TimeToTrigger
a5ReportInterval
hysThreshold3
actLTES1Ho
prioTopoHO
actIfHo
eutraCarrierInfo
hysA3OffsetRsrpInterFreq
hysA3OffsetRsrqInterFreq
measQuantInterFreq
a3TimeToTriggerRsrpInterFreq
a3TimeToTriggerRsrqInterFreq
a3OffsetRsrpInterFreq
a3OffsetRsrqInterFreq
a3ReportIntervalRsrpInterFreq
a3ReportIntervalRsrqInterFreq
measQuantInterFreq
hysThreshold3InterFreq
threshold3aInterFreq
threshold3InterFreq
a5TimeToTriggerInterFreq
a5ReportIntervalInterFreq
90
Not Used
40
Not Used
Not Used
0
0
9
8
8
80
0
480
TRUE
3
320
240
TRUE
30
32
320
240
0
TRUE
0
0
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Not Used
Internal
Unit in
GUI Value
Value
GUI
90
-50
dBm
98
Not Used
dB
40
-100
dBm
0
-140
dBm
0
0
dB
0
0
dB
0
0
dB
9
480
ms
8
320
ms
8
320
ms
80
-60
dBm
0
0
dB
9
480
ms
1
TRUE
6
3
dB
8
320
ms
1
240
ms
1
TRUE
30
-110
dBm
32
-108
dBm
8
320
ms
1
240
ms
0
0
dB
1
TRUE
0
all equal
0
disabled
dB
dB
ms
ms
dB
dB
ms
ms
dB
dBm
dBm
ms
ms
Dedicated mode mobility
No
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
28
Operation
Function
LTE Mobility Offsets
ReDirection
Connected Mode
LTE to UMTS (PS HO)
© Nokia Siemens Networks 2013
Managed Object
LTE_LNCEL_HC
LTE_LNREL
LTE_LNCEL_HC
LTE_LNHOIF
LTE_LNBTS
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_MODRED
LTE_MODRED
LTE_LNBTS
LTE_LNCEL_HC
LTE_LNCEL_HC
LTE_LNHOW
LTE_LNHOW
LTE_LNHOW
LTE_LNHOW
LTE_LNHOW
LTE_LNHOW
LTE_LNHOW
LTE_LNHOW
LTE_LNHOW
LTE_LNHOW
LTE_LNHOW
Parameter Name
cellIndOffServ
cellIndOffNeigh
offsetFreqIntra
offsetFreqInter
actRedirect
threshold4
a2TimeToTriggerRedirect
hysThreshold4
redirRat
redirFreqUtra
actHOtoWcdma
measQuantityUtra
measQuantityCSFBUtra
b1TimeToTriggerCSFBUtraMeas
b1ThresholdCSFBUtraEcn0
b1ThresholdCSFBUtraRscp
hysB1ThresholdCSFBUtra
b2TimeToTriggerUtraMeas
hysB2ThresholdUtra
b2Threshold1Utra
b2Threshold2UtraRscp
b2Threshold2UtraEcn0
reportIntervalUtra
utraCarrierFreq
Planned
Internal
Value
GUI Value
Unit in
GUI
default
default
default
Not Used
Enabled
20
160
0
2
10663
1
0
0
7
4
10
4
9
0
30
19
28
1
10638
15
15
15
1
20
7
0
2
10663
1
0
0
7
4
10
4
9
0
30
19
28
1
10638
0
0
0
Enabled
-120
160
0
utraFDD
F1
TRUE
cpichRSCP
cpichRSCP
256
-22
-105
2
512
0
-110
-96
-10
240
F2
dB
dB
dB
dB
dBm
ms
dB
ms
dB
dBm
dB
ms
dB
dBm
dBm
dB
ms
-
Intra-LTE Connected Mode Mobility via X2 (1)
1. Create LNADJ
 LNADJ can be created via BTS Site Manager :
Required information
from neighbour cell :
• c-plane IP address
• eNB ID
or via plan using CM Editor.
29
© Nokia Siemens Networks 2013
Intra-LTE Connected Mode Mobility via X2 (2)
2. LNADJL and LNREL creation
 If X2 link is available, LNADJL will be created automatically by system during initial X2 setup procedure.
LNREL will also be created automatically by system.
30
© Nokia Siemens Networks 2013
Intra-LTE Connected Mode Mobility via S1 (1)
1. Activate Intra-LTE S1 Based Handover
2. Create LNADJ
 The same as LNADJ creation for X2-based Handover, but ‘C-Plane IP address control’ must be set to “enbControlled”.
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© Nokia Siemens Networks 2013
Intra-LTE Connected Mode Mobility via S1 (2)
3. Create LNADJL & Primary PLMN ID of Neighbour eNB
4. LNREL creation
 LNREL will be created automatically by system.
32
© Nokia Siemens Networks 2013
Idle Mode Mobility from LTE to WCDMA
1. Activate SIB6
 SIB6 contains information about UTRA frequencies and UTRA neighbouring cells relevant for cell-reselection.
The parameters are grouped in UFFIM object.
2. Create UFFIM
 UFFIM = UTRAN FDD Frequency Idle Mode Parameters.
 Up to 16 WCDMA FDD Frequency Groups can be broadcasted.
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© Nokia Siemens Networks 2013
Idle Mode Mobility from LTE to GSM
1. Activate SIB7
 SIB7 contains information about GERAN frequencies relevant for cell-reselection.
The parameters are grouped in GFFIM and GNFL object.
2. Create GFIM & GNL
 GFIM = GERAN Frequency Idle Mode Parameters. GNFL = GERAN Neighbour Frequency List Parameters.
 Up to 16 GERAN Frequency Layers can be broadcasted.
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RRC Connection Release with Redirect & CSFB via Redirect
1. Activate RRC Connection Release with Redirect Feature
2. Activate CSFB to UTRAN/GSM via Redirect Feature
3. Create REDRT
 Depending on target RAT for redirection, target RAT parameters must be set in REDRT.
 Up to 6 REDRT can be defined.
Target : 3G
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Target : 2G
PS Handover to WCDMA (1)
1. Activate PS Handover to WCDMA
2. Create LNADJW
 Up to 32 LNADJW can be defined.
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PS Handover to WCDMA (2)
3. Create LNHOW
 LNHOW contains information about WCDMA thresholds and timers for predefined set of ARFCNs.
 Up to 16 LNHOW profile can be defined.
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LTE Parameter Consistency Check
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Parameter Dump
Object Classes
Network Element
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Parameter Consistency Check
Parameter Template
Actual Parameter
(e.g. Golden Parameter,
NPT, etc.)
(from Dump)
LNBTS
• Features activation
E.g. :
- actRedirect
- actCSFBRedir
- actLTES1Ho
- actHOtoWcdma
LNCEL
• Admission Control
E.g. : - maxNumActUE
- maxNumRrc
• Handover Control
E.g. : - threshold/offset/
timer for handover
• Random Access
E.g. : - prachCS
- prachConfIndex
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REDRT
• Packet Scheduler
E.g. : - dlamcEnable
- dl64QamEnable
- dlMimoMode
- maxNumUeDl
- maxNrSymPdcch
• Power Control
E.g. : - ulpcEnable
UFFIM
• Redirection to 3G/2G
• Idle Mode Mobility to 3G
E.g. : - redirRat
- redirFreqUtra
- csFallBPrio
- redirectPrio
E.g. : - dlCarFrqUtra
- qQualMinUtra
- qRxLevMinUtra
- uCelResPrio
LTE Drive Test & Analysis
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Drive Test Output
The following problems can be detected from drive test.
 Overshooting.
 Pilot Pollution.
 Missing Neighbour.
 Un-optimized Parameters.
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Pilot Pollution
What is Pilot Pollution ?
 Less than 3 - 5 dB different RSRP among PCIs are considered as potential interfering PCIs.
How to detect ?
 Based on drive test log.
 Check serving PCI versus Top 4 PCIs.
 Less than 3 - 5 dB different RSRP among PCIs are considered as potential interfering PCIs.
 Count PCIs less than 5 dB RSRP different.
 Count 3 ~ 4 PCIs should be considered for antenna optimization.
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Pilot Pollution
DL Radio Quality
 Possible problems :
• Reduction of SINR
• Increase of DL interference from other cells
• Frequent handover
Lower SINR area is matched
together with multiple PCIs area
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Pilot Pollution
UL Radio Quality
 In area with low RSRP, UL Power Headroom is limited.
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Pilot Pollution
Counted PCIs
Pollution
 There are 4 ~ 6 PCIs with less than 3 dB different of RSRP.
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RSRP
Pilot Pollution
After Antenna Downtilting
Before
 After antenna downtilting, SINR is improving.
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After
Pilot Pollution
After Antenna Downtilting
Before
After
 The number of Handover attempts has been reduced which is indicating more clear dominant areas after antenna
downtilting.
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Pilot Pollution
After Antenna Tilting
Before
After
Before
After
 SINR improvement is around 2 dB.
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Pilot Pollution
After Antenna Tilting
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Missing Neighbour
How to detect ?
 Perform drive test (PING test should be enough).
 Consider measurement reports without Handover command as missing neighbours.
 Monitor Handover performance from drive test and KPIs.
 Monitor other KPIs (such as CSSR, Drop Rate, Early Handover, Late Handover, etc.).
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Missing Neighbour
Measurement Reports without Handover Command
Serving
PCI
Missing
Neighbour PCI
501
449
A lot of Measurement
Reports but no
Handover Command
UE is reporting to the
serving cell (PCI 501) a
neighbour cell (PCI 449)
with stronger signal.
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Source
eNB ID
Target
eNB ID
Target eNB
c-plane ip
address
501
449
10.48.7.182
Create LNADJ
LTE KPI & Performance Analysis
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KPI Formula
KPI Name
KPI ID
Formula
Cell Availability
LTE_5750a 100*sum(SAMPLES_CELL_AVAIL)/sum(DENOM_CELL_AVAIL)
RRC Setup Success Ratio
100*sum([SIGN_CONN_ESTAB_COMP]) / sum([SIGN_CONN_ESTAB_ATT_MO_S]+
[SIGN_CONN_ESTAB_ATT_MT]+ [SIGN_CONN_ESTAB_ATT_MO_D]+
LTE_5218c
[SIGN_CONN_ESTAB_ATT_OTHERS] +
[SIGN_CONN_ESTAB_ATT_EMG])
E-RAB Setup Success Ratio
LTE_5017a 100*(EPS_BEARER_SETUP_COMPLETIONS) / (EPS_BEARER_SETUP_ATTEMPTS)
E-RAB Drop Ratio
100*sum(ENB_EPS_BEARER_REL_REQ_RNL + ENB_EPS_BEARER_REL_REQ_TNL +
ENB_EPS_BEARER_REL_REQ_OTH) / sum(EPC_EPS_BEARER_REL_REQ_NORM +
EPC_EPS_BEARER_REL_REQ_DETACH + EPC_EPS_BEARER_REL_REQ_RNL +
LTE_5025b
EPC_EPS_BEARER_REL_REQ_OTH + ENB_EPSBEAR_REL_REQ_RNL_REDIR +
ENB_EPS_BEARER_REL_REQ_NORM + ENB_EPS_BEARER_REL_REQ_RNL +
ENB_EPS_BEARER_REL_REQ_TNL + ENB_EPS_BEARER_REL_REQ_OTH)
Intra eNB HO Success Ratio,
LTE_5043a 100*(SUCC_INTRA_ENB_HO) / (INTRA_ENB_HO_PREP)
Total
Inter eNB HO Success Ratio,
LTE_5058b 100*(SUCC_INTER_ENB_HO) / (INTER_ENB_HO_PREP)
Total
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Reports & KPI
Cell Availability
RSLTE000
System Program
(Cell Level)
RSLTE004
Network Access – Service
Access and RRC
RSLTE037
Service Retainability
RSLTE005
HO Analysis
RRC Setup
Success Rate
E-RAB Setup
Success Rate
E-RAB DropRate
Intra-eNB HO
Success Rate
RSLTE031
Neighbour HO Analysis
RSLTE024
RSSI for PUSCH
Inter-eNB HO
Success Rate
PCI Confusion
RSLTE025
SINR for PUSCH
RSLTE019
Power
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Uplink Interference
Radio Quality
OSS Statistics
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PCI Planning Review  Mod3 Violation
Site Info :
Site location & type
Antenna azimuth
PCI
PCI 318 & PCI 321 have the same mod3
i.e. 0.
Solution: Change PCI 321 to 322 and PCI
322 to 321.
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Root Sequence Index (RSI) Planning Review  RSI Collision
Site Info :
Site location & type
Antenna azimuth
Root Sequence Index
Root Sequence Index 100 collisions.
Solution :
Change Root Sequence Index
LNCEL 394 from 100 to 230.
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© Nokia Siemens Networks 2013
of
0.00
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© Nokia Siemens Networks 2013
RNL, eNB init (M8006C12)
TNL, eNB init (M8006C14)
OTH, eNB init (M8006C13)
RNL, EPC init (M8006C8)
OTH, EPC init (M8006C9)
06.18.2012
06.17.2012
06.16.2012
06.15.2012
06.14.2012
65.00
2.00
1.60
1.40
1.00
0.60
0.40
0.00
1.80
6,000
5,000
1.20
4,000
0.80
3,000
2,000
1,000
0.20
0
-120
-15
-130
-20
-Possible external interference.
-Low SINR.
-Very high Max. PUSCH RSSI i.e. > -40 dBm.
06.24.2012 21:00:00
06.24.2012 18:00:00
06.24.2012 15:00:00
06.24.2012 12:00:00
06.24.2012 09:00:00
06.24.2012 06:00:00
06.24.2012 03:00:00
06.24.2012 00:00:00
06.23.2012 21:00:00
06.23.2012 18:00:00
06.23.2012 15:00:00
06.23.2012 12:00:00
06.23.2012 09:00:00
06.23.2012 06:00:00
06.23.2012 03:00:00
06.23.2012 00:00:00
-30
06.22.2012 21:00:00
Max. RSSI for PUSCH
06.22.2012 18:00:00
06.22.2012 15:00:00
06.22.2012 12:00:00
06.22.2012 09:00:00
06.22.2012 06:00:00
06.22.2012 03:00:00
06.22.2012 00:00:00
06.21.2012 21:00:00
06.21.2012 18:00:00
06.21.2012 15:00:00
06.21.2012 12:00:00
06.21.2012 09:00:00
06.21.2012 06:00:00
06.21.2012 03:00:00
Avg. RSSI for PUSCH
06.21.2012 00:00:00
06.20.2012 21:00:00
06.20.2012 18:00:00
06.20.2012 15:00:00
-70
06.20.2012 12:00:00
-60
06.20.2012 09:00:00
06.20.2012 06:00:00
06.20.2012 03:00:00
06.20.2012 00:00:00
06.19.2012 21:00:00
06.19.2012 18:00:00
06.19.2012 15:00:00
06.19.2012 12:00:00
06.19.2012 09:00:00
RRC Timer Expiry (LTE_5229b)
06.19.2012 06:00:00
5.00
06.19.2012 03:00:00
70.00
06.19.2012 00:00:00
10.00
06.18.2012 21:00:00
75.00
06.18.2012 18:00:00
80.00
06.18.2012 15:00:00
15.00
06.18.2012 12:00:00
85.00
06.18.2012 09:00:00
20.00
06.18.2012 06:00:00
95.00
06.18.2012 03:00:00
25.00
06.18.2012 00:00:00
90.00
RRC Timer Expiry [%]
100.00
E-RAB Drop Count per Cause
E-RAB Drop Rate (LTE_5025b)
06.18.2012
06.17.2012
06.16.2012
06.15.2012
06.14.2012
06.13.2012
06.12.2012
06.11.2012
06.10.2012
06.09.2012
06.08.2012
06.07.2012
RRC Setup Success Rate [%]
RRC CSSR (LTE_5218c)
06.13.2012
06.12.2012
06.11.2012
06.10.2012
06.09.2012
06.08.2012
06.06.2012
60.00
06.07.2012
06.06.2012
E-RAB Drop Rate [%]
External UL Interference
0
Avg. SINR for PUSCH
30
-10
-20
25
High RSSI
20
-40
15
-50
10
Low SINR
5
-80
0
-100
-90
-5
-110
-10
External UL Interference
• Interference wave happens frequently
causing PRACH failure.
• CSSR and Call Drop are impacted.
• Handover toward LNCEL 64652 are also
impacted.
Source
LNBTS name
NL_BSbujeondoseokwanA0
NL_BSbujeondoseokwanA0
NL_BSbujeondoseokwanA0
NL_BSbujeondoseokwanA0
NL_BSbujeondoseokwanA1
NL_BSbujeondoseokwanA1
NL_BSbujeonrotaryB4
NL_BSbujeonrotaryB4
NL_BSseomyontaehwaA0
NL_BSseomyontaehwaA0
NL_BSseomyontaehwaA0
NL_BSseomyontaehwaA0
NL_BSseomyontaehwaA1
NL_BSseomyontaehwaA1
NL_BSseomyontaehwaA1
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LNCEL name
Target
LNBTS name
61 NL_BSbujeondoseokwanA2
62 NL_BSbujeondoseokwanA2
63 NL_BSbujeondoseokwanA2
65 NL_BSbujeondoseokwanA2
384 NL_BSbujeondoseokwanA2
385 NL_BSbujeondoseokwanA2
5252 NL_BSbujeondoseokwanA2
5254 NL_BSbujeondoseokwanA2
70 NL_BSbujeondoseokwanA2
71 NL_BSbujeondoseokwanA2
72 NL_BSbujeondoseokwanA2
75 NL_BSbujeondoseokwanA2
410 NL_BSbujeondoseokwanA2
412 NL_BSbujeondoseokwanA2
413 NL_BSbujeondoseokwanA2
LNCEL name
64652
64652
64652
64652
64652
64652
64652
64652
64652
64652
64652
64652
64652
64652
64652
HO Attempt HO Success Rate
9961
9703
2
2
7458
544
872
11
22873
11014
3726
101
2
13
5
83.09
79.72
100
50
60.78
95.59
96.79
100
97.7
91.39
99.44
99.01
50
92.31
40
LNADJ Management
 Addition of LNADJ needs to be added by NetAct in bi-directional way.
 Number of LNADJ needs to be managed and monitored.
 Deletion of LNADJ needs to be checked in both direction :
• No outgoing handover attempt
• No incoming hanodver attempt
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Wrong LNADJ
 Wrong neighbour configured.
 Correction :
LNADJ Deletion : 131618  132234
LNADJ Addition : 131618   131110
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© Nokia Siemens Networks 2013
Irwan Radius / 07.03.2013
Parameter Optimization
RRC Setup Failures
The reason for the BTS not receiving the RRC Connection Setup Complete can be as follows:
DL – UE does not hear the contention resolution or RRC Connection Setup message
53% of analysed
RRC setup
failures are due
to DL problems
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© Nokia Siemens Networks 2013
Parameter Optimization
RRC Setup Failures
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Check List Summary
INPUT
PROBLEM
ACTION
Coverage Analysis/
Overshooting
Antenna Downtilting
Pilot Pollution
Parameter
Recommendation
EFFECT
RRC Setup Success Rate
Drive Test
Un-optimized
Parameter
RACH Success Rate
Adding Missing
Neighbour
E-RAB Drop Rate
Consistency Check
HO Success Rate
PCI Re-assignment
S1 HO Trigger  0
Missing Neighbour
Parameter
Inconsistency
Parameter
Dump
PCI Mod3 Violation
Root Sequence Index
Collision
Root Sequence Index
Re-assignment
Throughput
Unknown Problems
OSS
Statistics
PCI Confusion
Uplink Interference
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External Noise
Clean-up