Mobility strategy and traffic steering

1. MOBILITY & traffic steering
STRATEGY review
ASHITEI ASHIBOE-MENSAH MMEA MS NDO AFRICA 2020-02-10

2. Ericsson Internal | 2018-02-21
GSMHIGH-LEVELSUMMARY
➢ Add Missing UMFIs for Co-located 3G cells
➢ Add missing EARFCNs for Co-located 4G cells
➢ Legacy Cell Reselection
▪ QSI (7 = ALWAYS)
▪ FDDQMIN (6 = -14dB)
▪ FDDQOFF (0 = INFINITY)
▪ FDDRSCPMIN (4/3 = -106/-108 dBm)
➢ Priority-Based Cell Reselction
▪ PRIOCR
▪ RATPRIO
▪ FASTRETLTE
▪ FASTRET3G
▪ COVERAGEE (GOOD)
▪ COVERAGEU (GOOD)
▪ HPRIOTHR (for 4G)(4 = 8 dB)
▪ QRXLEVMINE (8 = -124 dBm)
▪ HPRIOTHR (for 3G)(3 = 6 dB)
▪ QRXLEVMINU (2 = -115 dBm)

3. Ericsson Internal | 2018-02-21
WCDMAHIGH-LEVELSUMMARY
➢ Add missing EutranFreqRelations for Co-located 4G cells
➢ Legacy Cell Reselection
▪ qOffset1sn (50 dB for GsmRelations)
▪ qOffset2sn
▪ qHyst1 (4 dB)
▪ qHyst2 (2 dB)
▪ sRatSearch (2 dB)
➢ Priority-Based Cell Reselction
▪ EutranFreqRelation.CellReselectionPriority
▪ EutranFreqRelation.threshHigh (6 dB)
▪ EutranFreqRelation.qRxLevmin (-124 dBm)
➢ dlCodePwrCm (usedFreqThresh2dEcno = -24 dB)
➢ releaseRedirectEutraTriggers (Manage Fast Return from 3G to 4G)
➢ UeRc Settings (Prevent PS Traffic from moving from 3G to 2G)
▪ gsmHoAllowed (0 for PS-Only UeRcs)
▪ ifhoAllowed (0 for PS-Only UeRcs)
▪ serviceOffset2dEcno (-20 for PS-Only UeRcs)
▪ serviceOffset2dRscp (-50 for PS-Only UeRcs)
➢ RabCombinations (Disable Higher-order R99 RABs)
➢ IFLS (Proper Load Balancing between 3G Layers)
▪ iflsHyst (10/5)
▪ hsIflsMarginUsers (50 for U900 cells)
▪ hsIflsThreshUsers
▪ iflsCpichEcnoThresh (-16 dB)
▪ pathlossThreshold (110 for U900; 130 for U2100)

4. Ericsson Internal | 2018-02-21
LTEHIGH-LEVELSUMMARY
➢ Pre-Requisite Mobility Features
▪ WCDMA Session Continuity / InterFreq Handover / MCPC / InterFreq Load Balancing
Idle Mode Mobility (See slide 6)
➢ Start IRAT (or Low Priority LTE Freq) Measurements in Idle Mode (-124 dBm)
(EUtranCellFdd.systeminformationblock3.sNonIntraSearch)
➢ Required Serving LTE Cell Threshold for Idle Mode Fallback to WCDMA (-124 dBm) (EUtranCellFdd.threshServingLow)
➢ Required Target LTE Cell Level from LLow to LHi (-118 dBm) (EUtranFreqRelation.threshXHigh)
➢ Required Target LTE Cell Level from LHi to LLow (-112 dBm) (EUtranFreqRelation.threshXLow)
Connected Mode Mobility (See slides 7,8 & 9)
➢ MCPC A1 Good Coverage (LLow = -110 dBm; LHi = -113 dBm)
➢ MCPC A2 Inner Search (LLow = -114 dBm; LHi = -117 dBm)
➢ MCPC A5 Threshold 1 (LLow = -114 dBm; LHi = -117 dBm)
➢ MCPC A5 Threshold 2 (LLow = -115 dBm; LHi = -110 dBm)
➢ MCPC A2 Outer Seacrh (-122 dBm for both LLow & LHi)
➢ MCPC B2 Threshold 1 (-122 dBm for both LLow & LHi)
➢ MCPC B2 Threshold 2 (-107 dBm for target WCDMA Cell)
➢ MCPC Critical Coverage (-131 dBm for both LLow & LHi)
➢ IFLB-Triggered A5 Threshold 1 (LLow = -45 dBm; LHi = -114 dBm)
➢ IFLB-Triggered A5 Threshold 2 (LLow = -116 dBm; LHi = -105 dBm)
➢ IFLB Functionality Settings
▪ LoadBalancingFunction.lbCeiling
▪ LoadBalancingFunction.lbThreshold
▪ EUtranCellFDD.cellSubscriptionCapacity
▪ QciProfilePredefined.qciSubscriptionQuanta

5. SAMPLe 4G Mobility & load balancing
findings & proposed STRATEGY

6. Ericsson Internal | 2018-02-21
Current: L1800 RSRP < -116/-102 dBm
(Proposed: L800 < -124 dBm)
Current: L2600 RSRP < -116/-102 dBm
(Proposed: L2600 < -126 dBm)
3G
3G:qRxLevMin : -115 dBm 4G:qRxLevMin=-122 (Proposed=-124)
qQualMin: Current = -18 dB; Proposed = -20 dB
4G
Mobility Overview Proposal – Idle Mode
Reselection or
Redirection
Current:
L1800 RSRP > -112/-114/-118
L2600 RSRP > -112
(Proposed: > -118)
Target
Priority
3/2
LEGEND
7/6
L2600=20 MHz & L1800=10 MHz
Current: qRxLevMin : -120/-122 dBm
Proposed qRxLevMin: L2600=-126; L1800=-124
Current:
All WCDMA RSCP/EcNo values
Current: WCDMA RSCP > -113/-111 dBm
(Proposed: WCDMA RSCP > -110 dBm)
2G
3G: qRxLevMin : -115 dBm
4$: qRxLevMinE: -124 dBm
1
L2600
L1800
RSRP < -102/-116
(Proposed: < -126)
RSRP > -112/-116
(Proposed: > -118)
RSRP : All Levels
6
U2100 F1 & F2
U900 F3
Priority : 3
Priority : 3 (2)
qOffset2sn
Current: 0 dB
qOffset2sn
Current: 0 dB
(Proposed: 3dB)
(Proposed: 0dB)
FASTRETLTE (G2L)
Old: RSRP > -110 dBm
Proposed: RSRP > -116 dBm
gsmRelation.qOffset1Sn
Current = 7 dB
(Proposed: 50 dB)
Current: EcNo/RSCP
> -12 dB/-102 dBm
Proposed: EcNo/RSCP
> -14 dB/-106 dBm
FASTRET3G (G2U)
3G RSCP > -111 dBm
Current: Measure WCDMA @
RSRP < -118/-110 dBm
Proposed: RSRP < -124 (L1800)
Proposed: RSRP < -126 (L2600)
Current: Measure GSM @
RSCP < -116 dB
(Proposed: RSCP < -118 dB)
7
RSRP < -114/-120
(Proposed: < -112)
Measure L1800:
Current: < -118/-110
(Proposed: < -120/-126) X

7. Ericsson Internal | 2018-02-21
ConnectedMode–TELMAMD
L1800MCPCThresholds
Inner Search zone
Outer Search zone
Good Coverage
Proposed A1 Thresh = -110
(Current = -112 )
Proposed A2 Inner Search Thresh = -114
(current = -116 )
L1800 MCPC
Proposed Outer Search Thresh = -122
(Current = -116 )
Proposed Critical Cov = -131
(Current= -121/-141 )
A5 Threshold 1 (Source Cell):
Current: < -111 dBm
Proposed: < -114 dBm
A5 Threshold 2 (Target Cell):
Current: > -109 dBm
Proposed: > -115 dBm
B2 Threshold 1 (Source Cell):
Current: < -115 to -122 dBm
Proposed: < -122 dBm
B2 Threshold 2 (Target Cell):
Current: > -109 to -116 dBm
Proposed: > -107 dBm
A5
B2
L2600
W2100
L1800
G900
U900

8. Ericsson Internal | 2018-02-21
ConnectedMode–TELMAMD
L2600MCPCThresholds
Inner Search zone
Outer Search zone
Good Coverage
Proposed A1 Thresh = -113
(Current = -112 )
Proposed A2 Inner Search Thresh = -117
(current = -116 )
Proposed Outer Search Thresh = -122
(Current = -116 )
Proposed Critical Cov = -131
(Current= -121/-141 )
A5 Threshold 1 (Source Cell):
Current: < -111 dBm
Proposed: < -117 dBm
A5 Threshold 2 (Target Cell):
Current: > -109 dBm
Proposed: > -110 dBm
B2 Threshold 1 (Source Cell):
Current: < -115 to -122 dBm
Proposed: < -122 dBm
B2 Threshold 2 (Target Cell):
Current: > -109 to -116 dBm
Proposed: > -107 dBm
A5
B2
L2600 MCPC
L2600
W2100
L1800
G900
U900

9. Ericsson Internal | 2018-02-21
4G – L2600
Mobility Overview Proposal: LTE Inter-Frequency Load Balancing
(Connected Mode)
Inter-Freq -
Load Balancing
4G – L1800
Current: RSRP > -43
(Proposed: > -116)
Current: RSRP < -45
(Proposed: < -118 )
Current: RSRP > -43
(Proposed: >-105 )
LEGEND
Current: RSRP < -45
(Proposed: < -45 )

10. SAMPLE 3G Mobility & LOAD SHARING
proposed STRATEGY

11. Ericsson Internal | Airtel Gabon Camping Strategy | 2018-09-27 | Page 11
Possible layer scenarios
to be implemented when the full u900 layer is rolled out
U2100-F1
GSM
U2100-F2
LTE
U2100-F1
GSM
U2100-F2
LTE
U2100-F1
GSM
LTE
GSM
Scenario 1
U2100-F3
U900-F4
U900-F4 U900-F4 U900-F4
Scenario 2 Scenario 3 Scenario 4
U2100-F1

12. Ericsson Internal | Airtel Gabon Camping Strategy | 2018-09-27 | Page 12
Scenario 1 = Gsm+u900(1C)+U2100(3C)+L1800(1C)+L2600(1C)
U2100 F2 (P3)
IF-GSM-PREF
U2100 F1 (P3)
IF-GSM-PREF
U2100 F2 (P3)
IF-GSM-PREF
U2100 F1 (P3)
IF-GSM-PREF
IFHO
IRAT
INTRA-
FREQ HO &
RE-SELECTION
GSM (P1) GSM (P1)
U900 F4 (P2)
IF-GSM-PREF
U900 F4 (P2)
IF-GSM-PREF
U2100 F3 (P3)
IF-GSM-PREF
U2100-F3 (P3)
IF-GSM-PREF
Inter-Freq + GSM Relations
F1 → F2+U900 + IRAT (Same site + Neighbour site)
F2 → F3+U900 + IRAT (Same site + Neighbour site)
F3 → F1+U900 + IRAT (Same site + Neighbour site)
U900 → F1+F2 + IRAT (Same site + Neighbour site)
IRAT
HO
IRAT
HO
L800 (P6) LTE (P7/P7)
IRAT
HO
IRAT
HO
IRAT IDLE
RE-SELECTION
RE-SELECTION RE-SELECTION
RE-SELECTION
RE-SELECTION
LTE (P7/P6)
CSFB CSFB
CSFB to WCDMA
Intra-Freq Relations (2-way)
F1 → F1 (Same site + Neighbour site)
F2 → F2 (Same site + Neighbour site)
F3 → F3 (Same site + Neighbour site)
U900 → U900 (Same site + Neighbour site)

13. Ashitei Ashiboe-Mensah | 2019-01-24 | Movicel Angola Reselection, Mobility & Traffic Steering Audit | | Page 13
Scenario 2 = GSM+u900(1C)+U2100(2C)+L1800(1C)+L2600(1C)
U2100 F2 (P3)
IF-GSM-PREF
U2100 F1 (P3)
IF-GSM-PREF
U2100 F2 (P3)
IF-GSM-PREF
U2100 F1 (P3)
IF-GSM-PREF
IFHO
IRAT
INTRA-
FREQ HO &
RE-SELECTION
GSM (P1) GSM (P1)
U900 F3 (P2)
IF-GSM-PREF
U900 F3 (P2)
IF-GSM-PREF
Inter-Freq & GSM Relations
F1 → F2+U900 + IRAT (Same site + Neighbour site)
F2 → F1+U900 + IRAT (Same site + Neighbour site)
U900 → F1+F2 + IRAT (Same site + Neighbour site)
IRAT
HO
IRAT
HO
L800 (P6) LTE (P7/P6)
IRAT
HO
IRAT
HO
IRAT IDLE
RE-SELECTION
RE-SELECTION RE-SELECTION
RE-SELECTION
RE-SELECTION
LTE (P7/P6)
CSFB CSFB
CSFB to WCDMA
Intra-Freq Relations (2-way)
F1 → F1 (Same site + Neighbour site)
F2 → F2 (Same site + Neighbour site)
U900 → U900 (Same site + Neighbour site)

14. Ericsson Internal | Airtel Gabon Camping Strategy | 2018-09-27 | Page 14
Scenario 3 = GSM+u900(1C)+U2100(1C)+L1800(1C)+L2600(1C)
U2100 F1 (P3)
IF-GSM-PREF
U2100 F1 (P3)
IF-GSM-PREF
IFHO
IRAT
INTRA-
FREQ HO &
RE-SELECTION
GSM (P1) GSM (P1)
U900 F2 (P2)
IF-GSM-PREF
U900 F2 (P2)
IF-GSM-PREF
Inter-Freq + GSM Relations
F1 → U900 + IRAT (Same site + Neighbour site)
U900 → F1 + IRAT (Same site + Neighbour site)
IRAT
HO
IRAT
HO
L800 (P6) LTE (P7/P6)
IRAT
HO
IRAT
HO
IRAT IDLE
RE-SELECTION
RE-SELECTION RE-SELECTION
RE-SELECTION
RE-SELECTION
LTE (P7/P6)
CSFB CSFB
CSFB to WCDMA
Intra-Freq Relations (2-way)
F1 → F1 (Same site + Neighbour site)
U900 → U900 (Same site + Neighbour site)

15. Ericsson Internal | Airtel Gabon Camping Strategy | 2018-09-27 | Page 15
Scenario 4 = gsm+u900(1C) + U2100(1C)
U2100 F1 (P3)
IF-GSM-PREF
U2100 F1 (P3)
IF-GSM-PREF
IFHO
IRAT
INTRA-
FREQ HO &
RE-SELECTION
GSM (P1) GSM (P1)
U900 F2 (P2)
IF-GSM-PREF
U900 F2 (P2)
IF-GSM-PREF
Inter-Freq + GSM Relations
F1 → U900 + IRAT (Same site + Neighbour site)
U900 → F1 + IRAT (Same site + Neighbour site)
IRAT
HO
IRAT
HO
IRAT IDLE
RE-SELECTION
RE-SELECTION
RE-SELECTION
CSFB to WCDMA
Intra-Freq Relations (2-way)
F1 → F1 (Same site + Neighbour site)
U900 → U900 (Same site + Neighbour site)

16. Ashitei Ashiboe-Mensah | 2019-01-24 | Movicel Angola Reselection, Mobility & Traffic Steering Audit | | Page 16
Sib11 congestion –
precautions to take
SIB11
- SIB12 Indicator
- FACH Measurement Occasion Information
- Measurement Control System Information
- Use of HCS
- Cell Selection and Reselection Criteria
- Intra-frequency measurement system information
- Intra-frequency cell info list
…
- Inter-frequency measurement system information
- InterFrequency Cell Info List
…
- Inter-RAT measurement system information
-Inter Rat Cell Info List
…
❑ Example of safe number to avoid SIB11 issues:
➢ max 22 INTRA, max 20 INTER, max 16 GSM
➢ Total of 58 max neighbours

17. Ashitei Ashiboe-Mensah | 2019-01-24 | Movicel Angola Reselection, Mobility & Traffic Steering Audit | | Page 17
Compressed mode strategy
Downlink Code Power based Compressed Mode (W15B onwards)
Background
› Operator with growing/heavy HSPA traffic want to avoid unnecessary
compressed mode and do not want to move connections to GSM if not
needed
Description
› Introduces a new trigger for compressed mode, Downlink Radio Link
Code Power
– Replaces/ reduces the need for Ec/N0 as trigger for Compressed Mode
Benefits
› Reducing unnecessary triggering of Compressed Mode gives:
– More WCDMA coverage
– Reduced system load
– Less IRAT Handovers
RBS
Node B
GSM Coverage
WCDMA Coverage
Area where no compressed mode
is triggered when Ec/No based
trigger is replaced by Downlink
Code Power Based CM

18. Ashitei Ashiboe-Mensah | 2019-01-24 | Movicel Angola Reselection, Mobility & Traffic Steering Audit | | Page 18
Feature Recommendations
➢ Activate Feature DCH/EUL Load Balancing (UL congested cells won’t be target of LS)
➢ Disable Feature DCH Load Sharing (Prevent Voice calls from being targeted by IFLS)
➢ Activate Feature FAJ 121 1880 HSDPA IFLS Capability and Priority Handling
Proposed 3G load sharing strategy
Overall Proposed Strategy
➢ Activate HS-IFLS (HspaLoadSharing) on all 3 WCDMA Layers
➢ Define Bi-Directional Co-Sector Coverage Relations in all WCDMA Layers
➢ Control load sharing between layers by tuning HS-IFLS parameters
▪ iflsHyst → (Lower the Hysteresis load criterion between the more loaded & the less loaded cells)
▪ hsIflsMarginUsers → (make U900 look more loaded than U2100 in reality before even starting HS-IFLS Evaluation)
▪ hsIflsThreshUsers → (Lower the HS-IFLS algorithm trigger threshold so as to increase the frequency of off-loading from U900)
▪ hsIflsSpeechMultiRabTrigg → (set to 0, so as to prevent Speech-inclusive MultiRabs from being targeted by HS-IFLS, thereby prevent possible dropped voice calls)
▪ iflsCpichEcnoThresh → Allow IFLS-triggered reconfigurations from FACH/URA to HSDPA only in good EcNo conditions
▪ iflsMode → Do not allow Up-switch Attempts to serve as HS-IFLS trigger on U900 cells towards U2100 cells (due to absence of pathloss checks during Up-switch attempts)
▪ pathlossThreshold → (make the pathloss criteria more strict for U900 than for U2100, thereby reduce probability of offloading traffic to U900)

19. Ashitei Ashiboe-Mensah | 2019-01-24 | Movicel Angola Reselection, Mobility & Traffic Steering Audit | | Page 19
U2100-F2
U2100-F1
HSIFLS
HS IFLS
U900-F3
F1 → F2 + U900
F2 → F1 + U900
U900 → F1 + F2
Source Target
F1 F2
F1 U900
U900 F1
U900 F2
F2 F1
F2 U900
HSDPA Interfrequency Load Sharing (2/3)
(HSdpa-IFLS)
LEGEND
➢Define Bi-Directional Co-Sector
Coverage Relations in all 3 Layers

20. Ericsson Internal | Airtel Gabon Camping Strategy | 2018-09-27 | Page 20
U2100-F2
U2100-F1
HSIFLS
HS IFLS
U900-F4
U2100-F3
F1 → F2 + F3 + U900
F2 → F1 + F3 + U900
F3 → F1 + F2 + U900
U900 → F1 + F2 + F3
Source Target
F1 F2
F1 F3
F1 U900
U900 F1
U900 F2
U900 F3
F2 F1
F2 F3
F2 U900
F3 F2
F3 F1
F3 U900
HSDPA Interfrequency Load Sharing (3/3)
(HSdpa-IFLS)
LEGEND
➢Define Bi-Directional Co-Sector
Coverage Relations in all 4 Layers

21. Ashitei Ashiboe-Mensah | 2019-01-24 | Movicel Angola Reselection, Mobility & Traffic Steering Audit | | Page 21
HSDPA Interfrequency Load Sharing (1/3)
(HSdpa-IFLS)
MO Parameter
Proposed
setting on RNC
Proposed setting
On U2100 cells
Propsoed setting
On U900 cells
Handover iflsHyst
10
(can be set = 5)
UtranCell hsIflsMarginUsers 0
50
(make U900 look 50% more loaded than in reality
before starting IFLS Evaluation)
UtranCell hsIflsThreshUsers 5 (can be set higher) 5 (can be set lower)
UtranCell hsIflsSpeechMultiRabTrigg
0
(Currently 326 cells = 1)
0
(Currently 56 cells = 1)
UtranCell iflsCpichEcnoThresh -14 (can be tuned further) -14 (can be tuned further)
UtranCell iflsMode
2
(RAB_EST_AND_UPSWITCH_ATT)
0
(RAB_EST)
(for more aggressive IFLS, set to 2)
UtranCell pathlossThreshold 130 110 (can be tuned further)
Eul pathlossThresholdEulTti2 135 135
› UE movement at Load Sharing is performed through Blind (no measurements) handover, and hence
there is a chance for failure
› If Blind HO fails, call isn’t dropped, it returns to source call => but this introduces delays in
establishment that would impact user experience, specially for typical bursty behaviours

22. Ashitei Ashiboe-Mensah | 2019-01-24 | Movicel Angola Reselection, Mobility & Traffic Steering Audit | | Page 22
› U2100 layer is Multi-Carrier Capable. To take full advantage of the MC capabilities, this feature
allows one to prioritize those U2100 carriers for the UEs that support MC, increasing overall
user experience and throughput
› But more importantly, it also adds an important improvement:
– hsIflsSpeechMultiRabTrigg switch takes effect when the feature is activated
– hsIflsSpeechMultiRabTrigg recommended to be set = OFF, else there is a risk of CS drops due to blind Handover
› If a user has setup a speech call in a cell, and then tries to setup a HS connection to speech+HS, the cell
parameter hsIflsSpeechMultiRabTrigg is checked to decide if HSDPA IFLS must trigger/evaluate or not.
› Recommended to license and activate feature, and set hsIflsSpeechMultiRabTrigg = OFF
› RncFeature=HsdpaIflsCapAndPrioHandling (must be ENABLED)
HSDPA IFLS Capability and Priority
Handling (W12b onwards)