Mobility Strategy
10/11/2020
Overall Camping Strategy – IDLE MODE
LTE(L1800 & L2100 Priority 6, L2600 Priority 7)
3G with priority 4
U2100 – F1
U900 – F0
U2100 – F2
U900 – F4
Current network scenario:
• We have five carriers on 3G.
• U900 F0: 2938
• U900 F4: 2963 (Very few sites)
• U2100 F1: 10687
• U2100 F2: 10712
• U2100 F3: 10737
• Primarily most of the sites in region use
U900 F0 & U2100 F1.
• Mainly one carrier on LTE, with
deployment of second carrier on L2100 ongoing.
U2100 – F3
10/13/2020
2
Overall Camping Strategy – IDLE MODE– Intra 3G
LTE(L1800 & L2100 Priority 6, L2600 Priority 7)
3G with priority 4
U2100 – F1
U900 – F0
U2100 – F2
U900 – F4
U2100 – F3
10/13/2020
UE limitations:
• 3G mobiles can search maximum two addition
frequencies at a time in both idle and dedicated.
Neighbor definition scenario:
• Considering above limitation we can configure
neighbors of only two frequencies for efficient
search and reselection.
• All sectors should be configured to search two
frequencies according to given figure. Priority is
given for co-located frequencies.
• U900 F0 is currently configured to search all
three U2100 frequencies and also F4 if available,
it is recommended to change according to
shown scenario.
• If F4 is configured on site then we can skip
F2 definition.
• These settings can be controlled by SIB11IND
flag in per neighbor basis.
Most of the network
Few sites in network
3
Overall Camping Strategy – IDLE MODE– Intra 3G
Below table highlights the recommended settings for cell access and reselection parameters.
UCELLSELRESEL
UCELLSELRESEL
•
•
•
•
QUALMEAS
QQUALMIN
QRXLEVMIN
IDLESINTRASEARCH
IDLESINTERSEARCH
SSEARCHRAT
U2100F1
CPICH_ECNO
-18
-58
5
4
1
U2100F2
CPICH_ECNO
-18
-58
5
4
1
U2100F3
CPICH_ECNO
-18
-58
5
4
1
U900F0
CPICH_ECNO
-18
-58
5
8
1
U900F4
CPICH_ECNO
-18
-58
5
8
1
UE can select a cell and access network if EcNO is above -18dB and RSCP is above -115dBm
Intra-frequency search starts at EcNo below -8dBm.
Inter-frequency search starts at EcNo below -10dBm. It is recommended to change this threshold for U900 to start search at EcNo below -2dBm. This way we can
push more users to U2100 which is supporting dual carrier HSDPA. U900 is mostly single carrier and dual band DC-HSDPA feature is not available in most of the
Ues. Thus our payload may increase.
IdleQOffset2Sn is also tuned to push more users to U2100, but without starting search this setting is not very useful. Details of relation level parameters shown in
coming slides.
10/13/2020
4
Overall Camping Strategy – DRD– Intra 3G
•
•
•
•
DRD is active in the network right now within U2100 layers.
DRD is not active from or towards U900.
TH2RNCH1 has measurement based DRD on, which increases the PS call setup time significantly.
Following are recommended settings for DRD.
UE Location Based DRD
& User number DRD
U2100 – F1
Blind DRD
U2100 – F2
Blind DRD
U2100 – F3
10/13/2020
U900 – F0 &
F4
It is highly recommended to enable location based multi-band
DRD feature in the RNCs. Currently this feature is not available
and needs to be purchased. Following are the advantages of this
feature:
• U900 to U2100 DRD can be done based on pathloss of
serving U900 cells. Thus ensuring successful DRD attempts
without degrading RAB SSR while also saving time by not
measuring target frequency.
• U2100 to U900 DRD can be done based on pathloss of
serving U2100 cells. Thus only sending endge users to U900,
ensuring maximum users take advantage of DC-HSDPA
function on U2100.
• Disable measurement based DRD switch in RNC and cell level.
• Details of parameter settings and switches are given in below
table.
5
Overall Camping Strategy – DRD– Intra 3G
MO
UCELLDRD
UDRD
UCORRMALGOSWITCH
Parameter
U2100F1
U2100F2
U2100F3
U900F0
U900F4
LDBDRDSWITCHHSDPA
ON
ON
ON
ON
ON
LdbDrdSwitchDCH
OFF
OFF
OFF
OFF
OFF
CodeBalancingDrdSwitch
OFF
OFF
OFF
OFF
OFF
UlLdbDrdSwitchDcHsdpa
OFF
OFF
OFF
OFF
OFF
HspaPlusSatisSwitch
ON
ON
ON
ON
ON
BasedUeLocDrdSwitch
ON
ON
ON
ON
ON
TrafficTypeForBasedUeLoc
RT-0&NRT-1
RT-0&NRT-1
RT-0&NRT-1
RT-0&NRT-1
RT-0&NRT-1
ServiceDiffDrdSwitch
OFF
OFF
OFF
OFF
OFF
LdbDRDOffsetHSDPA
5%
LdbDRDLoadRemainThdHSDPA
100%
BasedOnMeasHRetryDRDSwitch
OFF
LDBDRDCHOICE
UserNumber
DRSWITCH=DR_RAB_SING_DRD_SWITCH
100%
DRSWITCH=DR_RAB_COMB_DRD_SWITCH
0%
• Red highlighted above shows the new recommended settings.
• U900 DRD can only be activated if feature UE location based multi-band DRD is installed and activated.
10/13/2020
6
Load based mobility – Dedicated – Intra 3G
LDR Inter-frequency
BLINDHO
U2100 – F1
LDR Inter-frequency
BLINDHO
U2100 – F2
U900 – F0 &
F4
LDR Inter-frequency
Measured
U2100 – F3
• It is recommended to enable measurement based LDR from U900 to U2100.
• Within U2100 it is recommended to keep it blind.
10/13/2020
7
Load based mobility – Dedicated – Intra 3G
• It is recommended to enable measurement based LDR from U900 to U2100.
• Within U2100 it is recommended to keep it blind.
MOD UCELLLDR
Parameter
DlLdrFirstAction
DlLdrSecondAction
DlLdrThirdAction
DlLdrFourthAction
UlLdrFirstAction
UlLdrSecondAction
UlLdrThirdAction
U2100 F1
BERateRed
CodeAdj
InterFreqLDHO
/
BERateRed
InterFreqLDHO
/
U2100 F2
BERateRed
CodeAdj
InterFreqLDHO
/
BERateRed
InterFreqLDHO
/
U2100 F3
BERateRed
CodeAdj
InterFreqLDHO
/
BERateRed
InterFreqLDHO
/
U900 F0
BERateRed
CodeAdj
InterFreqLDHO
/
BERateRed
InterFreqLDHO
/
U900 F4
BERateRed
CodeAdj
InterFreqLDHO
/
BERateRed
InterFreqLDHO
/
INTERFREQLDHOMETHODSELECTION
BLINDHO
BLINDHO
BLINDHO
MEASUREHO
MEASUREHO
10/13/2020
8
Coverage based mobility – Intra 3G
Coverage based handovers from U2100 to U900 are recommended to be active in co-located sectors.
On frequency borders we can activate it to frequencies of neighbor sites as well.
Below scenario for collocated sectors is shown along with
MO
Parameter
recommended parameter setting on cell level
UCELLINTERFREQHOCOV
InterFreqReportMode
U2100 – F1
Inter Frequency Coverage Ho’s
U2100 – F2
U2100 – F3
10/13/2020
U900 – F0 & F4
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
UCELLINTERFREQHOCOV
InterFreqCsThd2dEcno
InterFreqR99PsThd2dEcno
InterFreqHThd2dEcno
InterFreqCsThd2fEcno
InterFreqR99PsThd2fEcno
InterFreqHThd2fEcno
InterFreqCsThd2dRscp
InterFreqR99PsThd2dRscp
InterFreqHThd2dRscp
InterFreqCsThd2fRscp
InterFreqR99PsThd2fRscp
InterFreqHThd2fRscp
TargetFreqCsThdEcno
TargetFreqR99PsThdEcno
TargetFreqHThdEcno
TargetFreqCsThdRscp
TargetFreqR99PsThdRscp
TargetFreqHThdRscp
HhoEcnoMin
HhoRscpMin
InterFreqMeasTime
IfHoFailNum
InterFreqHo2dEventType
Value
Periodic
-16
-18
-20
-14
-16
-18
-105
-110
-110
-102
-107
-107
-14
-16
-16
-102
-105
-105
-16
-102
10
3
ECNOANDRSCP
9
Overall Camping Strategy – Intra 3G
Based on above recommendations, following are recommended parameter settings between neighbor of different
frequencies for reselection and DRD.
FREQ/CARRIER
U2100F1
U2100F1
U2100F2
U2100F3
U2100F2
U2100F3
U900F0
U900F4
SIB11Ind: TRUE
IDLEQOFFSET2SN: 0
BLINDHOFLAG: TRUE
HOCOVPRIO: 0
SIB11Ind: FALSE
IDLEQOFFSET2SN: 0
BLINDHOFLAG: TRUE
HOCOVPRIO: 0
SIB11Ind: TRUE
IDLEQOFFSET2SN: 4
BLINDHOFLAG: FALSE
HOCOVPRIO: 2
SIB11Ind: FALSE
IDLEQOFFSET2SN: 4
BLINDHOFLAG: FALSE
HOCOVPRIO: 2
SIB11Ind: TRUE
IDLEQOFFSET2SN: 0
BLINDHOFLAG:TRUE
HOCOVPRIO: 0
SIB11Ind: TRUE
IDLEQOFFSET2SN: 4
BLINDHOFLAG: FALSE
HOCOVPRIO: 2
SIB11Ind: FALSE
IDLEQOFFSET2SN: 4
BLINDHOFLAG: FALSE
HOCOVPRIO: 2
SIB11Ind: TRUE
IDLEQOFFSET2SN: 4
BLINDHOFLAG: FALSE
HOCOVPRIO: 2
SIB11Ind: FALSE
IDLEQOFFSET2SN: 4
BLINDHOFLAG: FALSE
HOCOVPRIO: 2
SIB11Ind: FALSE
IDLEQOFFSET2SN: 0
BLINDHOFLAG: TRUE
HOCOVPRIO: 0
SIB11Ind: TRUE
IDLEQOFFSET2SN: 0
BLINDHOFLAG: TRUE
HOCOVPRIO: 0
SIB11Ind: FALSE
IDLEQOFFSET2SN: 0
BLINDHOFLAG: TRUE
HOCOVPRIO: 0
U900F0
SIB11Ind: TRUE
IDLEQOFFSET2SN: -4
BLINDHOFLAG: TRUE
DRDORLDRFLAG : TRUE
HOCOVPRIO: 0
SIB11Ind: TRUE
IDLEQOFFSET2SN: -4
BLINDHOFLAG: TRUE
DRDORLDRFLAG : TRUE
HOCOVPRIO: 0
SIB11Ind: FALSE
IDLEQOFFSET2SN: -4
BLINDHOFLAG: TRUE
DRDORLDRFLAG :: TRUE
HOCOVPRIO: 0
U900F4
SIB11Ind: TRUE
IDLEQOFFSET2SN: -4
BLINDHOFLAG: TRUE
DRDORLDRFLAG :: TRUE
HOCOVPRIO: 0
SIB11Ind: FALSE
IDLEQOFFSET2SN: -4
BLINDHOFLAG: TRUE
DRDORLDRFLAG :: TRUE
HOCOVPRIO: 0
SIB11Ind: FALSE
IDLEQOFFSET2SN: -4
BLINDHOFLAG: TRUE
DRDORLDRFLAG :: TRUE
HOCOVPRIO: 0
10/13/2020
SIB11Ind: TRUE
IDLEQOFFSET2SN: 0
BLINDHOFLAG: TRUE
DRDORLDRFLAG : FALSE
HOCOVPRIO: 0
SIB11Ind: TRUE
IDLEQOFFSET2SN: 0
BLINDHOFLAG: TRUE
DRDORLDRFLAG :: FALSE
HOCOVPRIO: 0
10
Overall Camping Strategy – 3G to LTE
Overall we have four layers on LTE. Most of the network is covered by L1800 and recently new rollout of L2100 has started.
L2600 also exists in some areas. Following are the priorities and parameter settings for each layer defined on 3G:
LTE RSRP > -110dBm
Reselection to LTE
LTE
UMTS
L1800/L2100/L2600
(F1,F2,F3, F0, F4)
Fast Return to LTE
NE
MML Command
Parameter Name
L1800
L2600
L2100
Cell
UCELLNFREQPRIOINFO
EARFCN
1650
3025
325/350
Cell
UCELLNFREQPRIOINFO
NPRIORITY
6
7
6
Cell
UCELLNFREQPRIOINFO
THDTOHIGH
5 (10dBm)
5 (10dBm)
5 (10dBm)
Cell
UCELLNFREQPRIOINFO
EQRXLEVMIN
-60(-120dBm)
-60(-120dBm)
-60(-120dBm)
Cell
ADD UCELLSELRESEL
CELLFACHPRIORESELSWITCH
ON
ON
ON
ADD UCELLSIBSWITCH
SIBCFGBITMAP
SIB19-1
SIB19-1
SIB19-1
10/13/2020
Cell
11
Overall Camping Strategy – 3G to LTE Fast REturn
Following parameters related to fast return from 3G to LTE are also recommended:
NE
MML Command
Parameter Name
Recommend Value
RNC
SET UCORRMALGOSWITCH
HoSwitch
HO_UMTS_TO_LTE_FAST_RETURN_SWITCH-1
Cell
ADD UCELLHOCOMM
FastReturnToLTESwitch
HO_UMTS_TO_LTE_FAST_RETURN_SWITCH-1
RNC
SET UCORRMALGOSWITCH
PerfEnhanceSwitch3
PERFENH_PS_FAST_RETURN_LTE_SWITCH-1
Cell
ADD UCELLHOCOMM
FastReturnToLTESwitch
PERFENH_PS_FAST_RETURN_LTE_SWITCH-1
RNC
SET UCORRMALGOSWITCH
HoSwitch2
HO_U2L_BASE_UE_LTE_MEAS_CAP_SWITCH-1
RNC
SET URRCTRLSWITCH
OptimizationSwitch6
U2L_CSFB_FAST_RETURN_PROC_OPTI_SWITCH-1
RNC
SET UCORRMPARA
PerfEnhanceSwitch7
PERFENH_CS_ONLY_MEAS_FAST_RETURN_SWITCH-1
RNC
SET UCORRMALGOSWITCH
HoSwitch2
HO_IUR_U2L_HO_SWITCH-1
RNC
SET UCORRMPARA
PerfEnhanceSwitch7
PERFENH_FAST_RETURN_OPT_SWITCH-1
•
UMTS to LTE Fast return is enabled on RNC Level.(It is recommended to add cell level control for
this feature. For eg A UE did CSFB to a 3G Cell & move away from LTE Coverage , in that case after
release the call UE will keep on searching the LTE service during this time UE cannot start a call or be
paged)
10/13/2020
12
Overall Camping Strategy – 3G to LTE Redirection
Currently there is no feature of redirection from 3G to LTE is available for non-CSFB users. If a user in in PS mode or connected
mode it cannot be redirected to LTE until it finishes it’s session and move to idle mode. It is therefore strongly recommended to
purchase and install one of the following features to enhance user experience and LTE Traffic Share.
• Service Based PS Redirection to LTE. (Priority 1): This feature allow us to redirect all LTE capable mobiles to LTE in following
scenarios:
• Normal call release
• Iucs release
• Iupsrelease
• Best cell change
• RB Reconfiguration
• Low activity
• Periodic redirection.
• Coverage Based PS Redirection to LTE: This feature allow us to redirect to LTE in case of low coverage of 3G. Thresholds
defining low coverage for 3G can be tuned and we can set it aggressively to redirect more users.
• Load Based PS Redirection to LTE: This feature allow us to redirect to LTE in case of high load on 3G. Load thresholds can be
tuned to control.
10/13/2020
13
Overall Camping Strategy – LTE
•
•
•
•
Current scenario has most of the network with single carrier, either L1800 or L2100.
Recently second carrier is being integrated to have both L1800 and L2100 layers.
In dual carrier sites we have 15Mhz on L2100 and 10MHz on L1800.
This presentation discuss how inter-frequency traffic is balanced and HO threshold to 3G are configured.
LTE Priority 6
L1800
L1800
L2100
L2100
3G Priority 4
10/13/2020
14
Overall Camping Strategy – Intra LTE Idle
•
•
•
•
•
•
Both layers has same priority.
Both layers can be access if RSRP is better -120dBm and RSRQ is better than -18dB
It is recommended to remove RSRQ threshold and use only RSRP for cell access
L1800 is 10MHz while L2100 is 15MHz
Below figure shows the strategy to push more users on L2100 and keep relatively lower users on L1800 in idle mode.
Mainly search threshold is currently more relax on L1800, it is recommended to make qOffsetFreq as highlighted to take
more advantage from higher BW on L2100.
• L1800 starts search when it’s level drops below -100dB and reselects to
Start Search < -100dBm
Qhyst = 3dB
L1800
qOffsetFreq < -3
Below table shows recommended parameter settings for idle mode:
L1800
L2100
Start Search < -114dBm
qHyst = 5dB
10/13/2020
•
LTE Priority 6
qOffsetFreq < 2
L2100
•
L2100 if L2100 level is 3dB better than L1800.
• If qOffsetFreq is applied, L2100 can be reselected even with same level
as L1800.
L2100 starts search when it’s level drops below -114dB and reselects to
L1800 if L1800 level is 5dB better than L2100
• If qOffsetFreq is applied, L1800 can be selected if it is 7dB better than
L2100.
MO
CELLRESEL
CELLRESEL
CELLRESEL
CELLRESEL
CELLRESEL
CELLRESEL
EutranInterNFreq
PARAMETER
QRXLEVMIN
SIntraSearch
SNonIntraSearch
Qhyst
QQualMinCfgInd
QQualMin
qOffsetFreq
L1800
-60
25
10
DB3_Q_HYST
NOT_CFG
-3
L2100
-60
25
3
DB5_Q_HYST
NOT_CFG
152
Overall Camping Strategy – Intra LTE dedicated
• Both layers has same priority.
• Both layers are currently using event A4 for coverage based handover.
• Connected mode priority is also same for both layers, i.e. 6.
Start Search < -113dBm
Stop Search > -111dBm
L1800
HO if L21 > -113dBm
L2100
LTE Priority 6
L1800
HO if L18 > -109dBm
L2100
Start Search < -117dBm
Stop Search > -115dBm
10/13/2020
•
L1800 starts search when it’s level drops below -113dBm and HO to L2100 if
L2100 level is better than -113dBm.
•
L2100 starts search when it’s level drops below -117dBm and HO to L1800 if
L1800 level is better than -109dBm.
•
Below table shows recommended parameter settings for dedicated mode:
MO
INTERFREQHOGROUP
INTERFREQHOGROUP
INTERFREQHOGROUP
INTERFREQHOGROUP
INTERFREQHOGROUP
EutranInterNFreq
EutranInterNFreq
PARAMETER
InterFreqHoA2ThdRsrp
InterFreqHoA1ThdRsrp
InterFreqHoA1A2Hyst
InterFreqHoA4Hyst
InterFreqHoA4ThdRsrp
qOffsetFreqConn
InterFreqHoEventType
L1800
-112
-110
2
2
-114
-3
EventA4
L2100
-116
-114
2
2
-110
2
EventA4
16
Overall Camping Strategy – Intra LTE MLB
• MLB based on both PRB and user number should be enabled.
• Trigger conditions for L1800 are more relax compare to L2100 to push users to L2100
MLB trigger:
PRB Util > 40%
User > 25
LTE Priority 6
L1800
HO if L21 > -113dBm
L2100
L1800
MLB starts for L1800 if number of users exceed 25 or PRB utilization
increased above 40%. Handover to L2100 will only happen if it’s load is 5%
lower than L1800 and RSRP is better than -113dBm
•
MLB starts for L2100 if number of users exceeds 35 or PRB utilization
increased above 55%. Handover to L1800 will only happen if it’s load is 10%
lower than L2100 and RSRP is better than -109dBm
•
Below
MO table shows recommended
PARAMETER parameter settings
L1800 for MLB:
HO if L18 > -109dBm
L2100
MLB trigger:
PRB Util > 55%
User > 35
10/13/2020
•
CELLMLB
CELLMLB
CELLMLB
CELLMLB
CELLMLB
INTERFREQHOGROUP
MlbTriggerMode
InterFreqMlbThd
LoadOffset
InterFreqMlbUeNumThd
MlbUeNumOffset
InterFreqLoadBasedHoA4ThdRsrp
CELLMLB
LoadDiffThd
L2100
PRB_OR_UE_NUMBER PRB_OR_UE_NUMBER
30
50
5
5
20
30
5
5
-114
-110
5
15
17
Overall Camping Strategy – LTE to 3G
• 3G frequencies priority is lower than LTE
• Therefore in idle mode redirection can only happen when levels are lower than ThrshServLow
Search Start < -116dBm
LTE Priority 6
L1800
L1800
L2100
L2100
Search Start < -116dBm
•
3G search starts when LTE RSRP falls below -116dBm
•
Reselection to 3G only happens when RSCP is better than -100dBm and EcNo
is better than -18dB
•
Below table shows recommended parameter settings for Idle mode:
MO
CELLRESEL
UTRANNFREQ
UTRANNFREQ
UTRANNFREQ
UTRANNFREQ
PARAMETER
ThrshServLow
QRXLEVMIN
ThreshXLow
QQualMin
ThreshXLowQ
L1800
2
-60
10
-22
2
L2100
2
-60
10
-22
2
3G RSCP > -100dBm
3G EcNo > -18dB
3G Priority 4
10/13/2020
18
Overall Camping Strategy – LTE to 3G
• Following figure and table shows start/stop threshold for IRAT HO to 3G.
Search Start < -120dBm
Search Stop > -117dBm
LTE Priority 6
L1800
L1800
L2100
L2100
Search Start < -120dBm
Search Stop > -117dBm
•
3G search starts when LTE RSRP falls below -120dBm
•
Redirection to 3G only happens when RSCP is better than -101dBm
•
Below table shows recommended parameter settings for Idle mode:
MO
INTERRATHOCOMMGROUP
INTERRATHOCOMMGROUP
INTERRATHOCOMMGROUP
INTERRATHOUTRANGROUP
INTERRATHOCOMM
INTERRATHOCOMM
INTERRATHOCOMM
PARAMETER
InterRatHoA2ThdRsrp
InterRatHoA1ThdRsrp
InterRatHoA1A2Hyst
InterRatHoUtranB1ThdRscp
InterRatHoUtranB1MeasQuan
InterRatHoA1A2TrigQuan
InterRatHoEventType
L1800
-119
-118
2
-101
RSCP
RSRP
EventB1
L2100
-119
-118
2
-101
RSCP
RSRP
EventB1
3G RSCP > -101dBm
3G Priority 4
10/13/2020
19
10/13/2020
20