LTE Parameters OPtimization Recommendations for Special Events(ERAN7)

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LTE Parameter Optimization Proposal for Festival Event Sites www.huawei.com

HUAWEI TECHNOLOGIES CO., LTD.

Contents Objective  List of recommended parameters to be Optimized

Objective  for Events Festival areas, there is a major activities during the holidays , So there is large number of users are concentrated in one area during those Events , Which reflect to have more & more LTE users  During those Events; we need to protect the safe operations of the LTE network & guarantee the normal use of LTE business users from a technical level  from this technical PPT document; recommend some parameters Optimization for those eNB sites which coverage Festival Events area.

List of recommended parameters to be Optimized

SRI Adaptive Switch Object Parameter

Activate SRI Adaptive Switch

MML Command

MOD GLOBALPROCSWITCH: SriAdaptiveSwitch=ON

Impact on Radio Network Performance

 If this parameter is set to ON, the eNodeB adjusts the SRI period based on the SRI algorithm so that the number of admitted UEs can reach the cell capacity. If this parameter is set to OFF, the maximum number of admitted UEs depends on the user-defined SRI period.

PUCCH resource adjustment switch Object Parameter

Activate PUCCH resource automatic adjustment Switch

MML Command

PucchAlgoSwitch=Pucc hSwitch-1

Impact on Radio Network Performance

If this switch is turned on, PUCCH resource adjustment achieves better utilization of PUCCH resources and reduces uplink control signaling overhead. When the PUCCH resources decrease, however, CQI resources may need to be reconfigured for a few UEs. The reconfiguration consumes certain downlink resources. If this switch is turned off, uplink control signaling overhead increases.

CQI adjustment switch Object Parameter

Activate CQI adjustment step vary switch

MML Command

Impact on Radio Network Performance

 If this switch is turned on, the IBLER convergence rate can be adjusted based MOD on site scenarios, increasing the CELLALGOSWITCH:CQIA downlink rate based on scenarios. DJALGOSWITCH=StepVa  If this switch is turned off, the IBLER rySwitch-1; convergence rate cannot be adjusted, decreasing the downlink rate based on scenarios.

Activate SRS Object Parameter

Activate SRS

MML Command

MOD SRSCFG: SrsCfgInd=ON;

Impact on Radio Network Performance

If this parameter is set to BOOLEAN_TRUE, SRS is supported, and higher performance gains are obtained in features depending on SRS measurements, such as beamforming (BF) and uplink frequency selection. However, the cell peak rate in the uplink decreases due to SRS overheads. If this parameter is set to BOOLEAN_FALSE, no SRS resource is available in the cell, and no UE is configured with SRS resources, and therefore the optimum cell peak rate in the uplink can be obtained. However, lower performance gains are obtained in features depending on SRS measurements.

Activate SRS Adaptive Period Object Parameter

MML Command

Impact on Radio Network Performance

If this parameter is set to ON, the eNodeB adaptively adjusts the SRS period for UEs that will access the cells Activate SRS MOD SRSADAPTIVECFG: under the eNodeB. The adjustment is adaptive period SrsPeriodAdaptive=ON; based on the load of SRS resources and achieves a tradeoff between the number of UEs served and network performance. If this parameter is set to OFF, the eNodeB uses a fixed SRS period for UEs that will access the cells under the eNodeB.

Set Adaptive RBG Allocation Strategy Object Parameter

MML Command

Impact on Radio Network Performance If this parameter is set to ROUND_DOWN, all allocated RBs are fully utilized, spectral efficiency is high, but cell throughput is relatively low.

Set Adaptive RBG Allocation Strategy

MOD CELLDLSCHALGO: LocalCellId=x, RbgAllocStrategy=ADAPTI VE;

 If this parameter is set to ROUND_UP, a few allocated RBs are not utilized, spectral efficiency is low, but cell throughput is relatively high. Compared with setting this parameter to ROUND_UP,  setting this parameter to ADAPTIVE does not waste RBs when the number of required RBGs is less than 1.

Set Adaptive Enhanced CFI Object Parameter

Set Adaptive Enhanced CFI

MML Command

MOD CELLPDCCHALGO:PdcchSy mNumSwitch=ECfiAdaption ON;

Impact on Radio Network Performance  If this parameter is set to OFF, the number of OFDM symbols occupied by the PDCCH is fixed and cannot be dynamically adjusted.  If this parameter is set to ON, the number of OFDM symbols occupied by the PDCCH is dynamically adjusted based on the number of required CCEs, and therefore cell downlink throughput increases. If this parameter is set to ECFIADAPTIONON, the dynamic adjustment of the number of OFDM symbols occupied by the PDCCH considers cell downlink throughput, and therefore can reach higher throughput when downlink frequency selective scheduling is enabled.

Activate PDCCH Capacity improvement Switch Object Parameter

MML Command

Impact on Radio Network Performance Setting this parameter to ON offers the following benefits:

 Activate PDCCH Capacity improvement switch

(1) PDCCH capacity is expanded, and therefore cell throughput increases; MOD CELLPDCCHALGO: LocalCellId=0, PdcchCapacityImproveSwitc h=ON;

(2) the uplink CCE allocation success rate increases, and therefore the access success rate increases and service drop rate decreases; (3) the CCE allocation success rate increases, and therefore cell throughput increases.

UL Interference Randomization Object Parameter

Set Adaptive Interference Randomizatio n

MML Command

Impact on Radio Network Performance

 If this parameter is set to FS_INRANDOM_ADAPTIVE, inter-cell interference decreases. Both throughput of cell edge users (CEUs) MOD CELLULSCHALGO: and the total cell throughput increase LocalCellId=x, when the cell is lightly loaded, and UlRbAllocationStrategy=FS_ throughput of CEUs increases but the INRANDOM_ADAPTIVE; total cell throughput may decrease  When the cell is heavily loaded. Setting this parameter to the default value FS_NONFS_ADAPTIVE has no impact on network performance

Activate DMRS Scheduling for Uplink timing Object Parameter

 Activate the mechanism of optimized demodulation reference signal (DMRS) scheduling for uplink timing

MML Command

MOD TATIMER: LocalCellId=0, TimingResOptSwitch= ON;

Impact on Radio Network Performance  If this parameter is set to OFF, more DMRS resources are consumed for uplink timing when sounding reference signal (SRS) resources are not configured for UEs in heavily loaded cells where there is a large number of UEs. As a result, the access success rate and uplink and downlink throughput decrease, and the service drop rate increases.  If this parameter is set to ON, DMRS resources used for uplink timing decrease. As a result, the access success rate and the uplink and downlink throughput do not decrease, and the service drop rate does not increase in heavily loaded cells where there is a large number of UEs. However, the uplink and downlink throughput of UEs that move faster than 120 km/h decreases because of delayed uplink timing.

Deactivate UL Pre-allocation Object Parameter

 Deactivate UL Pre-allocation

MML Command

MOD CELLALGOSWITCH: LocalCellId=0, UlSchSwitch=PreAlloc ationSwitch-0;

Impact on Radio Network Performance

if preallocation is enabled, the delay of uplink data transmisstion is shortened, but the uplink interference and UE power comsumption are increased.  if preallocation is disabled, the delay of uplink data transmission is increased, but the uplink interference and UE power consumption are decreased.

Deactivate UL Pre-allocation Object Parameter

 Deactivate UL Pre-allocation

MML Command

Impact on Radio Network Performance

MOD CELLALGOSWITCH: LocalCellId=0, UlSchSwitch=PreAlloc ationSwitch-0;

if preallocation is enabled, the delay of uplink data transmisstion is shortened, but the uplink interference and UE power comsumption are increased.  if preallocation is disabled, the delay of uplink data transmission is increased, but the uplink interference and UE power consumption are decreased.

Activate Special Signaling Retransmission Object Parameter

 Enable Special Signaling Retransmission

MML Command

Impact on Radio Network Performance  If this switch is on and the number of UEs in the cell is large, the number of retransmitted inter-RAT handover commands and the RRC Connection Release messages decreases, and less air interface resources are consumed.

MOD ENODEBALGOSWITCH: HighLoadNetOptSwitch =SPECSIGRETRANSOP If this switch is off, some UEs may not reply TSWITCH-1; to HARQs/ARQs of inter-RAT handover commands, which causes the eNodeB to retransmit inter-RAT handover commands repeatedly. In addition, some UEs may not send ACK to the eNodeB in response to the RRC Connection Release messages, which causes the eNodeB to retransmit the RRC Connection Release messages repeatedly. When one of the preceding conditions is met, uplink and downlink throughput in the cell may decrease.

Close DRX Object Parameter

 Close DRX or  Exclude UE Enter or Exit DRX according to traffic measurements

MML Command

MOD DRX: DrxAlgSwitch=OFF or FDD enter DRX Threshold=1000 FDD Exit DRX Threshold = 1000

Impact on Radio Network Performance

When this parameter is set to ON, UEs can enter DRX mode, and the power consumption of UEs decrease. The impact on the radio network performance depends on DRX parameter settings. When dynamic DRX is enabled, this parameter is invalid.  When both the FddEnterDrxThd parameter and the FddExitDrxThd parameter are set to 1000 and DRX is enabled, the eNodeB directly determines that the UE should enter or exit the DRX mode, but not according to the measurement result of UE traffic.

Activate SRI Measurement when DRX Close Object Parameter

MML Command

Impact on Radio Network Performance

 If this switch is on, not all SRIs fall into measurement gaps. Therefore, uplink  SR MOD signaling and data can be scheduled in a measurements ENODEBALGOSWITCH: timely manner, and the probability of service and conflict HoCommOptSwitch=Ba drops decreases. avoidance GAP sedSriGapOptSwitch-1;  If this switch is off, there is a possibility when DRX closed that all SRIs fall into measurement gaps. As a result, uplink signaling and data cannot be scheduled, and service drops occur.

Activate Adaptive RLC DRB Parameters Object Parameter

 Activate Adaptive RLC DRB Parameters

MML Command

Impact on Radio Network Performance

If this parameter is set to ON, the number of retransmissions and the number of times the status report is sent decrease. This can save air interface resources and reduce the MOD probability that an RRC connection RLCPDCPPARAGROUP: reestablishes because the number of RLC RlcPdcpParaGroupId=0, retransmissions has reaches the maximum RlcMode=RlcMode_AM, value. RlcParaAdaptSwitch=O If this parameter is set to OFF and the N; number of UEs in a cell increases, the number of invalid retransmissions and the number of times the status report is sent are excessive, increasing the probability of RRC connection reestablishment because the RLC retransmission has reached the maximum number of times.

Activate PUCCH IRC Object Parameter

MML Command

Impact on Radio Network Performance

 If this parameter is set to OFF, the number of false alarms increases may increase in scenarios of strong interference on the PRACH.

 Activate PUCCH IRC

MOD CELLALGOSWITCH:LOCA LCELLID=x,IRCSWITCH=  If this parameter is set to ON, the number PucchIrcSwitch-1; of false alarms in the PRACH decreases, random access success rate, handover success rate, resynchronization rate, and RRC reestablishment success rate increase. However, UEs in areas with weak coverage may attempt to access the network, which decreases the RRC setup success rate.

PDCP Packet Loss Timer infinity Object Parameter

MML Command

MOD  Set PDCP RLCPDCPPARAGROUP Packet Loss : Timer to RlcPdcpParaGroupId Infinity =5, DiscardTimer=Discar dTimer_Infinity;

Impact on Radio Network Performance

A large value of this parameter results in a long delay of services and a failure to meet the QCI requirement. A small value of this parameter leads to a severe case of PDCP data discarding and therefore low throughput. Reduce packet loss probability

PDCCH & PDSCH Downlink Scheduling Balance Object Parameter

MML Command

Impact on Radio Network Performance DataThdInPdcchPdschBal :  Setting this parameter to 0 has no impact on network performance.

DL Scheduling

MOD CELLDLSCHALGO: LocalCellId=0, DataThdInPdcchPdschBal = 17000, UeNumThdInPdcchPdsch Bal=100;

Setting this parameter to a non-zero value increases the physical resource block (PRB) usage in the PDSCH and downlink throughput in large traffic volume scenarios. A smaller value of this parameter results in a higher probability of a bearer being determined as a bearer with large packets. A larger value of this parameter results in a lower probability of a bearer being determined as a bearer with large packets.

Object Parameter

MML Command

Impact on Radio Network Performance

 UeNumThdInPdcchPdschBal :

DL Scheduling

MOD CELLDLSCHALGO: LocalCellId=0, DataThdInPdcchPdsch Bal= 17000, UeNumThdInPdcchPds chBal=100;

If the number of synchronized UEs in the cell is less than this parameter value, the network performance is not affected.  If the number of synchronized UEs in the cell is greater than or equal to this parameter value, PDCCH and PDSCH resources are balanced, increasing PRB usage in the PDSCH and downlink throughput in large traffic volume scenarios.

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