Wcdma Rns a en Load Balance 2 Ppt 201005 18
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Transcript of Wcdma Rns a en Load Balance 2 Ppt 201005 18
Load Balance
Content
Feature Description Function Introduction Load Evaluating Factors Load Balance in Initial RRC Procedure Load Balance in RAB Assignment Load Balance in Call Holding Procedure
Function Introduction
Why to Perform Load Balance Deploy the inter-cell traffic appropriately Enhance the system capacity and QoS
What Load to Balance Uplink interference (RTWP) Downlink power (TCP) Downlink code resources
When to Perform Load Balance Initial RRC procedure RAB assignment procedure Call holding procedure
Where to Perform Load Balance Intra-system or Inter-RAT neighboring cell configured (ShareCover,
GsmShareCover)
Content
Feature Description Function Introduction Load Evaluating Factors Load Balance in Initial RRC Procedure Load Balance in RAB Assignment Load Balance in Call Holding Procedure
Load Evaluating Factors
Three evaluating factors: uplink interference, downlink power, and downlink code resources Switches: UlLdBalPwrSwch, DlLdBalPwrSwch, and
LdBalCdSwch Weight: DlLdBalPwrWeight, UlLdBalPwrWeight, and
LdBalCdWeight Threshold: DlLoadNeedBal2U, UlLoadNeedBal2U, and
DlCdLdNeedBal2U Difference: ExtraCDeltaTrd, ExtraCDeltaTru, and
ExtraCDeltaCdTrd
Uplink interference
Uplink payload = Load generated by uplink DCH +
Load generated by non-scheduling E-DCH
+
Load generated by the throughput of GBR services of scheduling E-DCH
Downlink power
0
NOHSDSCHPower HSDSCHRequiredPowerSnum
ii
downl i nk payl oad
Code resource
Code Usage=number of Non HS-PDSCH occupied
SF128+MinHspdschNum*128/16
Where,
MinHspdschNum = Max(MinHspdschNum in OMCR, MinHspdschNumbyGBR)
Coupling Operation of These Factors
k : the number of factors opened for load Balance Loadi : source cell-actual load subtracts Delta
target cells- the actual load ThrdLoadi : load Balance threshold Weighti : the weight of each factor The sum of weight of each factor is 1. If all three
factors are switched “OFF”, load Balance is not performed.
k
1iiii Weight*ThrdLoadLoadLoadWeight )(
Content
Feature Description Function Introduction Load Evaluating Factors Load Balance in Initial RRC Procedure Load Balance in RAB Assignment Load Balance in Call Holding Procedure
Load Balance in Initial RRC Procedure
In case of: InitRrcLBSw switch is set to ON Serving cell reaches the threshold Neighbor cells with “Overlap” or “ Covers” Load balance, select cell with the lowest load to access
The neighbor cell must be same frequency band with original cell.
Load Balance in Initial RRC Procedure
F1 (HSPA)PS prefer
F2 (R99+HSPA)CS+PS prefer
UE camping
F1 (HSPA)PS prefer
F2 (R99+HSPA)CS+PS prefer
Content
Feature Description Function Introduction Load Evaluating Factors Load Balance in Initial RRC Procedure Load Balance in RAB Assignment Load Balance in Call Holding Procedure
Load Balance in RAB Assignment
In case of: RabAssLBSw switch is set to ON (for CS service,
CsBalSwch should be also considered) Serving cell reaches the threshold Neighbor cells with “Overlap” or “ Covers”
Load balance, select cell with the lowest load to access
Service properties and UE capabilities should be considered in selecting the target cell.
Load Balance in RAB Assignment
F1 (R99+HSPA)CS+PS prefer
F2 (R99)CS prefer
UE registers Voice call
F1 (R99+HSPA)CS+PS prefer
F2 (R99)CS prefer
HS call
Content
Feature Description Function Introduction Load Evaluating Factors Load Balance in Initial RRC Procedure Load Balance in RAB Assignment Load Balance in Call Holding Procedure
Load Balance in Call Holding Procedure
In case of CallHoldLBSw being set to ON, when: Handover, relocation from other system Handover, relocation from other RNC Call re-establishment triggered by CELL UPDATE State transition from non-CELL_DCH to CELL_DCH
Load balance, select cell with lowest load to access