3g optimization cycle - central improvements.pptx

14
HUAWEI TECHNOLOGIES CO., LTD. CS/PS 3G Improvement Project

Upload: muhammad-bilal-junaid

Post on 18-Jul-2016

75 views

Category:

Documents


16 download

TRANSCRIPT

Page 1: 3G Optimization Cycle - Central Improvements.pptx

HUAWEI TECHNOLOGIES CO., LTD.

CS/PS 3G Improvement Project

Page 2: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 2

Summary• Central 3G PS traffic increased by 300% recently as a result of new rollout, promotions and 40W power

upgrade

• This resulted in degradation is PS retention KPIs as well as increased interference resulting into voice call drops as well

• Along with PMCL planning, a road map was agreed to optimize the CS/PS signaling procedures as well as triggering thresholds to counter the increased interference and improve the CS/PS retention without compromising on user experience

• Key actions are listed below

MultiRAB optimization (R99 RAB instead of HS RAB during voice call) Coverage based HSUPA fallback (based on UE Tx power) SRB (signaling) over DCH instead of HS to reduce SRB drops PS IRAT HO threshold to trigger timely PS HO to reduce R99 drops 2G to 3G Reselection changes to capture more 3G users

Page 3: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 3

KPI Score Card

Page 4: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 4

Central-DCR Voice

MultiRAB optimization improved the voice DCR by 25%

Page 5: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 5

Central-DCR HSPA

Coverage based HSUPA fall back (based on UE Tx power) and SRB over DCH improved the HSPA DCR by 50%

Page 6: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 6

Central-DCR R99

MultiRAB optimization and PS IRAT fine-tuning improved the R99 DCR by 44%

Page 7: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 7

IRAT PS Success Rate

PS IRAT parameter tuning and Reselection parameter changes improved PS IRAT HO from 90% to 92%

Page 8: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 8

Central-Traffic

Central trend shows consistent increase in CS/PS traffic while throughput is also consistent despite of optimization activities that improved the CS/PS DCR without compromise on user throughput and traffic

Page 9: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 9

ConclusionParameter and feature fine tuning has resulted in 25-50% reduction in CS/PS DCR even with growing traffic and consistent throughput

Page 10: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 10

CSPSMulti-RAB Session with PS

on HSDPA & CS on DCHMulti-RAB Session with CS & PS on DCH

P S

High no. of reconfigurationsLow no. of reconfigurations

Higher Throughput in HS but more drops

CSPre Post

Lower Throughput in DCH but less drops

Multi-RAB switch to DCH

CS call drops in CS/PS combined services are mainly caused by serving cell changes. That is because the physical channel reallocation and Radio Bearer (RB) reallocation triggered by serving cell change take a long period of time. If signal strength changes during this period, CS calls may drop because soft handovers are not performed in time.The corresponding algorithm is optimized to ensure that PS services in CS/PS combined services are carried on the DCH and the PS services cannot perform Dynamic Channel Configuration Control (DCCC). This reduces the possibility of physical channel reallocation and RB reallocation.

Page 11: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 11

Signaling Radio Bearer (SRB) carries Signaling data. An SRB is used during connection establishment to establish the Radio Access Bearers (RABs) and then also to deliver signaling while on the connection (for example, to perform a handover, reconfiguration or release). For higher RABs like HSUPA/HSDPA faster signaling is required to improve throughput so SRB can be carried on HS-SCCH channel. HS-SCCH does not have power control etc, this makes it vulnerable to drops, hence with SRB over HSPA although we achieve better throughput our drop rate is higher.

Mapping of SRB to physical channel changed from HS-SCCH to DCH

SRB

SRB over DCH

Page 12: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 12

H2D based on Coverage

Feature DescriptionWhen this feature is turned on, the RNC determines whether the uplink coverage of a UE is insufficient during data connection. This includes both new & existing data connections. The decision is based on the Ec/No reported by the UE. In this case, the RNC establishes or moves the Data service on R99 channels instead of on HSUPA channels. The Ec/No decision threshold specifies whether to services should be switched over from E-DCHs to DCHs. This prevents call drops when HSUPA signals are weaker than R99 signals.

Parameter ChangesSET UCORRMALGOSWITCH: ReservedSwitch0=RESERVED_SWITCH_0_BIT5-1&RESERVED_SWITCH_0_BIT7-1, ReservedU32Para0=25;

Currently ReservedU32para0=0 which means effectively this switch is not working and that is why this feature did not give any improvement in DCR

Page 13: 3G Optimization Cycle - Central Improvements.pptx

HISILICON SEMICONDUCTORHUAWEI TECHNOLOGIES CO., LTD. Page 13

UE TxPower Change

Different rate has different coverage. When UE moves around in a cell, the link quality varies and the UE Txpower has to be increased to ensure better rate. The threshold of UE transmit power is slighlty changed, so that the value in which rate increase should be stopped is reached sooner, this effectively reduces the maximum power allowed for the UE. As the maximum power allowed for UE is reduced the overall noise floor is reduced which improves RTWP and hence HSPA DCR is improved. The drawback is that at cell edge the UE may not get the best throughput

Page 14: 3G Optimization Cycle - Central Improvements.pptx

Thank youwww.huawei.com