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3G Radio Resource Description

together we can makeit convergence Radio Resources

In 3G there are 4 main resources

1)Code

2)Power

3)NodeB

4)Iub

Resources and configuration

•In Huawei WCDMA network, to avoid the congestion and blockage of the service, we have to monitor the following resources :

NE Type Resource ExpansibleNodeB Level -CE card and license

-NodeB code license-UL and DL Iub bandwidth

YesYesYes

Cell Level -OVSF code-UL power -DL power

NoYesYes

RAN Resource diagram

BBU

RRU1

RNCRRU2

RRU3

•DL total power/DL ENU•RTWP/UL ENU•OVSF Code (DCH/HS-PDSCH)

•DL total power/DL ENU•RTWP/UL ENU•OVSF Code (DCH/HS-PDSCH)

•DL total power/DL ENU•RTWP/UL ENU•OVSF Code (DCH/HS-PDSCH)

-CE card-CE license-HS-PDSCH code license

UL/DL Iub bandwidth

Traffic and KPI statistic

•To associate the actual situation of resource usage we have to consider in term of :

- CS and PS traffic- Congestion- Utilization

Service distribution

•Each service type will occupy different resources. Hence we should divide the traffic volume corresponding to each service type to understand the characteristic of the cell.

– AMR– VP– PS R99 DL– PS R99 UL– HSDPA– HSUPA

CE Resource Description

•CE resource is consisting of hardware and software. CE is the pool resource at NodeB level, all cells connected to NodeB will share the same CE resource.

– Hardware• Number of CEs will be vary upon the model of card.• The monitoring will be done at NodeB level.

– Software• 1 License will be equal to 16 CEs.• Number of UL/DL license can be assigned independently.• The monitor can be done separately for UL and DL.

OVSF Code Resource Description

OVSF Code is the limit resource of each cell. The expansion can’t be possible in a single cell.

•Typical usage of OVSF code– AMR : SF128– VP : SF64– PS R99 DL : SF8 – SF128– HSDPA : SF16

NodeB HSDPA Code License Description

•Except the available number of free OVSF code, HSDPA license is required.

– HSDPA code license is a pool resource at BBU as same as CE.– Insufficient code license can degrade the throughput of HSDPA

user as well.

UL Power Resource Description

•Even the UL power is not limit corresponding to each UE power, but the noise raise will trig the rejection due to Call Admission Control as well. Hence, the increment in UL load can cause service rejection and slow down the data service.

DL Power Resource Description

•DL Power Limit is considered at RRU total power.

•In general, the common control channel will consume about 20% of total power.

•The power consumption of each service will be different as well as the radio condition of each UE (e.g. distance, RSCP, Ec/Io)

•HSDPA will use the remaining power left from R99 service.

Total resource usage module

-Power-OVSF code-CE

-Desire QoS-Congestion

-CS user-PS R99 User-HSDPA User-HSUPA User

Service distribution

Resources User experience

Rejection

2 states of service interruption• The user can’t get the service (rejection).• The user can’t get at the desire QoS (low throughput of data service)

Total RRU power setting•Total Carrier Power (TCP) is one of limited resource depending upon

RRU total power output that impact directly to cell capacity and performance. Although it’s the same RRU power, it may different in the capacity because of UE distribution in a cell. To overview the power setting in a cell, we can check parameter setting of total power and CPICH power.

•CPICH Power– MaxPCPICHPower (~ 10% of total cell power)– Default = 33 or 36 dBm

•Total Power– MaxTxPower– Default = 43 or 46 dBm according to license

By the way, CPICH power + common channel will consume around 20% of total cell power.

TCP Counter and monitoring•Example : BKD0040U3

– MaxTxPower = 43 dBm– MaxPCPICHPower = 33 dBm

•We can monitor TCP usage from counter

– VS.MaxTCP (R99+HSDPA)– VS.MeanTCP (R99+HSDPA)– VS.MaxTCP.NonHS (R99)– VS.MeanTCP.NonHS (R99)

30

32

34

36

38

40

42

44

dBm

Average of VS.MaxTCP Average of VS.MeanTCP

30

32

34

36

38

40

42

44

dBm

Average of VS.MaxTCP.NonHS Average of VS.MeanTCP.NonHS

MaxTxPower

PCPICH

MaxTxPower

PCPICH

PCPICH + Common channel

PCPICH + Common channel

OVSF and CE Consumption for DL DCH service

Rate (kbps) SF CE Consumption3.4 256 1

13.6 128 18 128 1

16 128 132 64 164 32 2

128 16 4144 16 4256 8 8384 8 8

OVSF and CE Consumption for UL DCH service

Rate (kbps) SF CE Consumption3.4 256 1

13.6 64 18 64 1

16 64 132 32 1.564 16 3

128 8 5144 8 5256 4 10384 4 10

Counter of RRC rejection due to lack of resource

•RRC Connection Setup Rejection due to lack of resource

Counter of CS RAB rejection due to lack of resource

•Number of CS RAB Unsuccessfully Established due to Radio Resource Congestion (Cell)

•Number of CS RAB Unsuccessfully Established due to Iub Bandwidth Congestion (Cell)

Counter of PS RAB rejection due to lack of resource

•Number of PS RABs Unsuccessfully Established due to Radio Resource Congestion (Cell)

•Number of RABs Failing to Be Set Up in PS Domain due to Iub Bandwidth Congestion (Cell)

Counter of PS RAB rejection due to lack of resource for different service

•Number of Unsuccessful PS RAB Setups for Different Services due to Congestion (Cell)

Observe the type of service

•Except the resource usage and rejection, to realize the resource consumption of the cell, we have to figure out the load of each service of a cell to see the distribution and judge which one consumes load the most.

•The service of a single user may be single-RAB or Multi-RAB

•The service of a single user will consume balance or unbalance load between UL and DL e.g.

– AMR user : UL CS AMR and DL CS AMR– Old Model mobile : DL+UL PS R99– iPhone and BB user : UL PS R99 and DL HSDPA– Datacard user : UL HSUPA and DL HSDPA (all the equipment support

HSUPA will support HSDPA).

User number counter in a cell

•We can roughly discover the number of users to imply the traffic density in a cell.

VS.HSDPA.UE.Mean.Cell

VS.HSUPA.UE.Mean.Cell

VS.CellDCHUEs

VS.CellFACHUEs

Average no of HSDPA users

Average no of HSUPA users

Average no of users in CELL_DCH state

Average no of users in CELL_FACH state

AMR user number counter in a cell

•To sum up the number of AMR user we can calculate from

Number of AMR users =

•UL/DL CE consumption for a AMR User = 1/1

VS.AMR.Ctrl.DL4.75+VS.AMR.Ctrl.DL5.15+VS.AMR.Ctrl.DL5.9+VS.AMR.Ctrl.DL6.7+VS.AMR.Ctrl.DL7.4+VS.AMR.Ctrl.DL7.95+VS.AMR.Ctrl.DL10.2+VS.AMR.Ctrl.DL12.2

HSDPA+HSUPA user number counter in a cell

•Assume that HSUPA user is HSDPA user as well. Hence while UL is HSUPA, DL will be HSDPA.

Number of HSDPA+HSUPA Users =

•UL CE consumes up to bit rate of HSUPA

VS.HSUPA.UE.Mean.Cell

HSDPA+R99 user number counter in a cell

•Typical mobile in a market will support only HSDPA while using R99 in UL. Therefore,

Number of HSDPA+R99 User =

•A HSDPA User consume 1*SF256 (1 CE) in DL for A-DCH

•UL CE consumes up to bit rate of DCH

VS.HSDPA.UE.Mean - VS.HSUPA.UE.Mean.Cell

DL+UL PS R99 user number counter in a cell

•Assume that if the UE model supports only DL R99, the number of DL+UL R99 is equal to number of DL R99 User

Number of DL+UL R99 User =

•DL CE consumes up to bit rate of DL DCH

•UL CE consumes up to bit rate of UL DCH

VS.RB.DLConvPS.8+VS.RB.DLConvPS.16+VS.RB.DLConvPS.32+VS.RB.DLConvPS.64+VS.RB.DLStrPS.8+VS.RB.DLStrPS.16+VS.RB.DLStrPS.32+VS.RB.DLStrPS.64+VS.RB.DLStrPS.128+VS.RB.DLStrPS.144+VS.RB.DLStrPS.256+VS.RB.DLInterPS.8+VS.RB.DLInterPS.16+VS.RB.DLInterPS.32+VS.RB.DLInterPS.64+VS.RB.DLInterPS.128+VS.RB.DLInterPS.144+VS.RB.DLInterPS.256+VS.RB.DLInterPS.384+VS.RB.DLBkgPS.8VS.RB.DLBkgPS.16+VS.RB.DLBkgPS.32+VS.RB.DLBkgPS.64+VS.RB.DLBkgPS.128+VS.RB.DLBkgPS.144+VS.RB.DLBkgPS.256+VS.RB.DLBkgPS.384

Resource Threshold : DL OVSF Code

•For RRC connection setup request, the admission accepted when code resource is sufficient for RRC Connection.

•For handover, the admission accepted when code resource is sufficient for the service.

•For other R99 service, the admission accepted when code resource after admit the service is less than HandOver Credit and Code Reserved SF.

•Dl HandOver Credit and Code Reserved SF = SF32

Resource Threshold : CE (UL/DL)

•For RRC connection setup request, the admission accepted when CE resource is sufficient for RRC Connection.

•For handover, the admission accepted when CE resource is sufficient for the service.

•For other service, the admission accepted when CE resource after admit the service is not less than Ul HandOver Credit Reserved SF/Dl HandOver Credit and Code Reserved SF.

•Ul HandOver Credit Reserved SF = SF16 (3 CE)•Dl HandOver Credit and Code Reserved SF = SF32 (2 CE)

Iub

Code

Power

CE

Capacity upgrade solutionIn resource expansion, these activities would be performed to increase or

balance cell capacity (This is assumed that the site has been well optimization)

1.WBBP upgrade/downgrade

2.UL/DL CE upgrade/downgrade

3.Increase UL ENU (if RTWP is normal)

4.Increase total RRU power

5.Reduce CPICH power

6.Reduce fix HS-PDSCH code, if code congest from Voice

7.Increase fix HS-PDSCH code, if low throughput on HSPDA

8.Increase Iub bandwidth

Note : Capacity upgrade in term of optimization would be taken into account better in cell level. The optimizer should control coverage and parameter e.g. handover in order to balance between coverage and capacity of itself and surrounding cells.

WBBP and CE License up/down grade

•Resource unit

– WBBP : 128 UL/DL– CE License : 16 CE in UL or DL separately

•CE resource configuration

– To configure and use CE resource at NodeB, it will be defined as BB Resource Group separately for UL and DL

– The main concern about the BB Resource Group is • If configure multi WBBP card into one UL BB Resource Group, CE is sum of

CE from every WBBP cards.• If configure multi WBBP card into one DL BB Resource Group, CE is

CE of only one WBBP card.

128 UL/DL

128 UL/DL

One DL BB Resource and UL BB Resource Group

UL CE = 256DL CE = 384

•Recommendation in CE up/down grade– Add/remove CE License on demand. The CE License is in 16 CE unit. Add or remove in

term of 1 license (smallest unit) is recommended for highest efficiency.– WBBP card should be utilized at full license prior to add WBBP.– If UL CE is congestion at full license, adding new WBBP card is needed.– If DL CE is congestion. Reconfigure congested sector to separated WBBP Card can solve

the problem prior to add new WBBP

WBBP and CE License up/down grade

128 UL/DL

128 UL/DL UL CE = 256

Sector1

Sector2

Sector3

128 UL/DL

128 UL/DL

DL BB Resource Group 0DL BB Resource Group 1UL BB Resource Group 0

DL CE = 128Sector1

Sector2

Sector3

DL CE = 128

UL CE = 256

DL CE = 128

DL BB Resource Group 0UL BB Resource Group 0

Power congestion solution•As we have analyzed the root cause of power congestion whether UL (ENU) or DL

(RRU power). The solution would be different up to the type of power congestion.

•Only limit power resource on UL is ENU, UL ENU can adjust ranging from 1 – 200

– The concern of increasing UL ENU is RTWP. Although, call admission is success but it may lead to voice quality and drop call problem to itself or other UEs.

– The performance after increasing UL ENU should be closely monitored.

•If power is congested due to DL power

– If coverage is not the issue of the cell, we can slightly reduce the CPICH power. 1 dB step adjust is recommended.

– If coverage is the main concern in the serving area, we can increase 1 dB step adjust is recommended.

DL OVSF Code Congestion Solution

•At the moment, code congestion would be caused by insufficient code for AMR and PS R99. However, PS DL R99 should be very low as most of DL PS RB is HSDPA. Thus, most of the service congestion due to code should be AMR.

•To overcome this problem, the reduction of fix HS-PDSCH code would be the best solution at the moment. The trade-off between AMR and HS-PDSCH code allocation is unavoidable according to limit of DL OVSF Code.

•1 SF16 of HS-PDSCH can convert to about 8 AMR (SF128). This would be equivalent to 1 TRX. Thus, the fix HS-PDSCH 1 code reduction step would recommend to avoid as much as possible impact to HSDPA throughput.

1 HS-PDSCH(SF16)

AMR (SF128)

AMR (SF128)

AMR (SF128)

AMR (SF128)

AMR (SF128)

AMR (SF128)

AMR (SF128)

AMR (SF128)

12

3

4

5

6

78