Dynamic Radio Bearer Control Feature Implementation Procedure and Algorithm

Content

Introduction

Related Measurement

R99 DRBC Algorithm

HSDPA DRBC Algorithm

HSUPA DRBC Algorithm

What is DRBC?

Dynamic Radio Bearer Control (DRBC) is used to allocate resource efficiently to make full use of it in system running state, according to subscriber requirement and system resource utilization.

How DRBC works?

Parameter DRBC Switch(DrbcSwch) is used to start or stop service dynamic rate and channel switching algorithm. If DrbcSwch is ON, the function works, including initial

channel allocation, rate and channel switching and so on.

If DrbcSwch is OFF, after initial rate and channel for service is allocated, it will never happen switching before service release.

Initial Channel Allocation

Initial channel allocation is related to cell and UE capability, service type and rate.

Rate and Channel Switching

Connected Mode

Idle Mode

CELL_DCH

CELL_FACH

URA_PCH

PCH

DL FACH/ UL RACH

DL HS-DSCH/ UL DCH <-> DL DCH/UL DCH

DL HS-DSCH/ UL E-DCH <-> DL DCH/ UL DCH

DL DCH/ UL DCH -> DL DCH/UL DCH（UL/DL Decrease or Increase Rate）

Content

Introduction

Related Measurement

R99 DRBC Algorithm

HSDPA DRBC Algorithm

HSUPA DRBC Algorithm

Channel Switching

Content

Introduction

Related Measurement

R99 DRBC Algorithm

HSDPA DRBC Algorithm

HSUPA DRBC Algorithm

Initial Channel Allocation - Signaling

The rate and transport channel for signaling of RRC connection can be set through parameter “InitRrcOnDch”: Forced to DCH and Using Normal Speed Signaling Forced to DCH and Using High Speed Signaling (default) Forced to FACH Not Forced, Using Normal Speed Signaling on Cell-DCH

State Not Forced, Using High Speed Signaling on Cell-DCH State

Initial Channel Allocation - Service

FACHFACHDCHDCH

ConversationConversation StreamingStreaming Interactive &Interactive & BackgroundBackground

DL MaxBR >= DL MaxBR >= Rfach Rfach or or

UL MaxBR >= UL MaxBR >= RrachRrach

Y N

Initial Rate Calculation If the DRBC switch DrbcSwch is set to OFF,

the DCH initial rate = min(max (highest rate level of DBRC, GBR), MaxBR).

If the DRBC switch DrbcSwch is ON,

the DCH initial rate = min (max (min (lowest rate level of DBRC, DCH rate limitation), GBR), MaxBR).

The uplink and downlink DRBC rate levels are configured by UlRateAdjLev[MAX_NUM_RATE_ADJUST] DlRateAdjLev[MAX_NUM_RATE_ADJUST].

The DCH rate limitation:

NRT servive of uplink DCH rate limitation is NrtMaxUlRateDch, downlink DCH rate limitation is NrtMaxDlRateDch;

RT service of uplink DCH rate limitation is RtMaxUlRateDch, downlink DCH rate limitation is RtMaxDlRateDch.

Initial Channel Allocation - Concurrent Service

DCHDCHDCHDCH

FACHFACH

New service Requires DCHNew service Requires DCH

New service Requires FACHNew service Requires FACH

FACHFACH

FACHFACH

New serviceNew service

Current serviceCurrent service

Initial Channel Allocation - Concurrent ServiceNew service established

Current service in Cell-DCH state

New service establish on

Cell-DCH stateCell-FACH→ Cell-DCH Cell-FACH state

Finish

New service type?

New service requires to establish on

Cell-DCH

New service requires to establish on

Cell-FACHY

N

Concurrent Service Rate Calculation The calculation is similar as only single service.

For concurrent CS and PS(S/I/B) services, If DrbcSwch is OFF, the DCH rate is:

min(max (highest rate level of DRBC, GBR), MaxBR)

If DrbcSwch is ON, the DCH rate is:

min( max( min(lowest rate level of DRBC, DCH rate limitiation), GBR), MaxBR)

R99 Channel Switching

CELL-DCH

DCH/DCH

CELL-FACH

FACH/RACH

URA_PCH

PCHIdle

Reconfigure SF1. UL/DL Traffic Volume Based2. DL D-TCP Based3. UL TxP Based4. Cell’s RTWP5. Cell’s TCP

UL DCH/DL DCH -> UL RACH/DL FACH1. UL&DL Traffic Volume Based2. Support Cell_FACH

UL RACH/DL FACH -> UL DCH/DL DCH1. UL/DL Traffic Volume Based2. Cell’s RTWP & Cell’s TCP

UL DCH/DL DCH -> PCH1. UL&DL Traffic Volume Based2. Support PCH switching

UL RACH/DL FACH -> IDLEUL&DL Traffic Volume Based

UL DCH/DL DCH ->IDLEUL&DL Traffic Volume Based

PCH->IDLEDL&UL Traffic Volume Based

UL RACH/DL FACH -> PCH1. UL&DL Traffic Volume Based2. Support PCH switching

PCH -> UL RACH/DL FACHUL/DL Traffic Volume based

Traffic Related Events Event 4A

triggered when measured traffic value exceeds an absolute threshold which is related to DCH increasing rate

Event 4B triggered when measured traffic value is smaller than

an absolute threshold which is related to DCH decreasing rate

Event 4B0 triggered when measured traffic value is 0. 4B0 event

is an special case of 4B.

Time to Trigger and Pending Time

Traffic Volume

4A Threshold

Time to Trigger

PendingTime

PendingTimeTime to

TriggerTime to Trigger

Report 4A Report 4A Report 4A Time

Time to Trigger and Pending Time are used to prevent triggering too frequently.Pending Time is a time for shielding in the same event reporting.

UL TxP Related Events Event 6A1, 6B1

used for UL decreasing rate when 6A1 is reported, UE is considered as a high

transmitted power status, and the uplink rate can be decreased.

when 6B1 is reported, UE is not in a high transmitted power status, and UL decreasing rate will be stopped.

Event 6A2, 6B2 used to check whether UE TxP is in a low level when 6B2 is reported, UE is considered as a low

transmitted power status, and the UL rate can be increased.

when 6A2 is reported, UE is not in a low transmitted power status, and UL increasing rate will stopped.

UL TxP Related Events

UE TxP

Time

Thr_6A1

Thr_6A2

Thr_6B1

Thr_6B2

Reporting Event 6A1

Reporting Event 6B1

Reporting Event 6A2

Reporting Event 6B2

In this example, Time To Trigger=0

DL D-TCP Related Events DL D-TCP stands for downlink Transmitted Carrier

Power for dedicated channel of single UE, which is measured by NodeB. It acts as one of the factors to trigger decreasing rate. Meanwhile, it is also a restriction for increasing rate.

Event A and B If the DL D-TCP measurement value is larger than a

upper threshold, event A will be triggered. Rate will be decreased, the DL D-TCP for the UE is considered as a high transmitted power status.

Otherwise the DL D-TCP for the UE is considered as a low transmitted power status.

DL D-TCP Related Events

upper_threshold

lower_threshold

DL D-TCP

Time

Event B

In this example, Time To Trigger=0

Event A Event B

Content

Introduction

Related Measurement

R99 DRBC Algorithm

HSDPA DRBC Algorithm

HSUPA DRBC Algorithm

HSDPA Initial Channel Allocation - Signaling The rate and transport channel for signaling of RRC

connection is the same as the R99. For the setup of RAB, the signaling channel is

selected by the following principles: The low-speed bearer signaling DL DCH/UL DCH is

selected if there is DL DCH/UL DCH bearer service. All services are on the DL HS-DSCH/UL DCH. If both

UTRAN and UE support F-DPCH, the signaling is on the DL HS-DSCH/UL DCH. Otherwise, the signaling is mapped to DCH/DCH low rate signaling.

Initial Channel Allocation - Service

FACHFACH

DCHDCH HS-DSCHHS-DSCH

ConversationalConversational streamingstreaming I/BI/B

12

31

2

Initial Channel Allocation - Concurrent Service

DCHDCH

HS-DSCHHS-DSCH

FACHFACH

I/B+I/B

All services use same channel typeAll services use same channel type

I/B+S or S+SI/B+S or S+S

All services use same channel typeAll services use same channel type

Initial Channel Allocation - Concurrent Service

DCHDCH

HS-DSCHHS-DSCH

C+I/BC+I/BDifferent services go to different channelDifferent services go to different channel

I/B+C or S+C or I/B+S+CI/B+C or S+C or I/B+S+C

Different services go to different channelDifferent services go to different channel

CC

S/I/BS/I/B

CC

I/BI/B

HSDPA Channel Switching

CELL_DCH

HS-DSCH/DCHDCH/DCH

CELL_FACH

RACH/FACH

URA_PCH

PCHIdle

Reconfig SF1. UL/DL Traffic Volume Based2. DL D-TCP Based3. UL TxP Based4. Cell’ s RTWP5. Cell’ s TCP

Transition of DCH/DCH -> FACH/RACH1. UL&DL Traffic Volume Based

2. Support CELL_FACH

Transition of HS-DSCH/DCH -> FACH/RACH1. UL&DL Traffic Volume Based

2. Support CELL_FACH

Transition of FACH/RACH -> DCH/DCH1. UL/DL Traffic Volume Based2. Cell’ s RTWP & Cell’ s TCP

Transition of FACH/RACH -> HS-DSCH/DCH1. UL/DL Traffic Volume Based

2. UE &Cell Capability3. Cell’ s RTWP & Cell’ s TCP

Transition of DCH/DCH -> PCH1. UL&DL Traffic Volume Based2. Support PCH

Transition of HS-DSCH/DCH -> PCH1. UL&DL Traffic Volume Based2. Support PCH

Transition DL DCH -> DL HS-DSCH1. DL Traffic Volume Based2. Channel Quality Measure Based (Option)3. UE &Cell Capability

Transition DL HS-DSCH -> DL DCH1. Channel Quality Measure Based (Option)

Transition of FACH/RACH -> IDLE1. UL&DL Traffic volume Based

Transition of DCH/DCH -> IDLE1. UL&DL Traffic Volume Based

Transition of HS-DSCH/DCH -> IDLE1. UL&DL Traffic Volume Based

Transition of PCH->IDLE1. DL&UL Traffic Volume Based

Transition of FACH/RACH -> PCH1. UL&DL Traffic Volume Based2. Support PCH

Transition of PCH -> FACH/RACH1. UL/DL Traffic Volume Based

Measurement and Events Based on downlink channel quality

1F event: DL HS-DSCH -> DL DCH 1E event & traffic volume E4A: DCH-> HS-DSCH

Mobility-based channel switching the source cell supports HSDPA, but the target cell

only supports R99

Measurement and Events HSDPA support ：

CELL_DCH(DL HS-DSCH/UL DCH)<->CELL_FACH switching triggered by traffic (dual directions)

CELL_DCH (DL HS-DSCH)<->DL DCH Triggered by traffic DCH->HS-DSCH Triggered by pilot channel quality HS-DSCH->DCH Switching triggered by mobility (dual directions)

CELL_DCH (DL HS-DSCH/UL DCH)<->URA_PCH CELL_DCH (DL HS-DSCH/UL DCH)->IDLE

Pilot Channel Quality Measurement The channel quality measurement is for the switching from

HS-DSCH to DCH. The Event 1E and Event 1F are used. The channel quality measurement CQ is performed on

P-CPICH. If the UE supports HS-DSCH, or ,UE are using DCH and the best cell in active set support HS-DSCH, the measurement is initiated.

Spectrum efficiency

CQ

DCH

HS-DSCH

1F threshold 1E threshold

Pilot Channel Quality Measurement 1E event ： when the pilot signaling quality is larger than an

absolute threshold (ThreshUsedFreq) and this condition lasts for a moment (TrigTime), event 1E will be reported.

1F event ： when the pilot signaling quality is lower than an absolute threshold (ThreshUsedFreq) and this condition lasts for a moment (TrigTime), event 1F will be reported.

1E event

Absolute threshold

Reporting event 1E

Measurement quantity

Time

P CPICH 1

P CPICH 2

P CPICH 3

1F event

Absolute threshold

Reporting event 1F

Measurement quantity

Time

P CPICH 1

P CPICH 2

P CPICH 3

Content

Introduction

Related Measurement

R99 DRBC Algorithm

HSDPA DRBC Algorithm

HSUPA DRBC Algorithm

Initial Channel Allocation - Signaling The signaling channel allocation process upon the RRC

connection setup is the same as the R99 policy. For the setup of RAB allocation service, the signaling channel

switching complies with the following principles: The low-speed bearer signaling DL DCH/UL DCH is

selected if there is DL DCH/UL DCH bearer service. If all the services are on the DL HS-DSCH/UL DCH: If both

the system and UE support F-DPCH, the signaling is on the DL HS-DSCH/UL DCH; otherwise, the signaling is mapped to DCH/DCH low rate signaling.

If all the services are on the DL HS-DSCH/UL E-DCH: If both the system and UE support F-DPCH, the signaling is on the DL HS-DSCH/UL E-DCH; otherwise, the signaling is mapped to DCH/DCH low rate signaling.

Initial Channel Allocation - Service

FACHFACH

DL DCH/UL DCHDL DCH/UL DCH DL HS-DSCH/DL HS-DSCH/

UL E-DCHUL E-DCH

conversationalconversational streamingstreaming I/BI/B

12

4

1

2

DL HS-DSCH/DL HS-DSCH/

UL DCHUL DCH

3

3

Initial Channel Allocation - Concurrent Service

DCHDCH

FACHFACH

I/B+I/BI/B+I/BAll services use same channel typeAll services use same channel type

I/B+S I/B+S

OR OR

S+SS+S

All services use same channel typeAll services use same channel type

DL HS-DSCH/DL HS-DSCH/

UL E-DCHUL E-DCH

DL HS-DSCH/DL HS-DSCH/

UL DCHUL DCH

Initial Channel Allocation - Concurrent Service

DCHDCH

C+I/BC+I/B

Different services go to different channelDifferent services go to different channel

I/B+CS or S+CS or

I/B+S+CS

Different services go to different channelDifferent services go to different channel

CC

I/B/SI/B/S

I/BI/B

CC

DL HS-DSCH/DL HS-DSCH/

UL E-DCHUL E-DCH

DL HS-DSCH/DL HS-DSCH/

UL DCHUL DCH

HSUPA Channel Switching

CELL_DCH

DCH/DCHCELL_FACH

RACH/FACH

URA_PCH

PCHIdle

Reconfig SF1. UL/DL Traffic Volume Based2. DL D-TCP Based3. UL TxP Based4. Cell’ s RTWP5. Cell’ s TCP

Transition of DCH/DCH -> FACH/RACH1. UL&DL Traffic Volume Based2. Support CELL_FACH

Transition of HS-DSCH/DCH -> FACH/RACH1. UL&DL Traffic Volume Based2. Support CELL_FACH

Transition of HS-DSCH/E-DCH -> FACH/RACH1. UL&DL Traffic Volume Based2. Support CELL_FACH

Transition of FACH/RACH -> DCH/DCH1. UL/DL Traffic Volume Based2. Cell’ s RTWP & Cell’ s TCP

Transition of FACH/RACH -> HS-DSCH/DCH1. UL/DL Traffic Volume Based2. UE &Cell capability3. Cell’ s RTWP & Cell’ s TCP

Transition of FACH/RACH -> HS-DSCH/E-DCH1. UL/DL Traffic Volume Based2. UE &Cell capability3. Cell’ s RTWP & Cell’ s TCP

Transition of DCH/DCH -> PCH1. UL&DL Traffic Volume based2. Support PCH

Transition of HS-DSCH/DCH -> PCH1. UL&DL Traffic Volume based2. Support PCH

Transition of HS-DSCH/E-DCH -> PCH1. UL&DL Traffic Volume Based2. Support PCH

Transition DCH/DCH -> HS-DSCH/E-DCH1. UL/DL Traffic Volume Based2. Channel Quality Measure Based (Option)3. UE &Cell Capability4. Compressed Mode is not started

Transition DCH/DCH -> HS-DSCH/DCH1. UL/DL Traffic Volume Based2. Channel Quality Measure Based (Option)3. UE &Cell Capability

Transition HS-DSCH/E-DCH -> DCH/DCH1. Channel Quality Measure Based (Option)

Transition HS-DSCH/DCH -> DCH/DCH1. Channel Quality Measure Based (Option)

Transition HS-DSCH/DCH -> HS-DSCH/E-DCH1. UL Traffic Volume Based2. UE &Cell Capability3. If HSUPA associate compressed mode method is set to “ Serial” , the compressed mode is not started

Transition of FACH/RACH -> IDLE1. UL&DL Traffic Volume Based

Transition of DCH/DCH ->IDLE1. UL&DL Traffic Volume Based

Transition of HS-DSCH/DCH -> IDLE1. UL&DL Traffic Volume Based

Transition of HS-DSCH/E-DCH -> IDLE1. UL&DL Traffic Volume Based

Transition of PCH->IDLE1. DL&UL Traffic Volume Based

Transition of FACH/RACH -> PCH1. UL&DL Traffic Volume Based2. Support PCH

Transition of PCH -> FACH/RACH1. UL/DL Traffic Volume Based

HS-DSCH /E-DCH or

HS-DSCH/DCH

Measurement and Events HSUPA support ：

CELL_DCH(DL HS-DSCH/UL E-DCH)<->CELL_FACH—triggered by traffic(dual directions)

CELL_DCH (DL HS-DSCH/UL E-DCH)<->CELL_DCH(DL DCH/UL DCH)

triggered by traffic - DL DCH/UL DCH->DL HS-DSCH/UL E-DCH

triggered by signal quality DL HS-DSCH/UL E-DCH->DL DCH/UL DCH

triggered by mobility DL HS-DSCH/UL E-DCH<->DL DCH/UL DCH or DL HS-DSCH/UL DCH

CELL_DCH (DL HS-DSCH/UL E-DCH)<->URA_PCH CELL_DCH (DL HS-DSCH/UL E-DCH)->IDLE

Configuration Parameter

Configuration Parameter

DRBC Procedure

1F event DchE4bThd

FToPchThd

PchHoldTimeThr 600s

FToIdleThd

Time to trigger for 4b=2560ms

Pending Time=16000ms

By default, PCH Channel is not enabled

Cell_FACHCell_FACH

Time to trigger for 4b=2560ms

Pending Time=16000ms

Cell_DCH/Cell_DCH/HS-DSCH

HsToFtimesThr

HS-DSCH/EHS-DSCH/E

DToIdleThd

UP 4B&UE 4BUP 4B&UE 4B

UP 4B0&UE 4B0UP 4B0&UE 4B0

DToIdleThd

UP 4B0&UE 4B0UP 4B0&UE 4B0

UP 4B0&UE 4B0UP 4B0&UE 4B0