wcdma ran11 dccc algorithm and parameters

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Confidential Information of Huawei. No Spreading Without Permission

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www.huawei.com

Copyright 2009 Huawei Technologies Co., Ltd. All rights reserved.

WCDMA DCCC Algorithm and

Parameters

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Page2Copyright 2009 Huawei Technologies Co., Ltd. All rights reserved.

Foreword

z Rate control triggers rate decrease, rate increase, or handover

according to the resource consumption conditions to ensure

the QoS, maintain system stability, and improve system capacity

z Rate control in the WCDMA system is applicable to the

following services:

Adaptive Multi Rate (AMR) services

Adaptive Multi Rate - Wideband (AMR-WB) services

Best Effort (BE) services

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References

z 3GPP TS 25.331: Radio Resource Control (RRC)

z 3GPP TS 25.413: UTRAN Iu interface RANAP signalling

z 3GPP TS 25.415: UTRAN Iu interface user plane protocols

z 3GPP TS 25.433: UTRAN Iub interface NBAP signalling

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Objectives

z Upon completion of this course, you will be able to:

Explain the principle of DCCC

Describe the realization method of DCCC

Perform the parameter adjustment of DCCC

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Contents

1. DCCC Overview

2. DCCC Based on Traffic Volume

3. DCCC Based on Throughput

4. DCCC Based on Link Stability

5. DCCC Based on Basic Congestion

6. UE State Transition

7. Always Online

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Contents

1. DCCC Overview






7. Always Online

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DCCC Description

z DCCC: Dynamic Channel Configuration Control

z DCCC allocates dynamically resources according to the service

request and system load. So, DCCC is an effective method to

increase the radio resource utilization efficiency

z The UL DCCC algorithm and the DL DCCC algorithm work

independently

z The DCCC function is controlled by the subparameter DRA_DCCC_SWITCH of the

parameter DraSwitch.

z The UL DCCC function is invalid for the BE service whose maximum UL rate is below or

equal to the UL rate threshold for DCCC specified by UlDcccRateThd. Thus, excessive

signaling procedures can be avoided. The DL rate is limited in the same way. The DL rate

threshold is specified by DlDcccRateThd.

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Parameters of DCCC

z DraSwitch-DRA_DCCC_SWITCH

Parameter name: Dynamic resource allocation switch for DCCC

function

Recommended value: ON

z UlDcccRateThd/DlDcccRateThd

Parameter name: Uplink/Downlink Bit Rate Threshold For DCCC

Recommended value: 64kbit/s, 64kbit/s

z DraSwitch-DRA_DCCC_SWITCH

Content: When the switch is on, the dynamic channel reconfiguration control

algorithm is used for the RNC.

Value range: OFF, ON

Physical value range: 0, 1

Set this parameter through SET CORRMALGOSWITCH.

z UlDcccRateThd/DlDcccRateThd

Content: For a BE service that has a low maximum rate, the DCCC algorithm is not

obviously effective yet it increases algorithm processing. Thus, the traffic-based

DCCC algorithm is applied to BE services whose maximum UL/DL rate is greater

than the threshold.

Value range: D8, D16, D32, D64, D128, D144, D256, D384

Physical value range: 8, 16, 32, 64, 128, 144, 256, 384

Physical unit: kbit/s

Set these parameters through SET DCCC.

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Contents

1. DCCC Overview






7. Always Online

z Rate adjustment based on traffic volume only applies to R99 BE services.

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Contents


2.1 Traffic Volume Measurement and Event Reporting

2.2 Rate Adjustment Based on Traffic Volume

2.3 Signaling Procedure

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Traffic Volume Measurement Item

z In the uplink, the UE measures Dedicated Traffic Channel

(DTCH), (that is, buffer usage of RLC entities), to obtain the

uplink traffic volume

z In the downlink, the RNC measures the DTCH, (that is, buffer

usage of RLC entities), to obtain the downlink traffic volume

z The traffic volume is measured by the buffer usage of the RLC entity. The RNC increases or

decreases the rate of BE services based on the traffic volume to avoid excessively high or

low traffic volume.

z The traffic volume measurements defined in 3GPP TS 25.331 are applicable to only the UL.

For the DL, traffic volume measurements and associated rate adjustment are designed and

implemented by Huawei.

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Traffic Volume Measurement Event

z Event 4a:

Traffic volume is above a threshold for a period of time

z Event 4b:

Traffic volumes is below a threshold for a period of time

z In the UL, the UTRAN sends to the UE the absolute threshold, time to trigger event 4a or

4b, and pending time after trigger through a MEASUREMENT CONTROL message. The UE

sends a report on event 4a or 4b through a MEASUREMENT REPORT message.

z In the DL, measurement control is also performed through messages. The difference is that

all the interactions occur within the RNC in the DL.

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Event 4a

z Event 4a triggered by an increase in the transport channel

traffic volume:

z In the uplink:

When the traffic volume is higher than the value of Event4aThd for a period of

time defined by TimetoTrigger4A, the UE reports an event 4a. No more events 4a

are reported during the time defined by PendingTime4A.

z In the downlink:

When the traffic volume is higher than the value of Event4aThd for a period of

time defined by TimetoTrigger4A, the RNC reports internally an event 4a. No more

events 4a are reported during the time defined by PendingTime4A.

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Event 4b

z Event 4b triggered by a decrease in the transport channel traffic

volume:

z In the uplink:

When the traffic volume is lower than the value of Event4bThd for a period of time

defined by TimetoTrigger4B, the UE reports an event 4b. No more events 4b are

reported during the time defined by PendingTime4B.

z In the downlink:

When the traffic volume is lower than the value of Event4bThd for a period of time

defined by TimetoTrigger4B, the RNC reports internally an event 4b. No more

events 4b are reported during the time defined by PendingTime4B.

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Parameters of Traffic Volume

4000ms4000msPending time after trigger 4B PendingTime4B

2560ms2560msTime to trigger 4B TimetoTrigger4B

256bytes256bytesTraffic Measurement Event 4B

threshold Event4bThd

4000ms4000msPending time after trigger 4A PendingTime4A

240ms240msTime to trigger 4A TimetoTrigger4A

1024bytes1024bytesTraffic Measurement Event 4A

threshold Event4aThd

Recommended Value in DL

RecommendedValue in UL

Parameter NameParameter

z Recommended values of event 4a and event 4b:

z Rate adjustment based on traffic volume takes effect in the UL and DL separately.

Associated parameters are configured in the UL and DL separately.

z Set these parameters through ADD TYPRABDCCCMC/MOD TYPRABDCCCMC.

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Contents

2. Rate Reallocation Based on Traffic Volume




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Rate Adjustment Strategy

z In Huawei implementation, two strategies are available for DCH

rate adjustment based on traffic volume:

RATE_UP_AND_DOWN_ON_DCH

RATE_UP_ONLY_ON_DCH

z DcccStg

Parameter name: DCCC strategy

Recommended value: RATE_UP_AND_DOWN_ON_DCH

z The RATE_UP_AND_DOWN_ON_DCH strategy means that the rate can be either

downsized or upsized. When the system resources in the network are insufficient, the

RATE_UP_AND_DOWN_ON_DCH strategy is recommended.

z The RATE_UP_ONLY_ON_DCH strategy means that the rate can only be upsized. When

the network resources are sufficient, the RATE_UP_ONLY_ON_DCH strategy is

recommended.

z DcccStg

Content: This parameter defines the strategy of adjusting the data rate of PS BE

services when the UE is in CELL_DCH state.

RATE_UP_AND_DOWN_ON_DCH: Data rate upsizing and rate downsizing are

allowed.

RATE_UP_ONLY_ON_DCH: Only data rate upsizing is allowed. It means that the

state of UE transits from CELL_DCH to CELL_FACH when the 4b event is reported.

Value range: RATE_UP_AND_DOWN_ON_DCH, RATE_UP_ONLY_ON_DCH

Physical value range: RATE_UP_AND_DOWN_ON_DCH, RATE_UP_ONLY_ON_DCH

Set this parameter through SET DCCC.

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Rate Adjustment Strategy in UL

z Principles of RATE_UP_AND_DOWN_ON_DCH in UL:

Rate upsizing is performed if the RNC receives a report of event 4a

about the uplink traffic volume

Rate downsizing is performed if the RNC receives a report of event

4b about the uplink traffic volume

z After receiving a report on event 4a, the RNC triggers rate increase. After receiving a

report on event 4b, the RNC triggers rate decrease. The minimum value to which the rate

can be decreased is the UL rate threshold for DCCC (UlDcccRateThd). The maximum value

to which the rate can be increased is the MBR, which is Min{ the requested maximum bit

rate assigned by the CN, the maximum rate supported by UE capabilities}.

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Rate Adjustment Strategy in UL (Cont.)

z Principles of RATE_UP_ONLY_ON_DCH in UL:


about the uplink traffic volume

Rate downsizing is prohibited. If a UE is in low activity, the state of

the UE is directly transited to CELL_FACH if the UE state transition

algorithm is enabled

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UL Rate Increase Procedure

z If the UL rate increase level is 2_Rates and the current rate is below

the UlDcccRateThd, the current rate is increased to the

UlDcccRateThd. If the current rate is above or equal to the

UlDcccRateThd and lower than the MBR, the current rate is increased

to the MBR

z If the UL rate increase level is 3_Rates and the current rate is below

the UlDcccRateThd, the rate is increased to the UlDcccRateThd. If the

current rate is equal to the UlDcccRateThd, the current rate is

increased to the UL middle rate threshold and then to the MBR. If the

current rate is lower than the MBR but higher than the

UlDcccRateThd, the current rate is increased to the MBR

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UL Rate Decrease Procedure

z If the UL rate decrease level is 2_Rates, the rate is decreased

directly to the UlDcccRateThd

z If the UL rate decrease level is 3_Rates and the current rate is

the MBR, the current rate is decreased to the UL middle rate

threshold and then to the UlDcccRateThd. If the current rate is

lower than the MBR but higher than the UlDcccRateThd, the

current rate is decreased to the UlDcccRateThd

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Example of UL Rate Adjustment

z Rate adjustment when the UL rate increase and decrease level

are 2_Rates:

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Example of UL Rate Adjustment (Cont.)

z Rate adjustment when the UL rate increase and decrease level

are 3_Rates:

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Parameters of Traffic Volume (Cont.)

z UlRateUpAdjLevel

Parameter name: Uplink Rate Increase Adjust Level

Recommended value: 3_Rates

z UlRateDnAdjLevel

Parameter name: Uplink Rate Decrease Adjust Level


z UlRateUpAdjLevel

Content: This parameter determines whether the UL rate is raised to the maximum

rate in one step or two steps for BE service set up on DCH in uplink.

Value range: 2_Rates, 3_Rates

Physical value range: 2_Rates, 3_Rates


z UlRateDnAdjLevel

Content: This parameter determines whether the UL rate is lowered to the

minimum rate in one step or two steps for BE service set up on DCH in uplink.




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z UlMidRateCalc

Parameter name: Uplink Mid Bit Rate Calculate Method

Recommended value: HAND_APPOINT

z UlMidRateThd

Parameter name: Uplink Mid Bit Rate Threshold

Recommended value: D128, namely 128kbit/s

z UlMidRateCalc

Content: This parameter determines whether automatic or manual mode is used

for 3-step adjustment of the uplink intermediate rate.

Value range: AUTO_CALC, HAND_APPOINT

Physical value range: AUTO_CALC, HAND_APPOINT


z UlMidRateThd

Content: Threshold of the UL intermediate rate when the 3-step mode is used for

UL rate adjustment and the manual mode is used for UL intermediate rate

adjustment.

Value range: D16, D32, D64, D128, D144, D256, D384

Physical value range: 16, 32, 64, 128, 144, 256, 384



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Rate Adjustment Strategy in DL

z Principles of RATE_UP_AND_DOWN_ON_DCH in DL:


about the downlink traffic volume

Rate downsizing is performed if the RNC receives a report of event

4b about the downlink traffic volume

z After receiving a report on event 4a, the RNC triggers rate increase. After receiving a

report on event 4b, the RNC triggers rate decrease. The minimum value to which the rate

can be decreased is the DL rate threshold for DCCC (DlDcccRateThd). The maximum value

to which the rate can be increased is the MBR, which is Min{ the requested maximum bit

rate assigned by the CN, the maximum rate supported by UE capabilities}.

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Rate Adjustment Strategy in DL (Cont.)

z Principles of RATE_UP_ONLY_ON_DCH in DL:


about the downlink traffic volume

Rate downsizing is prohibited. If a UE is in low activity, the state of

the UE is directly transited to CELL_FACH if the UE state transition

algorithm is enabled

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DL Rate Increase Procedure

z If the DL rate increase level is 2_Rates and the current rate is below

the DlDcccRateThd, the current rate is increased to the

DlDcccRateThd. If the current rate is above or equal to the

DlDcccRateThd and lower than the MBR, the current rate is increased

to the MBR

z If the DL rate increase level is 3_Rates and the current rate is below

the DlDcccRateThd, the rate is increased to the DlDcccRateThd. If the

current rate is equal to the DlDcccRateThd, the current rate is

increased to the DL middle rate threshold and then to the MBR. If the

current rate is lower than the MBR but higher than the

DlDcccRateThd, the current rate is increased to the MBR

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DL Rate Decrease Procedure

z If the DL rate decrease level is 2_Rates, the rate is decreased

directly to the DlDcccRateThd

z If the DL rate decrease level is 3_Rates and the current rate is

the MBR, the current rate is decreased to the DL middle rate

threshold and then to the DlDcccRateThd. If the current rate is

lower than the MBR but higher than the DlDcccRateThd, the

current rate is decreased to the DlDcccRateThd

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z DlRateUpAdjLevel

Parameter name: Downlink Rate Increase Adjust Level


z DlRateDnAdjLevel

Parameter name: Downlink Rate Decrease Adjust Level


z DlRateUpAdjLevel

Content: This parameter determines whether the DL rate is raised to the maximum

rate in one step or two steps for BE service set up on DCH in downlink.




z DlRateDnAdjLevel

Content: This parameter determines whether the DL rate is lowered to the

minimum rate in one step or two steps for BE service set up on DCH in downlink.




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z DlMidRateCalc

Parameter name: Downlink Mid Bit Rate Calculate Method

Recommended value: HAND_APPOINT

z DlMidRateThd

Parameter name: Downlink Mid Bit Rate Threshold


z DlMidRateCalc

Content: This parameter determines whether automatic or manual mode is used

for 3-step adjustment of the downlink intermediate rate.

Value range: AUTO_CALC, HAND_APPOINT

Physical value range: AUTO_CALC, HAND_APPOINT


z DlMidRateThd

Content: Threshold of the DL intermediate rate when the 3-step mode is used for

DL rate adjustment and the manual mode is used for DL intermediate rate

adjustment.

Value range: D16, D32, D64, D128, D144, D256, D384

Physical value range: 16, 32, 64, 128, 144, 256, 384



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Contents

2. Rate Reallocation Based on Traffic Volume




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Signaling Procedure

z Signaling procedure of UL rate upsizing based on traffic volume:

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Signaling Procedure (Cont.)

z Signaling procedure of UL rate downsizing based on traffic

volume:

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z Signaling procedure of DL rate upsizing based on traffic volume:

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z Signaling procedure of DL rate downsizing based on traffic

volume:

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Contents

1. DCCC Overview






7. Always Online

z Rate adjustment based on throughput applies to HSUPA and R99 BE services.

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Contents


3.1 Throughput Measurement and Event Reporting

3.2 Rate Adjustment Based on Throughput


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Throughput Measurement Item

z In each measurement period, the MAC-d measures the traffic

volume of radio bearers (RBs). Then, it divides the measurement

result by the measurement period to obtain the throughput

To enable throughput-based rate adjustment on the DCH, set the

subparameter DRA_THROUGHPUT_DCCC_SWITCH of the

parameter DraSwitch to ON

To enable throughput-based rate adjustment for HSUPA, set the

subparameter DRA_HSUPA_DCCC_SWITCH of the parameter

DraSwitch to ON

z Throughput is the traffic volume in a measurement period. The RNC adjusts the rate of BE

services based on the throughput.

For HSUPA BE services, the RNC performs rate decrease or rate increase based on

the throughput.

For DCH BE services, the RNC performs rate decrease only when the throughput is

excessively high.

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Throughput Measurement Event

z Event 4a:

Throughput is above a threshold for a period of time

z Event 4b:

Throughput is below a threshold for a period of time

z For throughput-based rate adjustment on the E-DCH, both events 4a and 4b apply, that is,

both rate upsizing and downsizing are applicable for both uplink and downlink.

z For throughput-based rate adjustment on the DCH, only event 4b applies, that is, only rate

downsizing is applicable.

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Throughput Measurement Event (Cont.)

z Mechanism of measuring the throughput and reporting events

4a and 4b:

z The throughput measurement period can be specified by the parameter

E2FThrouMeasPeriod for services on the E-DCH and DchThrouMeasPeriod for services on

the DCH

z Assume that AvgThroughput represents the throughput of an RB during a measurement

period. Then:

If the AvgThroughput is above the threshold of event 4a for a period of time

specified by EdchTimetoTrigger4A and the current time is not in the pending time

after trigger, then event 4a is triggered. After event 4a is triggered, it cannot be

triggered any more in the period of time specified by EdchPendingTime4A.

If the AvgThroughput is below the threshold of event 4b for a period of time

specified by EdchTimetoTrigger4B or DchThrouTimetoTrigger4B and the current

time is not in the pending time after trigger, then event 4b is triggered. After event

4b is triggered, it cannot be triggered any more in the period of time specified by

EdchPendingTime4B or DchThrouPendingTime4B.

z The previous figure shows the mechanism of measuring the throughput and reporting

events 4a and 4b. In this example, the time to trigger event 4a or 4b is three consecutive

measurement periods, and the pending time after trigger is four consecutive measurement

periods.

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Rate Adjustment Set

z Compared with R99 service, HSUPA can support higher bit rate.

Usually there is big gap between maximum and minimum bit

rate. To utilize the rate adjustment effectively, some middle bit

rate levels and associated thresholds need to be added. We call

all the bit rates and thresholds as a Rate Adjustment Set, just

like {(Rmin, TRmin), (R1, TR1 ), , (Rmax,TRmax)}

z If the subscribed MBR is bigger than Rmin, the DCCC algorithm

is on. Otherwise, the DCCC algorithm will not work

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The mechanism of reporting events 4a and 4b about throughput is as follows:

z Assume that a set of adjustment rates and associated throughput thresholds is: {(R1, TR1), ... (Ri, TRi), ... (RN, TRN)}

For services on the E-DCH:

The first variable in each pair of parentheses represents the HSUPA adjustment rate specified by the EdchRateAdjustSet parameter.

The second variable in each pair of parentheses represents the throughput threshold corresponding to the adjustment rate.

TRi = Ri x (Threshold rate ratio). For different threshold rate ratios, see the following table.

RN represents the maximum adjustment rate specified by the EdchRateAdjustSet parameter.

Assume that RMaxRate represents the MBR assigned for a service through an RAB ASSIGNMENT REQUEST message. Then, TRMaxRate = RMaxRate x (Threshold rate ratio)MaxRate.

If Rt < RMaxRate Rt+1 (1 t N1), the set of HSUPA adjustment rates and associated throughput thresholds is: {(R1, TR1), ..., (Ri, TRi), ..., (Rt, TRt), ( RMaxRate, TRMaxRate)}.

If RMaxRate > RN, the set of HSUPA adjustment rates and associated throughput thresholds is: {(R1, TR1), ..., (Ri, TRi), ..., (RN, TRN), (RMaxRate, TRMaxRate)}.

For services on the DCH, the adjustment rate set is {rate threshold for DCCC, middle rate, maximum rate}.

The rate threshold for DCCC is specified by the UlDcccRateThd or DlDcccRateThd parameter.

The middle rate is determined by the UlMidRateCalc or DlMidRateCalcparameter and the UlMidRateThd or DlMidRateThd parameter.

The maximum rate is the MBR.

The throughput threshold is as follows: Rt = Rt x 90%.

70%2890 kbit/s, 5760kbit/s

75%384 kbit/s, 608kbit/s, 1450kbit/s, 2048kbit/s

80%128 kbit/s, 144kbit/s, 256kbit/s

90%8 kbit/s, 16 kbit/s, 32 kbit/s, 64 kbit/s

Threshold Rate RatioRate

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Threshold for Triggering Events 4a/4b

z In the aspect of DCCC for HSUPA service:

The threshold of 4a is the throughput threshold associated with

the current HSUPA adjustment rate, that is, TRt

TRt = Rt * (threshold rate ratio)t

The threshold of 4b is the throughput threshold associated with

the latest HSUPA adjustment rate, that is, TRt1

TRt1 = Rt1 * (threshold rate ratio)t1

z Here:

Rt is the current rate in the HSUPA rate adjustment set.

Rt-1 is the latest rate in the HSUPA rate adjustment set.

Threshold rate ratiot and threshold rate ratiot-1 are defined by the table of previous

page.

z If the current HSUPA adjustment rate is the minimum rate, the threshold of event 4b is the

threshold rate of E-DCH to FACH state transition (E2FThrouThd).

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Threshold for Triggering Events 4a/4b (Cont.)z In the aspect of DCCC for DCH service:

The threshold of 4b is the throughput threshold associated with

the latest DCH adjustment rate, that is, TRt1

TRt1 = Rt1 * (threshold rate ratio)t1

z Here:

Rt-1 is the latest rate in the DCH rate adjustment set.

Threshold rate ratiot-1 is set to 90%.

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Parameters of Throughput

z DraSwitch-DRA_HSUPA_DCCC_SWITCH

Parameter name: Dynamic resource allocation switch for HSUPA

DCCC function

Recommended value: ON

z DraSwitch-DRA_THROUGHPUT_DCCC_SWITCH

Parameter name: Dynamic resource allocation switch for

throughput-based DCCC function

Recommended value: OFF

z DraSwitch-DRA_HSUPA_DCCC_SWITCH

Content: When the switch is on, the DCCC algorithm is used for HSUPA. The DCCC

switch must be also on before this switch takes effect.




z DraSwitch-DRA_THROUGHPUT_DCCC_SWITCH

Content: When the switch is on, the DCCC based on traffic statistics is supported

over the DCH.




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Parameters of Throughput (Cont.)

z E2FThrouMeasPeriod

Parameter name: E-DCH Throu Meas Period

Recommended value: 30, namely 300ms

z DchThrouMeasPeriod

Parameter name: DCH Throu Meas Period


z E2FThrouMeasPeriod

Content: Period of E-DCH throughput ratio measurement. This parameter specifies

the period of E-DCH throughput ratio measurement. The throughput ratio over the

E-DCH is periodically measured to implement state transition from E-DCH to FACH

and DCCC algorithm on EDCH.

Value range: 1~10000

Physical value range: 10~100000; step: 10

Physical unit: ms

Set this parameter through SET UESTATETRANS.

z DchThrouMeasPeriod

Content: This parameter specifies the period of DCH throughput ratio

measurement. Macd performs statistic of traffic volume on DCH and reports 4B

events which are used for the rate decrease process of BE service set up on DCH.

Value range: 1~1000

Recommended value: 10~10000; step: 10

Physical unit: ms


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16, 16Period Amount after trigger 4B on DCH

DchThrouPendingTime4B

2, 2Period Amount to trigger 4B on DCH

DchThrouTimetoTrigger4B

DCH

16, nonePeriod Amount after trigger 4B on EDCH

EdchPendingTime4B

2, nonePeriod Amount to trigger 4B on EDCH

EdchTimetoTrigger4B

16, nonePeriod Amount after trigger 4A on EDCH

EdchPendingTime4A

2, nonePeriod Amount to trigger 4A on EDCH

EdchTimetoTrigger4A

HSUPA

Recommended Value in UL/DL

Parameter NameParameterService Type

z Recommended values of event 4a and event 4b:

z For EDCH, rate adjustment based on throughput takes effect in the UL. So the associated

parameters are configured in the UL only.

z For DCH, rate adjustment based on throughput takes effect in the UL and DL separately.

So the associated parameters are configured in the UL and DL separately.

z Set these parameters through ADD TYPRABDCCCMC/MOD TYPRABDCCCMC.

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z EdchRateAdjustSet

Parameter name: HSUPA UpLink Rate Adjust Set

Recommended value:

RATE_8KBPS-0, RATE_16KBPS-0, RATE_32KBPS-0, RATE_64KBPS-0,

RATE_128KBPS-1, RATE_144KBPS-0, RATE_256KBPS-1, RATE_384KBPS-

0, RATE_608KBPS-1, RATE_1440KBPS-0, RATE_2048KBPS-0,

RATE_2880KBPS-0, RATE_5740KBPS-0

z EdchRateAdjustSet

Content: HSUPA UL rate adjustment set. It contains rates for rate adjustment and is

used in the HSUPA DCCC algorithm.

Value range: RATE_8KBPS, RATE_16KBPS, RATE_32KBPS, RATE_64KBPS,

RATE_128KBPS, RATE_144KBPS, RATE_256KBPS, RATE_384KBPS, RATE_608KBPS,

RATE_1440KBPS, RATE_2048KBPS, RATE_2880KBPS, RATE_5740KBPS

Physical value range: 8, 16, 32, 64, 128, 144, 256, 384, 608, 1440, 2048, 2880,

5740


Set this parameter through SET EDCHRATEADJUSTSET.

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z E2FThrouThd

Parameter name: E-DCH2F 4B Threshold

Recommended value: 8, namely 8kbit/s

z E2FThrouThd

Content: This parameter is used to check whether the UE in the low activity state.

If the UE is on the E-DCH channel, the low activity counter increases by 1 every

time throughput ratio event 4B is reported.

Value range: 0~384



Set this parameter through SET UESTATETRANS.

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Contents





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Rate Adjustment Strategy

z In Huawei implementation, two strategies are available for

EDCH rate adjustment based on throughput:

RATE_UP_AND_DOWN_ON_EDCH

RATE_UP_ONLY_ON_EDCH

z For DCH rate adjustment based on throughput, only rate

downsizing is applicable

z The RATE_UP_AND_DOWN_ON_EDCH strategy means that the rate can be both

downsized and upsized. If the system resources in the network are insufficient, the

RATE_UP_AND_DOWN_ON_EDCH strategy is recommended.

z The RATE_UP_ONLY_ON_EDCH strategy means that the rate can only be upsized. When

the network resources are sufficient, the RATE_UP_ONLY_ON_EDCH strategy is

recommended.

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z HsupaDcccStg

Parameter name: HSUPA DCCC Strategy

Recommended value: RATE_UP_AND_DOWN_ON_EDCH

z HsupaDcccStg

Content: Strategy of the UE for rate adjustment over the EDCH.

RATE_UP_AND_DOWN_ON_EDCH indicates that the rate over the EDCH can be

raised or lowered. RATE_UP_ONLY_ON_EDCH indicates that the rate over the

EDCH can only be raised, which means that the UE can switch to the FACH state at

any rate.

Value range: RATE_UP_AND_DOWN_ON_EDCH, RATE_UP_ONLY_ON_EDCH

Physical value range: RATE_UP_AND_DOWN_ON_EDCH,

RATE_UP_ONLY_ON_EDCH


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N-54


Rate Adjustment Procedure for EDCH

z Principles of RATE_UP_AND_DOWN_ON_EDCH:

After a report on event 4a is received, the rate is increased by one level,

that is, from Rt to Rt+1. If the current rate is the MBR, no action is required

After a report on event 4b is received, the rate is decreased to a rate that

is close to the corresponding throughput. If the reported throughput is TR

and TRi1 < TR < TRi, then the RB adjustment rate is Ri

Course Name


N-55


Rate Adjustment Procedure for EDCH (Cont.)z Principles of RATE_UP_ONLY_ON_EDCH:

After a report on event 4a is received, the rate is increased by one

level, that is, from Rt to Rt+1. If the current rate is the MBR, no

action is required

After a report on event 4b is received, rate decrease is not

performed. Instead, state transition is performed according to the

principles described in section 6 "UE State Transition"

Course Name


N-56


Rate Adjustment Procedure for DCH

z After a report on event 4b is received, the rate is decreased to a

rate that is close to the corresponding throughput. If the

reported throughput is TR and TRi1 < TR < TRi, then the RB

adjustment rate is Ri

z The above process applies to both uplink and downlink

Course Name


N-57


Contents

3. Rate Reallocation Based on Throughput




Course Name


N-58


Signaling Procedure

z Signaling procedure of rate increase based on throughput:

Course Name


N-59



z Signaling procedure of rate decrease based on throughput:

z Throughput-based rate adjustment on the DCH is implemented through the signaling on

the Uu and Iub interfaces.

z Only rate decrease can be implemented by this algorithm.

Course Name


N-60


Contents

1. DCCC Overview






7. Always Online

z Rate adjustment based on link stability only applies to R99 BE services.

Course Name


N-61


Contents


4.1 Uplink Stability Measurement and Event Reporting

4.2 Downlink Stability Measurement and Event Reporting

4.3 Rate Adjustment Based on Uplink Stability

4.4 Rate Adjustment Based on Downlink Stability


Course Name


N-62


Uplink Stability Measurement Item

z UL stability measurement involves two measurement items: UL

TX power of the UE and UL BLER

The UL TX power of the UE is measured on the Uu interface. If the

UL TX power reaches the maximum power, you can infer that the

radio link is unstable

The UL BLER is measured by the RNC. If the UL BLER is excessively

high, you can infer that the radio link is unstable

z Link stability is measured through the UE TX power or BLER in the UL. The RNC performs

rate decrease or rate increase for R99 BE services based on the link stability.

Course Name


N-63


Uplink Stability Measurement Event

z UL TX power of the UE:

Event 6A (6A1/6A2): The UE TX power is above a certain threshold for a

period of time

Event 6B (6B1/6B2): The UE TX power is below a certain threshold for a

period of time

Event 6D: The UE TX power is equal to the maximum allowed TX power

for a period of time

z UL BLER:

Event 5A: The number of error blocks during the sliding window is greater

than or equal to a predefined number

z After establishing an BE service, the RNC sends the following information specified by

switch setting to the UE through a MEASUREMENT CONTROL message:

Threshold of event 6A1, 6B1, 6A2, 6B2, or 6D for TX power.

Time to trigger event 6A1, 6B1, 6A2, 6B2, or 6D.

z Then, the UE measures the TX power in real time, filters the measurement results.

z Each time a measurement event is triggered, the UE sends a measurement event report to

the UTRAN through a MEASUREMENT REPORT message. Then, the UL stability function

performs corresponding control tasks according to the report.

z The UL stability control switch setting:

When BeUlEvTrigInd is set to SINGLE and BeUlQos6A1McSwitch is set to YES,

event 6A1 triggers UL stability control.

When BeUlEvTrigInd is set to SINGLE and BeUlQos5AMcSwitch is set to YES, event

5A triggers UL stability control.

When BeUlEvTrigInd is set to COMBINE, events 6A1 and 5A together trigger UL

stability control.

When BeUlQos6DMcSwitch is set to ON, event 6D triggers UL stability control.

Course Name


N-64


Parameters of Link Stability

z BeUlEvTrigInd

Parameter name: Indicator For BE Uplink QOS Event

Recommended value: SINGLE

z BeUlEvTrigInd

Content: For BE service, When the parameter is set to SINGLE, an UL event 6A1 or

5A can independently trigger the QOS enhancement action. The 6A1, 5A switch

settings decide whether to perform 6A1 or 5A measurement control. When the

parameter is set to COMBINE, only combined events 6A1+5A can trigger the QOS

enhancement action, and whether to perform 6A1 and 5A measurement is not

controlled by the 6A1 and 5A measurement switch.

Value range: SINGLE, COMBINE

Physical value range: SINGLE, COMBINE

Set this parameter through SET QOSACT.

Course Name


N-65


Parameters of Link Stability (Cont.)

z BeUlQos6A1McSwitch

Parameter name: Measurement Of 6A1 Switch

Recommended value: YES

z BeUlQos5AMcSwitch

Parameter name: Measurement Of 5A Switch


z BeUlQos6DMcSwitch

Parameter name: Measurement Of 6D Switch

Recommended value: NO

z BeUlQos6A1McSwitch

Content: Event 6A1 measurement switch when BeUlEvTrigInd is set to SINGLE for

BE service. If this parameter is set to YES, event 6A1 measurement is delivered.

Value range: NO, YES

Physical value range: NO, YES

z BeUlQos5AMcSwitch

Content: Event 5A measurement switch when BeUlEvTrigInd is set to SINGLE for BE

service. If this parameter is set to YES, event 5A measurement is delivered.



z BeUlQos6DMcSwitch

Content: UL event 6D measurement switch for BE service. If this parameter is set to

YES, event 6D measurement is delivered.



z Set these parameters through SET QOSACT.

Course Name


N-66


Events 6A and 6B

z Events 6A1, 6A2, 6B1 and 6B2:

z As shown in the above figure, the maximum UL TX power for BE services is specified by

the parameter MaxUlTxPowerforInt or MaxUlTxPowerforBac. Delta_6a1, Delta_6b1,

Delta_6a2, and Delta_6b2 are relative thresholds, which are the differences between the

absolute thresholds of events 6A1, 6B1, 6A2, and 6B2 for TX power and the maximum UL

TX power of BE service. They are specified by the parameters UlThd6A1, UlThd6B1,

UlThd6A2, and UlThd6B2 respectively.

z The absolute thresholds are calculated according to the following formulas:

Threshold of event 6A1 for TX power = MaxUlTxPowerforInt/Bac UlThd6A1

Threshold of event 6B1 for TX power = MaxUlTxPowerforInt/Bac UlThd6B1

Threshold of event 6A2 for TX power = MaxUlTxPowerforInt/Bac UlThd6A2

Threshold of event 6B2 for TX power = MaxUlTxPowerforInt/Bac UlThd6B2

z If the UE TX power is above the threshold of event 6A1 for TX power for a period of time

specified by UlBeTrigTime6A1, event 6A1 is triggered.

z If the UE TX power is below the threshold of event 6B1 for TX power for a period of time

specified by UlBeTrigTime6B1, event 6B1 is triggered.

z If the UE TX power is above the threshold of event 6A2 for TX power for a period of time

specified by UlBeTrigTime6A2, event 6A2 is triggered.

z If the UE TX power is below the threshold of event 6B2 for TX power for a period of time

specified by UlBeTrigTime6B2, event 6B2 is triggered.

Course Name


N-67


Event 6D

z Event 6D:

z As shown in the above figure, the maximum UL TX power for BE services is specified by

the parameter MaxUlTxPowerforInt or MaxUlTxPowerforBac.

z If the UE TX power is equal to the maximum UL TX power for a period of time specified by

UlBeTrigTime6D, event 6D is triggered.

Course Name


N-68



z MaxUlTxPowerforInt

Parameter name: Max UL TX power of interactive service

Recommended value: 24, namely 24dBm

z MaxUlTxPowerforBac

Parameter name: Max UL TX power of background service

Recommended value: 24, namely 24dBm

z MaxUlTxPowerforInt

Content: The maximum UL transmit power for the interactive service in a specific cell. It is

based on the UL coverage requirement of the interactive service designed by the network

planning. The larger the value of this parameter is, the wider the coverage of the

corresponding services will be. When the downlink coverage is exceeded, the uplink

coverage and downlink coverage of the service will become unbalanced. If the values of

these parameters are too small, the uplink coverage will probably be smaller than the

downlink coverage of the service.

Value range: -50~33

Physical value range: -50~33; step: 1

Physical unit: dBm

Set this parameter through ADD CELLCAC.

z MaxUlTxPowerforBac

Content: The maximum UL transmit power for background service in a specific cell. It is

based on the UL coverage requirement of the background service designed by the network

planning. The larger the value of this parameter is, the wider the coverage of the

corresponding services will be. When the downlink coverage is exceeded, the uplink

coverage and downlink coverage of the service will become unbalanced. If the values of

these parameters are too small, the uplink coverage will probably be smaller than the

downlink coverage of the service.

Value range: -50~33

Physical value range: -50~33; step: 1

Physical unit: dBm

Set this parameter through ADD CELLCAC.

Course Name


N-69



z UlThd6A1/UlThd6B1/UlThd6A2/UlThd6B2

Parameter name:

Uplink Event 6A1/6B1/6A2/6B2 Relative Threshold

Recommended value:

None, none, none, none

z UlThd6A1/UlThd6B1/UlThd6A2/UlThd6B2

Content: Measurement reporting threshold for triggering event 6A1/6B1/6A2/6B2/6D.

Value range: 0~82


Physical unit: dB

Set these parameters through ADD TYPRABQUALITYMEAS.

Course Name


N-70



z UlBeTrigTime6A1/UlBeTrigTime6B1/UlBeTrigTime6A2

/UlBeTrigTime6B2/UlBeTrigTime6D

Parameter name:

BE Trigger Time 6A1/6B1/6A2/6B2/6D

Recommended value:

640ms, 2560ms, 1280ms, 1280ms, 240ms

z UlBeTrigTime6A1/UlBeTrigTime6B1/UlBeTrigTime6A2/UlBeTrigTime6B2/UlBeTrigTime6D

Content: Duration when the measured value of BE keeps fulfilling the 6A1/6B1/6A2/6B2/6D measurement condition before the event 6A1/6B1/6A2/6B2/6D is triggered. The trigger time is used to prevent the sudden change of the measured value for being reported. The longer the trigger time is, the greater the effect of ignoring sudden changes is. Yet the response to changes of the measured value becomes slower.

Value range: D0, D10, D20, D40, D60, D80, D100, D120, D160, D200, D240, D320, D640, D1280, D2560, D5000

Physical value range: 0, 10, 20, 40, 60, 80, 100, 120, 160, 200, 240, 320, 640, 1280, 2560, 5000

Physical unit: ms

Set these parameters through SET QUALITYMEAS/ADD CELLQUALITYMEAS.

Course Name


N-71


Event 5A

z Event 5A:

z The UL BLER measurement may trigger event 5A. The RNC defines a sliding window of a

certain length through the parameter StaBlkNum5A. Each time the RNC receives a data

block, it compares the number of error blocks in the sliding window with the threshold of

event 5A specified by the parameter Thd5A. If the number of error blocks is above or

equal to the threshold of event 5A, event 5A is triggered. Then, the RNC can trigger again

event 5A only after the number of received error blocks reaches HangBlockNum5A, to

avoid excessive reporting of event 5A.

Course Name


N-72



z StaBlkNum5A

Parameter name: Statistic Block Number For 5A Event

Recommended value: 500

z Thd5A

Parameter name: Event 5A Threshold


z HangBlockNum5A

Parameter name: Interval Block Number


z StaBlkNum5A

Content: When a DCH is set up, the UE starts counting the number of faulty CRCs

within a specified sliding window. If the number of faulty CRCs exceeds the

specified threshold, event 5A is triggered. The length of the sliding window is

specified by this parameter.

Value range: 1~512


z Thd5A

Content: When a DCH is set up, the UE starts counting the number of faulty CRCs

within a specified sliding window. If the number of faulty CRCs exceeds this

parameter, event 5A is triggered.

Value range: 1~512


z HangBlockNum5A

Content: When event 5A is triggered, a pending timer is started, during which

event 5A will not be reported before the specified number is reached. This

parameter can control the frequency for reporting event 5A.

Value range: 1~512


z Set these parameters through ADD TYPRABQUALITYMEAS.

Course Name


N-73


Contents







Course Name


N-74


Downlink Stability Measurement Item

z DL stability measurement involves two measurement items: TCP and

RLC PDU retransmission rate

The TX power in the pilot field of the DPCCH is measured on the NodeB

side. When the TX power is above the threshold of event Ea, you can infer

that the radio link is unstable

Whether the RLC PDU retransmission rate needs to be measured can be

specified by the parameter SrncBeDlRlcQosSwitch. The RLC PDU

retransmission rate is reported by event A. When the RLC PDU

retransmission rate is above the threshold of event A, you can infer that

the radio link is unstable

z Link stability is measured through the TCP or RLC PDU retransmission rate in the DL. The

RNC performs rate decrease or rate increase for R99 BE services based on the link stability.

Course Name


N-75


Downlink Stability Measurement Event

z DL TX power in the pilot field of the DPCCH:

Event E (Ea/Eb): is used to check whether the DL power is

excessively high, and trigger a DL rate decrease

Event F (Fa/Fb): is used to check whether the DL power is

excessively low, and trigger a DL rate increase

z DL RLC PDU retransmission rate:

Event A: The PDU retransmission rate during the sliding window is

above the predefined threshold

Course Name


N-76


Event E

z Event E has two measurement thresholds, that is, E threshold 1 and E

threshold 2:

Event Ea means that the TX power is above E threshold 1

Event Eb means that the TX power is below E threshold 2

z For different services, there are different thresholds for event Ea/Eb.

The E threshold of event Ea/Eb is obtained from the relative threshold

and calculated according to the following formula:

E threshold = Maximum DL power Relative threshold + PO3

z Here:

Maximum DL power is specified by the RlMaxDlPwr parameter, that is, the

maximum DL RL TX power of DPDCHs.

Relative threshold is the relative threshold of event Ea or Eb, which is specified by

the ThdEa or ThdEb parameter respectively.

PO3 is the offset from the TX power of the DPCCH pilot field to the TX power of

DPDCHs.

Course Name


N-77


Event E (Cont.)

z Event E reporting mechanism:

PowerT1: measurement hysteresis time

Measurementthreshold 1

Measurementthreshold 2

T1

T1

T1

Ea Eb EaPeriodic reporting

Time

z As shown in the previous figure:

If the TX power of the pilot field of DPCCH is above threshold 1 for a period of

time specified by the DlBeTrigTimeE parameter, event Ea is triggered. Then, the

NodeB periodically reports the measurement results of TX power to the RNC.

The NodeB reporting period is specified by the ChoiceRptUnitForBeE,

TenMsecForBeE, or MinForBeE parameter.

If the TX power of the pilot field of DPCCH is below threshold 2 for a period of

time, event Eb is triggered. For BE services, this period is set to 640 ms. Then, the

NodeB stops reporting the measurement results of TX power.

Course Name


N-78



z RlMaxDlPwr

Parameter name: RL Max DL TX power

Recommended value: refer to Power Control course

z ThdEa/ThdEb

Parameter name: Event Ea/Eb Relative Threshold

Recommended value: None, none

z PO3

Parameter name: The power offsets of pilot fields of the DPCCH reference

to the power of DPDCHs

Recommended value: refer to Power Control course (3dB)

z ThdEa

Content: If DL code TX power is higher than the Ea absolute threshold, event Ea is

triggered. This event triggers DL QoS operation. This parameter specifies a relative

threshold.

Value range: 0~56

Physical value range: 0~28, step: 0.5

Physical unit: dB

z ThdEb

Content: If DL code TX power is lower than the Eb absolute threshold, event Eb is

triggered. When this event report is received, DL QoS operation is stopped. This

parameter specifies a relative threshold.

Value range: 0~56


Physical unit: dB

z Set these parameters through ADD TYPRABQUALITYMEAS.

Course Name


N-79



z DlBeTrigTimeE

Parameter name: BE Trigger Time Of Event E


z ChoiceRptUnitForBeE

Parameter name: BE Reporting Period Unit For Event E

Recommended value: TEN_MSEC

z TenMsecForBeE

Parameter name: BE Event E Reporting Period In 10ms


z DlBeTrigTimeE

Content: Duration from when the BE TX power is beyond the threshold Ea to when the

event Ea is triggered or from when the BE TX power is below the threshold Eb to when the

event Eb is triggered. This parameter is used to avoid faulty reporting due to instability of

power.

Value range: 1~6000


Physical unit: ms

z ChoiceRptUnitForBeE

Content: This parameter specifies the reporting period of the event E of the BE service. The

unit of the reporting period can be 10 ms or minute.

Value range: TEN_MSEC, MIN

Physical value range: TEN_MSEC, MIN

z TenMsecForBeE

Content: This parameter is valid when the corresponding parameter related to the reporting

period unit for the event E of BE service is set to TEN_MSEC. The DL code TX power is

reported periodically after the event Ea is reported. This parameter specifies the reporting

period. If the parameter is set to A, the reporting period is A x 10 ms.

Value range: 1~6000


Physical unit: ms

z Set these parameters through ADD CELLQUALITYMEAS/SET QUALITYMEAS.

Course Name


N-80


Event F

z Event F has two measurement thresholds, that is, F threshold 1 and F

threshold 2:

Event Fa means that the TX power is below F threshold 1

Event Fb means that the TX power is above F threshold 2

z The F threshold is related to the current rate and the target rate of rate

increase (triggered by event 4a). The F threshold is calculated according

to the following formula:

F threshold = Pmax p Pmargin Ea relative threshold + PO3

z Here:

Pmax is the maximum DL TX power corresponding to the target rate.

p is the power difference between current rate and target rate which is calculated in RNC through the parameters acquired by the simulation and field test

results.

Pmargin is the event F reporting power margin and determined by the parameter

BePwrMargin for a single service or by the parameter CombPwrMargin for

combined services.

Ea relative threshold is used to avoid repeated triggering of event Ea after a rate

increase.

PO3 is the offset from the TX power in the pilot field of the DPCCH to the TX

power of the DPDCHs.

z In RAN 11.0, the thresholds of events Fa and Fb are the same. The threshold of event F

cannot be above the threshold of event Ea. Otherwise, the threshold of event F is set to

the threshold of event Ea.

Course Name


N-81


Event F (Cont.)

z Event F reporting mechanism:

z As shown in the previous figure:

When the TX power of the pilot field of DPCCH is below threshold 1 for a period

of time specified by the DlBeTrigTimeF parameter, event Fa is triggered. Then, the

NodeB periodically reports the measurement results of TX power to the RNC.

The NodeB reporting period is specified by the ChoiceRptUnitForBeF,

TenMsecForBeF, or MinForBeF parameter.

When the TX power of the pilot field of the DPCCH is above threshold 2 for 640

ms, event Fb is triggered. Then, the NodeB stops reporting the measurement

results of TX power.

Course Name


N-82



z Pmax

Parameter name: the maximum DL TX power corresponding to the

target rate

Recommended value: refer to Power Control course

z BePwrMargin/CombPwrMargin

Parameter name: BE/Comb Event F Reporting Power Margin

Recommended value: 1dB, 2dB

z BePwrMargin

Content: The ralative power margin of single BE traffic, used to calculate the

triggering threshold of event F, can avoid the fluctuation of traffic rate in case the

power becomes restricted after rate is increased.

Value range: 0~100


Physical unit: dB

z CombPwrMargin

Content: The ralative power margin of combined traffics, used to calculate the

triggering threshold of event F, can avoid the fluctuation of traffic rate in case the

power becomes restricted after rate is increased.

Value range: 0~100


Physical unit: dB

z Set these parameters through ADD CELLDCCC/SET DCCC.

Course Name


N-83



z DlBeTrigTimeF

Parameter name: BE Trigger Time Of Event F


z ChoiceRptUnitForBeF

Parameter name: BE Reporting Period Unit For Event F

Recommended value: TEN_MSEC

z TenMsecForBeF

Parameter name: BE Event F Reporting Period In 10ms


z DlBeTrigTimeF

Content: Duration from when the BE TX power is below the threshold Fa to when the

event Fa is triggered or from when the BE TX power is beyond the threshold Fb to when

the event Fb is triggered. This parameter is used to avoid faulty reporting due to instability

of power.

Value range: 1~6000


Physical unit: ms

z ChoiceRptUnitForBeF

Content: This parameter specifies the reporting period of the event F of the BE service. The

unit of the reporting period can be 10 ms or minute.

Value range: TEN_MSEC, MIN

Physical value range: TEN_MSEC, MIN

z TenMsecForBeF

Content: This parameter is valid when the corresponding parameter related to the reporting

period unit for the event F of BE service is set to TEN_MSEC. The DL code TX power is

reported periodically after the event Fa is reported. This parameter specifies the reporting

period. If the parameter is set to A, the reporting period is A x 10 ms.

Value range: 1~6000


Physical unit: ms

z Set these parameters through ADD CELLQUALITYMEAS/SET QUALITYMEAS.

Course Name


N-84


Event A

z Event A reporting mechanism:

z The DL RLC PDU retransmission rate is calculated according to the ACK or NACK feedback

information.

z The RLC PDU retransmission rate is reported to layer 3 from layer 2.

z The procedure for measuring the RLC PDU retransmission rate is as follows:

Set up a sliding window for calculating the RLC PDU retransmission rate

periodically according to the period of monitoring the retransmission rate specified

by the parameter MoniterPrd.

Check whether the RLC PDU retransmission rate is above the threshold of event A

specified by the parameter EventAThred. If it is above the threshold for a period of

time, that is, MoniterPrd x TimeToTiggerA, event A is triggered and the RLC PDU

retransmission rate is reported.

In the period of time (MoniterPrd x PendingTimeA) after event A is reported, the

RLC PDU retransmission rate is not calculated any more. If a report on event Ea is

already received before a report on event A is received, the system may reduce the

DL rate.

Course Name


N-85



z SrncBeDlRlcQosSwitch

Parameter name: Srnc Parameter for BE Downlink RLC QOS


z MoniterPrd

Parameter name: re-TX monitor period


z SrncBeDlRlcQosSwitch

Content: When the parameter is set to YES, QoS control for DL BE services is based

on the TCP and RLC retransmission. When the parameter is set to NO, QoS control

for DL BE services is based on the TCP. In both situations, QoS control is not

performed across the Iur interface.



Set this parameter through SET QOSACT.

z MoniterPrd

Content: This parameter specifies a sampling period of retransmission ratio

monitoring after the RLC entity is established or reconfigured.

Value range: 40~60000


Physical unit: ms

Set this parameter through ADD TYPRABRLC.

Course Name


N-86



z EventAThred

Parameter name: Event A threshold

Recommended value: 160, namely 16%

z TimeToTiggerA

Parameter name: Event A time to trigger


z PendingTimeA

Parameter name: Event A pending time after trigger


z EventAThred

Content: This parameter specifies the threshold of event A, that is, the upper limit

of RLC retransmission ratio.

Value range: 0~1000

Physical value range: 0~100; step: 0.1

Physical unit: %

z TimeToTiggerA

Content: This parameter specifies the number of consecutive periods during which

the percentage of retransmitted PDUs is higher than the threshold of event A

before event A is triggered.

Value range: 1~100


z PendingTimeA

Content: This parameter specifies the number of pending periods after event A is

triggered. During the pending time, no event related to retransmission ratio is

reported.

Value range: 0~1000


z Set these parameters through ADD TYPRABRLC.

Course Name


N-87


Contents







Course Name


N-88


Rate Decrease in UL

z For rate decrease based on uplink stability, only the 3-Rates

decrease applies:

If the current rate is MBR, the rate is downsized to the value of

Uplink mid bit rate threshold

If the current rate is higher than Uplink full coverage bit rate and

lower than MBR, the rate is downsized to the value of Uplink full

coverage bit rate

z The Uplink mid bit rate threshold parameter is the same as that described in Rate

Adjustment Based on Traffic Volume.

Course Name


N-89


Rate Decrease in UL (Cont.)

z Rate decrease based on uplink stability in the case of 3-Rates

adjustment:

Course Name


N-90



z UlFullCvrRate

Parameter name: Uplink Full Coverage Bit Rate


z UlFullCvrRate

Content: Maximum UL rate when coverage of the entire cell is ensured under

certain load. For a BE service that has a low maximum rate, the DCCC algorithm is

not obviously effective yet it increases algorithm processing. Thus, the coverage-

based DCCC algorithm is applied to BE services whose maximum UL rate is greater

than the threshold.




Set this parameter through ADD CELLDCCC/SET DCCC.

Course Name


N-91


Rate Increase in UL

z Rate increase procedure based on uplink stability:

z Before rate increase, the RNC checks whether the current power is sufficient. If the power

is sufficient, rate increase is triggered by event 4a.

Course Name


N-92


Rate Increase in UL (Cont.)

z If the RNC receives a report on event 6B2 but does not receive

any report on event 6A2, the channel power is sufficient. In this

case, rate increase based on traffic volume can be triggered by

event 4a

z If the RNC receives a report on event 6A2, no rate increase

based on traffic volume can be triggered by event 4a

z If the RNC receives a report on event 6B1, rate decrease is

stopped and no rate increase can be triggered

Course Name


N-93


Contents







Course Name


N-94


Rate Decrease in DL

z For rate decrease based on downlink stability, only the 3-Rates

decrease applies:

If the current rate is MBR, the rate is downsized to the value of

Downlink mid bit rate threshold

If the current rate is higher than Downlink full coverage bit rate

and lower than MBR, the rate is downsized to the value of

Downlink full coverage bit rate

z The Downlink mid bit rate threshold parameter is the same as that described in Rate

Adjustment Based on Traffic Volume.

Course Name


N-95


Rate Decrease in DL (Cont.)

z Rate decrease based on downlink stability in the case of 3-Rates

adjustment:

Course Name


N-96



z DlFullCvrRate

Parameter name: Downlink Full Coverage Bit Rate


z DlFullCvrRate

Content: Maximum DL rate during network planning when coverage of the entire

cell is ensured. When the DL TCP is limited, the current rate is reduced to the full

coverage rate if the current rate is greater than the full coverage rate. For a BE

service that has a low maximum rate, the DCCC algorithm is not obviously effective

yet it increases algorithm processing. Thus, the DCCC algorithm is applied to BE

services whose maximum DL rate is greater than the threshold.




Set this parameter through ADD CELLDCCC/SET DCCC.

Course Name


N-97


Rate Increase in DL

z Rate increase procedure based on downlink stability:

z Before rate increase, the RNC checks whether the current power is sufficient. If the power

is sufficient, rate increase is triggered by event 4a.

Course Name


N-98


Rate Increase in DL (Cont.)

z If event Fa is reported, you can infer that the DL channel power

is sufficient. If event 4a is also reported, a rate increase can be

triggered

z If event Fb is reported, you can infer that the DL channel power

is insufficient. In this case, no rate increase can be triggered

Course Name


N-99


Contents







Course Name


N-100


Signaling Procedure

z Signaling procedure of rate decrease based on downlink

stability:

z For detailed information about the signaling procedure of rate increase, see Signaling

Procedure of Rate Adjustment Based on Traffic Volume.

Course Name


N-101


Contents

1. DCCC Overview






7. Always Online

z When the cell enters the basic congestion state, the RNC decreases the rate of BE services,

and the maximum target rate is the GBR for a BE RAB. When the cell exits from the basic

congestion state, the LDR function does not perform any task on the UEs in the cell. The

system decreases or increases service rates through the DCCC function.

Course Name


N-102


Contents


5.1 Rate Adjustment Based on Uplink Congestion

5.2 Rate Adjustment Based on Downlink Congestion

5.3 Rate Increase Failure and Penalty


Course Name


N-103


Rate Adjustment Based on Uplink Congestionz When LDR triggers BE service rate decrease, the selected RAB

rate is decreased to the target rate. The target rates for rate

adjustment are different for DCH RAB and HSUPA RAB:

If the selected RAB is a DCH RAB, the rate adjustment level can

only be 3_Rates:

If the current rate is equal to the MBR, it is decreased to the UL middle

rate threshold

If the current rate is higher than the GBR but lower than the MBR, it is

decreased to the GBR

z The UL mid bit rate threshold parameter is the same as that described in Rate Adjustment

Based on Traffic Volume.

Course Name


N-104


Rate Adjustment Based on Uplink Congestion (Cont.)

If the selected RAB is an HSUPA RAB, a rate is selected from the

HSUPA UL rate adjustment set as the target rate for rate decrease:

The target rate must be smaller than but the closest to the current rate.

Meanwhile it must be greater than or equal to the GBR

z The HSUPA UL rate adjustment set is the same as that described in Rate Adjustment Based

on Throughput.

Course Name


N-105


Rate Adjustment Based on Uplink Congestion (Cont.)

z The previous figure shows an example of UL BE rate decrease and increase in the case that

the RAB is a DCH RAB.

In this example, a rate decrease is triggered by UL basic congestion, and a rate

increase is triggered when basic congestion is relieved. In addition, the current UL

rate can be the initial rate, middle rate, or MBR.

When the current UL rate is the MBR, it is decreased to the middle rate if a UL

basic congestion report is received, and then decreased to the GBR if a second UL

basic congestion report is received.

Course Name


N-106


Contents


5.1 Rate Adjustment Based on Uplink Congestion

5.2 Rate Adjustment Based on Downlink Congestion

5.3 Rate Increase Failure and Penalty


Course Name


N-107


Rate Adjustment Based on Downlink Congestionz When a cell is in the basic congestion state in the downlink, the

rate of the selected RAB is decrease to the GBR if a BE rate

decrease is triggered. The rate decrease level can only be

3_Rates:

wcdma ran11 dccc algorithm and parameters

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