zte umts nb-amr rate control feature guide

NB-AMR Rate Control

Feature Guide

NB-AMR Rate Control

ZTE Confidential Proprietary 1

NB-AMR Rate Control

Version Date Author Reviewer Notes

V1.00 2014/02/8 Huang He Wang Juntao First edition

© 2014 ZTE Corporation. All rights reserved.

ZTE CONFIDENTIAL: This document contains proprietary information of ZTE and is not to be disclosed or used

without the prior written permission of ZTE.

Due to update and improvement of ZTE products and technologies, information in this document is subjected to

change without notice.

NB-AMR Rate Control


TABLE OF CONTENTS

1 Feature Attribute ............................................................................................... 6

2 Overview ............................................................................................................ 6

2.1 Feature Introduction ............................................................................................. 6

2.1.1 ZWF21-02-001 CS Conversational RAB for AMR Speech ................................... 8

2.1.2 ZWF21-04-005 AMR Rate Controlling.................................................................. 8

2.1.3 ZWF21-06-002 TrFO ........................................................................................... 9

2.2 License Control .................................................................................................. 10

2.3 Correlation With Other Features ........................................................................ 10

3 Technical Description ..................................................................................... 11

3.1 ZWF21-02-001 Conversational RAB for AMR .................................................... 11

3.1.1 NB-AMR Rate Selection..................................................................................... 11

3.1.2 Combination of the NB-AMR and PS Services ................................................... 12

3.1.3 NB-AMR Mobility ............................................................................................... 12

3.1.4 Directed Retry of the NB-AMR Service During RAB Assignment ....................... 12

3.1.5 AMR Rate Control After Relocation .................................................................... 13

3.1.6 Default Configuration of NB-AMR Rates: 12.2 kbps, 12.2/7.95/5.9/4.75 kbps,

and 7.95 kbps .................................................................................................... 13

3.1.7 RAB Modification of NB-AMR ............................................................................ 14

3.1.8 Signaling Flow of the AMR Service .................................................................... 14

3.2 ZWF21-04-005 AMR Rate Controlling................................................................ 17

3.2.1 Classification of AMR Dynamic Rate Adjustment ............................................... 17

3.2.2 AMR Dynamic Rate Adjustment Based on Radio Link Transmit Power .............. 18

3.2.3 Dynamic Adjustment Triggered by Load ............................................................ 24

3.2.4 Dynamic Adjustment Triggered by Resource Congestion .................................. 24

3.3 ZWF21-06-002 TrFO ......................................................................................... 25

3.3.1 OoBTC Out of Band Transcoder Control ............................................................ 26

3.3.2 Iu UP Initialization .............................................................................................. 27

3.3.3 Iu UP Rate Control ............................................................................................. 28

4 Parameters ....................................................................................................... 30

4.1 ZWF21-02-001 Conversational RAB for AMR .................................................... 30

4.2 ZWF21-04-005 AMR Rate Controlling................................................................ 33

4.2.1 Uplink Rate Adjustment Based on the UE Transmitted Power ........................... 33

4.2.2 Downlink Rate Adjustment Based on the Dedicated Measurement of Node B

Transmitted Power ............................................................................................. 36

4.2.3 Dynamic Adjustment Triggered by Load and Resource Congestion ................... 43

4.3 ZWF21-06-002 TrFO ......................................................................................... 44

NB-AMR Rate Control


5 Related Counters and Alarms ........................................................................ 45

5.1 Related Counters ............................................................................................... 45

5.2 Related Alarms .................................................................................................. 49

6 Engineering Guide .......................................................................................... 49

6.1 Application Scenario .......................................................................................... 49

6.1.1 ZWF21-02-001 Conversational RAB for AMR .................................................... 49

6.1.2 ZWF21-04-005 AMR Rate Controlling................................................................ 49

6.1.3 ZWF21-06-002 TrFO ......................................................................................... 49

6.2 Feature Activation Procedure ............................................................................. 50



6.2.3 ZWF21-06-002 TrFO ......................................................................................... 57

6.3 Feature Validation Procedure ............................................................................ 58



6.3.3 ZWF21-06-002 TrFO ......................................................................................... 59

6.4 Feature Deactivation Procedure ......................................................................... 59



6.4.3 ZWF21-06-002 TrFO ......................................................................................... 59

6.5 Impact on the Network ....................................................................................... 59



6.5.3 ZWF21-06-002 TrFO ......................................................................................... 60

7 Abbreviations .................................................................................................. 61

8 Reference Documents ..................................................................................... 61

NB-AMR Rate Control


FIGURES

Figure 3-1 Signaling Flow of the AMR Service ...................................................................14

Figure 3-2 Flow of OoBTC Out of Band Transcoder Control ..............................................27

Figure 3-3 Iu UP Initialization .............................................................................................28

Figure 3-4 Flow of Iu UP Rate Control ...............................................................................29

Figure 6-1 Parameter Configuration Interface 1 .................................................................50









Figure 6-10 Parameter Configuration Interface 10 .............................................................56



TABLES

Table 2-1 NB-AMR Rate Classification ............................................................................... 7

Table 2-2 License Control List ...........................................................................................10

Table 4-1 Parameter Description .......................................................................................30





NB-AMR Rate Control


Table 5-1 Counters ............................................................................................................45

Table 6-1 Feature Validation Procedure.............................................................................58

Table 6-2 RNC Parameter .................................................................................................59

NB-AMR Rate Control


1 Feature Attribute

BSC/RNC version: [ZXUR 9000 UMTS V4.13.10.15/V3.13.10.15]

BTS/Node B version: [ZXSDR V4.13.10.20]

Attribute: [Optional]

Involved NEs:

NE Name Related or Not Special Requirements

MS/UE √ UE should support NB-AMR feature.

BTS/Node B √ None.

BSC/RNC √ RNC should support NB-AMR feature.

iTC - None.

MSC - None.

MGW - None.

SGSN - None.

GGSN - None.

HLR √ The UE subscribes to the NB-AMR service.

“√”: involved

“-”: not involved

2 Overview

2.1 Feature Introduction

The Adaptive Multi-Rate (AMR) codec provides a high-quality voice service with flexible

multi-rate to reach a balance between voice quality and system capability (network load).

Currently, 3GPP uses two formats: Narrowband Adaptive Multi-Rate (NB-AMR) and

Wideband Adaptive Multi-Rate (WB-AMR), and both of them use the same frame length

of 20 ms. For NB-AMR, the voice channel bandwidth is limited to 3.7 kHz and the

sampling frequency is 8,000 Hz. For WB-AMR, the voice channel bandwidth is 7 kHz and

the sampling frequency is 16,000 Hz. The voice quality of WB-AMR is higher than that of

NB-AMR Rate Control


NB-AMR. If WB-AMR is required, the UE must support it, and whether a UE supports

WB-AMR is indicated in the SETUP uplink direct transfer message from the UE.

AMR Control (AMRC) indicates adjusting AMR between different rates in WCDMA

systems. Through AMRC, voice rate can be reduced to improve voice quality and reduce

system load. AMRC can be used in the following scenarios:

The load at the downlink air interface exceeds the threshold.

The load at the uplink air interface exceeds the threshold.

Uplink coverage is limited and the AMR rate can be reduced to widen uplink

coverage.

When system load is light, AMRC can be used to increase the AMR rate. In this way,

QoS is greatly improved.

The NB-AMR service has three service RAB sub-flows and can provide eight voice rates

and the Silence Descriptor (Comfort Noise Frame). The NB-AMR codec modes related to

UMTS_AMR are shown in the following table.

Table 2-1 NB-AMR Rate Classification

AMR

Codec Mode

Total Number

of Bits

Sub-flow 1 Sub-flow 2 Sub-flow 3

AMR 4.75 kbps 95 42 53 0

AMR 5.15 kbps 103 49 54 0

AMR 5.9 kbps 118 55 63 0

AMR 6.7 kbps

(PDC EFR) 134 58 76 0

AMR 7.4 kbps

(TDMA EFR) 148 61 87 0

AMR 7.95 kbps 159 75 84 0

AMR 10.2 kbps 204 65 99 40

AMR 12.2 kbps

(GSM EFR) 244 81 103 60

AMR SID 39 39 0 0

NB-AMR Rate Control


AMR

Codec Mode

Total Number

of Bits

Sub-flow 1 Sub-flow 2 Sub-flow 3

(Comfort Noise

Frame)

NB-AMR voice coding is divided into three sub-flows in accordance with the importance

of information and error tolerance in voice coding. Each sub-flow requires its own QoS

assurance. Sub-flow 1 is the most important. Sub-flow 2 comes next. Sub-flow 3 is the

least important. Sub-flow 1 requires better channel coding at the air interface to

guarantee accuracy. The "no data" rate is coded when there is no voice (mute). SID is

used to indicate that voice is not activated currently.

2.1.1 ZWF21-02-001 CS Conversational RAB for AMR Speech

ZTE's equipment supports all the eight NB-AMR rates: 12.2 kbps, 10.2 kbps, 7.95 kbps,

7.4 kbps, 6.7 kbps, 5.9 kbps, 5.15 kbps, and 4.75 kbps, and also supports DTX and SID.

The RAB parameters of ZTE's RAN, used to bear AMR services, are configured in

accordance with 3GPP TS 34.108.

2.1.2 ZWF21-04-005 AMR Rate Controlling

In a WCDMA system, the radio conditions between a UE and the base station always

change. When the UE is far from the base station or the radio conditions are poor, the

base station or the UE must have greater transmit power under the closed-loop power

control to guarantee the QoS of the AMR service. The increase of the power may result

in further deterioration of radio conditions. As a result, system capacity decreases and

the QoS requirements of the service cannot be met even when the power is increased to

the maximum value.

ZTE's RNC can monitor the uplink transmit power contained in the UE internal

measurement report or the downlink transmit power contained in the NodeB-dedicated

measurement report. When the uplink or downlink transmit power rises to a threshold,

the RNC automatically adjusts the UE's NB-AMR rate to reduce the power required for

the service. This indicates that voice quality is reduced to retain calls. When the radio

conditions between a UE and the base station are good and the transmit power of the

NB-AMR Rate Control


base station or the UE decreases to a threshold, the AMR rate can be increased to

provide the UE with higher voice quality when the system is neither overloaded nor

congested.

In addition, when the downlink and uplink load of a cell is high in accordance with its

downlink transmit power and uplink interference, ZTE's RNC can lighten the cell load by

reducing the NB-AMR rate of some UEs with low priorities so that more UEs can be

supported.

The RNC can only adjust the NB-AMR rates belonging to the NB-AMR code set

configured by the CN for UEs during call establishment. The voice quality when low-rate

AMR coding is used is lower than that when high-rate AMR coding is used but the

capacity (number of UEs) is higher and the coverage is wider. The simulation result

shows that when the lowest NB-AMR (4.75 kbps) is used instead of the highest NB-AMR

(12.2 kbps), the coverage radius gain is about 30% and the UEs supported by the cell

may increase by 100%.

2.1.3 ZWF21-06-002 TrFO

WCDMA systems use AMR compressed voice coding. In the R99 phase, a TDM bearer

is used between CS core network devices, and 64 kbit/s PCM coding must be used for

voice. Voice Transcoder (TC) is an important function of the R99 MSC, converting the

AMR voice codes of mobile terminals into PCM codes and transmits them over the

network. The calls between mobile users require two voice code conversions

(AMR-PCM-AMR). Frequent encoding and decoding reduce voice quality.

Therefore, 3GPP introduced Tandem Free Operation (TFO) and Transcoder Free

Operation (TrFO) in the R4 protocol to avoid voice encoding and decoding. With these

two technologies, the transmission network bandwidth between core networks can be

saved. The differences between the technologies are as follows: TFO needs TC

resources. After a call is established, a direct connection is established between the TCs

of the calling and called MSCs through in-band signaling negotiation to bypass encoding

and decoding. TrFO does not need TC resources. This indicates that Out of Band

Transcoder Control (OoBTC) is used during call establishment to perform consistent

voice encoding and decoding negotiation between the UE and the network.

NB-AMR Rate Control


The TFO technology is used on core network devices without the RAN. The TrFO

technology requires that the RAN should support out-band voice encoding negotiation

and the processing related to the user plane.

ZTE's RAN supports the TrFO function and complies with 3GPP TS 23.153 and TS

25.415.

2.2 License Control

Table 2-2 License Control List

Feature ID Feature Name License

Control Item

Configured

NE Unit

ZWF21-02-001 CS Conversational

RAB for AMR Speech N/A N/A N/A

ZWF21-04-005 AMR Rate Controlling AMR Rate

Controlling RNC RNC

ZWF21-06-002 TrFO N/A N/A N/A

2.3 Correlation With Other Features

1. Required Features

None.

2. Mutually Exclusive Features

None.

3. Affected Features

None.

NB-AMR Rate Control


3 Technical Description

3.1 ZWF21-02-001 Conversational RAB for AMR

3.1.1 NB-AMR Rate Selection

The 3GPP specifications define eight voice rates and one SID for UMTS NB-AMR, and

the highest voice rate supported is 12.2 kbps.

3.1.1.1 RAB Assignment

ZTE's RNC determines the NB-AMR rate set according to the value of UP Mode

Versions in the RAB ASSIGNMENT REQUEST message.

If the value of UP Mode Versions in the RAB ASSIGNMENT REQUEST message is 1,

the available rates for the service are determined by the intersection of the configured

rate set on the RNC and the received MBR and GBR from the CN. The related

parameters are ULogicalRnc.amrNbMode0UseTag (4.75 kbps),

ULogicalRnc.amrNbMode1UseTag (5.15 kbps), ULogicalRnc.amrNbMode2UseTag (5.9

kbps), ULogicalRnc.amrNbMode3UseTag (6.7 kbps),

ULogicalRnc.amrNbMode4UseTag (7.4 kbps), ULogicalRnc.amrNbMode5UseTag (7.95

kbps), ULogicalRnc.amrNbMode6UseTag (10.2 kbps), and

ULogicalRnc.amrNbMode7UseTag (12.2 kbps), which indicate whether the rates are

supported on the RNC.

If the value of UP Mode Versions in the RAB ASSIGNMENT REQUEST message is 2,

the RNC supports all the NB-AMR rates assigned by the CN.

If the value of UP Mode Versions in the RAB ASSIGNMENT REQUEST message is 3

and ULogicalRnc.IntraRatV1V2AmrCut is set to cut, the processing on the RNC side is

the same as that when UP Mode Versions is set to 1. If the value of UP Mode Versions

in the RAB ASSIGNMENT REQUEST message is 3 and

ULogicalRnc.IntraRatV1V2AmrCut is set to not cut, the processing on the RNC side is

the same as that when UP Mode Versions is set to 2.

NB-AMR Rate Control


3.1.1.2 GBR Reservation for the AMR Service

ZTE's RNC can be used to determine whether the GBR should be contained in the

NB-AMR rate set.

When the value of UP Mode Versions in the RAB ASSIGNMENT REQUEST message

is 1 or the value of UP Mode Versions is 3 and ULogicalRnc.IntraRatV1V2AmrCut is set

to cut, the NB-AMR rates configured by the RNC may be different from the NB-AMR rate

set assigned by the CN in the RAB ASSIGNMENT REQUEST message. To avoid the

problem that the RNC does not support the GBR in the RAB ASSIGNMENT REQUEST

message, you can set ULogicalRnc.amrGbrResInd to determine that the GBR in the

RAB ASSIGNMENT REQUEST message must be contained in the supported rate set.

If ULogicalRnc.amrGbrResInd is set to 1: True, the actual NB-AMR rate set contains the

intersection of the above two AMR rate sets and the GBR in the RAB ASSIGNMENT

REQUEST message.

If ULogicalRnc.amrGbrResInd is set to 0: False, the actual NB-AMR rate set is the

intersection of the above two AMR rate sets. The GBR used on the RNC is the lowest

rate among the rates (in the NB-AMR rate set) larger than or equal to the GBR in the

RAB ASSIGNMENT REQUEST message.

3.1.2 Combination of the NB-AMR and PS Services

ZTE's RNC supports the NB-AMR service and the combination of the NB-AMR and PS

services.

3.1.3 NB-AMR Mobility

ZTE's RNC supports the soft handover, hard handover, and relocation of the NB-AMR

service, and the handover between the 2G and 3G systems.

3.1.4 Directed Retry of the NB-AMR Service During RAB Assignment

The RNC supports the directed retry of the NB-AMR service during RAB assignment. If

the load of the cell where the UE resides is too heavy during RAB assignment, the UE is

NB-AMR Rate Control


directed to a 2G system. For details, refer to the ZTE UMTS Directed Retry to GSM

Feature Guide.

3.1.5 AMR Rate Control After Relocation

Due to UE compatibility problems, some UEs become mute if the NB-AMR service rate is

changed after inter-RNC soft handover or hard handover relocation. Therefore,

URncInfo.IntraRlocAmrRtCtrl is used to control whether the NB-AMR service rate can be

changed after the relocation.

If URncInfo.IntraRlocAmrRtCtrl is set to 0: AMR Rate Changing is Allowed after

Relocation or the NB-AMR service rate before relocation is not contained in the

Relocation Request message, or the Iu UP version is V2, the NB-AMR service rate can

be changed after inter-RNC relocation. The methods that determine the NB-AMR service

rate set and the actual NB-AMR service rate after relocation are described in other

sections of this manual.

If URncInfo.IntraRlocAmrRtCtrl is set to 1: AMR Rate Changing is Not Allowed after

Relocation, the NB-AMR service rate before relocation is contained in the Relocation

Request message, and the Iu UP version is V1, the NB-AMR service rate cannot be

changed after inter-RNC relocation. The NB-AMR service rate set only contains the

NB-AMR service rates smaller than or equal to the actual NB-AMR service rate before

relocation, and the actual NB-AMR service rates before and after relocation are the

same.

3.1.6 Default Configuration of NB-AMR Rates: 12.2 kbps, 12.2/7.95/5.9/4.75

kbps, and 7.95 kbps

The RNC supports the default configuration of the following NB-AMR rates: 12.2 kbps,

combinations of 12.2, 7.95, 5.9, and 4.75 kbps, and 7.95 kbps for the handover from the

2G system to the 3G system. The RNC determines the default configuration according to

the MBR and GBR in the Relocation Request message received from the CN,

establishes the bearer according to the default configuration, sets the default cells in the

HANDOVER TO UTRAN COMMAND message, and sends this message to the UE

through the 2G network.

NB-AMR Rate Control


3.1.7 RAB Modification of NB-AMR

The RNC supports RAB modification for the NB-AMR service that the CN initiates by

sending the RAB ASSIGNMENT REQUEST message. The CN initiates RAB

modification for the NB-AMR service when the TFO or TrFO conditions are satisfied after

handover, call forwarding, and intelligent services.

3.1.8 Signaling Flow of the AMR Service

The following figure shows the establishment flow of the NB-AMR service in synchronous

mode.

Figure 3-1 Signaling Flow of the AMR Service

6. Downlink Synchronisation

7. Uplink Synchronisation

UE Node B

Serving RNS

Serving

RNC

CN

RRC RRC

10. DCCH : Radio Bearer Setup Complete

NBAP NBAP 4. Radio Link Reconfiguration Ready

DCH-FP

NBAP NBAP 8. Radio Link Reconfiguration Commit

RRC RRC

9. DCCH : Radio Bearer Setup

Apply new transport format set

Select L1, L2 and Iu Data

Transport Bearer parameters

RANAP RANAP

11. RAB Assignment

Response

5. ALCAP Iub Data Transport Bearer Setup

2. ALCAP Iu Data

Transport Bearer Setup

Not required towards PS

domain

RANAP RANAP

1. RAB Assignment

Request

[Establishment]

NBAP NBAP 3. Radio Link Reconfiguration Prepare

[DCH Addition]

DCH-FP DCH-FP

DCH-FP

NB-AMR Rate Control


1 The CN initiates the establishment of a radio access bearer by sending the RANAP

message Radio Access Bearer Assignment Request. The important parameters

for the CS service are as follows:

(Optional) NAS Synchronization Indicator indicates the speech codec type

selected by the CN. The RNC passes this cell to the UE. The codec types related to

UMTS AMR are displayed in the following table. For details, refer to 3GPP 26.103.

If the UE does not receive this cell during the establishment of a voice call or the

inter-system handover of a voice call to the UTRAN, the UMTS_AMR_2 speech

codec is used by default. UMTS_AMR_2 is compatible with GSM FR AMR.

Bit 8…Bit 1

CoID (Codec

Identification)

Codec_Type Name

0000.0101 UMTS Adaptive Multi-Rate UMTS AMR

0000.0110 UMTS Adaptive Multi-Rate

2

UMTS AMR 2

0000.1010 UMTS Adaptive Multi-Rate

Wide Band

UMTS WB-AMR

RAB parameters (including QoS) include the following parameters:

Traffic Class, value: conversational

MBR (Maximum Bit Rate), unit: bit/s

GBR (Guaranteed Bit Rate), unit: bit/s

Delivery Order, value: provide in-sequence SDU delivery (for the AMR

service)

SDU parameters, describing the three RAB sub-flows of the AMR service

Source Statistics Descriptor, value: speech (for the AMR service)

Allocation/Retention Priority

User plane Information parameters:

NB-AMR Rate Control


User Plane Mode, value: support mode for predefined SDU sizes (for the

AMR service).

UP Mode Versions indicates the user plane version supported by the CN,

containing 16 bits. Each bit indicates a user plane version, and a maximum of

16 user plane versions can be displayed. The highest bit indicates version 16

and the lowest bit indicates version 1. For support mode for predefined SDU

sizes, version 1 and version 2 are defined in the current version (release 99).

Transport layer information parameters include Transport Address and Iu

Transport Association.

2 The SRNC initiates the establishment of the Iu data transport bearer by sending the

ALCAP message. This message contains the AAL2 binding identity, which is used

to bind the Iu data transport bearer to the radio access bearer.

3 The SRNC requests its NodeB to prepare the establishment of DCH to support the

radio access bearer (Radio Link Reconfiguration Prepare). The parameters include

Transport Format Set, Transport Format Combination Set, and power control

information parameters.

4 The NodeB allocates resources and notifies the SRNC that the radio link

reconfiguration is ready (Radio Link Reconfiguration Ready). The parameters

include the transport layer addressing information (AAL2 address and AAL2 Binding

ID) for the Iub data transport bearer.

5 The SRNC initiates the establishment of the Iub data transport bearer by sending

the ALCAP message. This message contains the AAL2 binding identity, which is

used to bind the Iub data transport bearer to DCH.

6 The NodeB and the SRNC use the Iub or Iur data transport bearer to exchange the

DCH frame protocol message Downlink Synchronization to synchronize the Iub or

Iur interface.

7 The NodeB and the SRNC use the Iub or Iur data transport bearer to exchange the

DCH frame protocol message Uplink Synchronization to synchronize the Iub or Iur

interface.

NB-AMR Rate Control


8 The NBAP message Radio Link Reconfiguration Commit is sent from the SRNC

to the NodeB.

9 The RRC message Radio Bearer Setup is sent from the SRNC to the UE. The

parameters include Transport Format Set and Transport Format Combination

Set.

10 The UE sends the RRC message Radio Access Bearer Setup Complete to the

SRNC.

11 The SRNC sends the RANAP message Radio Access Bearer Assignment

Response to the CN

3.2 ZWF21-04-005 AMR Rate Controlling

3.2.1 Classification of AMR Dynamic Rate Adjustment

The RNC supports dynamic rate adjustment for the AMR service triggered by link-level

transmit power, resource congestion, and load control during calls. If the rate adjustment

threshold is reached, the uplink rate is controlled by the RNC through the TFC control

command, and the downlink rate is controlled by the RNC through the Iu UP reverse rate

control frame.

The NB-AMR dynamic rate adjustment is controlled by the ULogicalRnc.amrRncAdjust

parameter.

There are three types of AMR dynamic rate adjustment depending on the trigger

mechanisms:

NB-AMR dynamic rate adjustment based on link-level transmit power

Due to inner-loop power control, the uplink/downlink link-level transmit power vary with

the change of the radio conditions of the transmitting antennas of the UE and the NodeB.

When the radio conditions degrade, the RNC should reduce the NB-AMR rate to reduce

transmit power to avoid heavy uplink/downlink load of the cell. When the transmit power

of the NB-AMR link is low and the system load is light, the RNC can increase the

NB-AMR Rate Control


NB-AMR rate to maximize the utilization of system resources to provide users with better

voice quality.

NB-AMR rate adjustment triggered when uplink/downlink resources are congested

or the cell is overloaded

Reduce the rate of the uplink/downlink AMR service to reduce uplink/downlink resource

congestion.

Initial NB-AMR rate adjustment triggered when the cell is overloaded or the UE is a

poorly covered area

When the cell is overloaded or the UE is in a poorly covered area, the initial and the

highest AMR service rates should be reduced to lighten cell load and improve link

performance. For details, refer to the ZTE UMTS Adaptive Radio Bearer Feature Guide.

For these three trigger mechanisms, ZTE's RNC can only adjust the rate of the NB-AMR

service in the range of NB-AMR rates.

3.2.2 AMR Dynamic Rate Adjustment Based on Radio Link Transmit

Power

3.2.2.1 Uplink Rate Adjustment Based on UE Transmit Power

3.2.2.1.1 Measurement Quantity

The AMR rate adjustment in uplink is base on the UE internal measurement reports of

UE TxP (Transmitted Power). There are two kinds of event, Event 6a and Event 6b.

UAmrEvtTPUeInt.meaEvtId defines the UE internal event identity.

Event 6a: when the UE TxP measurement value is greater than a certain absolute

threshold and this condition lasts for the duration TriggerTime6A, the Event 6a is

reported by the UE. TriggerTime6A is defined by the parameter

UAmrEvtTPUeInt.trigTime[0].

Event 6b: when the UE TxP measurement value is smaller than a certain absolute

threshold and this condition lasts for the duration TriggerTime6B, the Event 6b is

NB-AMR Rate Control


reported by the UE. TriggerTime6B is defined by the parameter

UAmrEvtTPUeInt.trigTime[1].

The parameters for 6a and 6b can be configured at cell level. The number of internal

measurement events is configured by UAmrEvtTPUeInt.measEvtNum. It can be set to

“2”, for Event 6a and 6b. To facilitate the description, it is assumed that 0 represents 6a

and 1 represents 6b.

The UE Txp threshold of Event 6a/6b (UAmrEvtTPUeInt.txPowerThres) is a delta value

relative to maximum UE TX power which is determined by the formula “min (UE

maximum transmitted power determined by UE power class,

USrvDivPc.maxUlDpchPwr)”. USrvDivPc.maxUlDpchPwr is the maximum transmitted

power determined by the sub-service type of NB-AMR service.. And the UE maximum

transmitted power determined by the UE power class is listed as follows.

Power Class 3 4

maximum output power of

the UE (dBm)

+24 +21

The absolute UE TxP thresholds of Event 6a and 6b are as follows.

AMR_6a = maximum UE TX power + UAmrEvtTPUeInt.txPowerThres[0]

AMR_6b = maximum UE TX power + UAmrEvtTPUeInt.txPowerThres[1]

The correspondence between other parameters that need to be filled in UE internal

measurement control message and OMC configuration is described as follows. Firstly

“Used UUeIntMeasProfile” (UUtranCellFDD.refUUeIntMeasProfile) of the cell is obtained

from the management object “UTRAN Cell Object”(UUtranCellFDD). Secondly. from the

value of UUtranCellFDD.refUUeIntMeasProfile, the corresponding profile

ID(UueIntMeasProfile.profileId) of the UUtranCellFDD’s child management object “UE

Internal Measurement Profile Object” (UueIntMeasProfile), which is used by the cell, is

obtained. And thirdly, from the child management object UueIntMeasProfile, which is

identified by the UueIntMeasProfile.profileId, the corresponding UE Internal

Measurement parameter based on the measurement target is obtained.

UE Internal Measurement Configuration Index UAmrEvtTPUeInt.ueIntMCfgNo

Measurement report transmission mode UAmrEvtTPUeInt.measRptTrMod

NB-AMR Rate Control


UE Internal Measurement Configuration Index UAmrEvtTPUeInt.ueIntMCfgNo

Filter coefficient UAmrEvtTPUeInt.filterCoeff

Maximum Event Number of UE Internal

Measurement UAmrEvtTPUeInt.measEvtNum

UE Internal Measurement Event Identity UAmrEvtTPUeInt.meaEvtId

Time to Trigger UAmrEvtTPUeInt.trigTime

UE Transmitted Power Threshold UAmrEvtTPUeInt.txPowerThres

3.2.2.1.2 Rate Control Principles

If ULogicalRnc.amrRncAdjust is On and the number of uplink NB-AMR rates is larger

than 1, UE TxP measurement is enabled. Otherwise, UE TxP measurement is disabled.

The operating principles are as follows:

If the uplink transmit power reported by the UE exceeds the threshold (AMR_6a)

and the current uplink NB-AMR rate is not the lowest rate, the NB-AMR rate level

must be reduced by one. After the uplink NB-AMR rate level is reduced, a new

measurement control command is sent to the UE.

If the uplink transmit power reported by the UE is lower than the threshold

(AMR_6b), the current uplink NB-AMR rate is not the highest rate, and the system is

neither overloaded nor congested with uplink load, the NB-AMR rate level must be

increased by one. After the uplink NB-AMR rate level is increased, a new

measurement control command is sent to the UE.

For TrFO connection mode, the following operations must be also performed:

If the target NB-AMR rate is smaller than or equal to the highest uplink rate of the Iu

interface, the rate can be increased. Otherwise, the uplink rate cannot be increased.

When the RNC receives the rate control command from the CN, the highest rate is the

uplink target rate required by the CN. The RNC determines whether the target rate can

be adjusted by the current RNC according to cell uplink load and the UE transmit power

measurement report. If the target rate can be adjusted by the RNC, the RNC returns the

rate control response command containing the rate to the peer end. At the same time,

the RNC sends the TFC control command to the UE, requiring that the UE uplink rate

NB-AMR Rate Control


should be adjusted to the target rate. If the target rate cannot be adjusted by the RNC,

the RNC sends a Rate Control NACK message to the CN.

3.2.2.2 Downlink Rate Adjustment Based on the Dedicated Measurement of Node

B Transmit Power

3.2.2.2.1 Measurement Quantity

The downlink NB-AMR rate adjustment is based on the D-TCP (Dedicated Transmitted

Code Power) measurement report from Node B. It indicates that the downlink transmitted

power for the UE (the TCP on the given carrier, given scramble, and given channelization

code) is measured by the Node B. The Node B dedicated TCP measurement for the

NB-AMR rate control is reported periodically and the period is configured by

UNbDedMeas.RptPrd. Whether the criterion for Event A or Event B is met is determined

by the RNC. Event A and Event B are defined as follows:

Event A: when the Node B D-TCP measurement value is greater than a specific

absolute threshold AMR_A for the duration TriggertimeA, the Event A is triggered.

When the criterion of Event A is met, the downlink transmitted power for a certain

UE is considered to be in a high power status, and the downlink rate could be

decreased.

Event B: when the Node B D-TCP measurement value is smaller than a specific

absolute threshold AMR_B for the duration TriggertimeB , the Event B is triggered.

When the criterion of Event B is satisfied, the downlink transmitted power for a

certain UE is considered to be in a low power status, and the downlink rate could be

increased.

The definition of AMR_A and AMR_B are as followed.

AMR_A = USrvDivPc.maxDlDpchPwr + evtAbTcpThrd_A

AMR_B = USrvDivPc.maxDlDpchPwr + evtAbTcpThrd_B

Where

NB-AMR Rate Control


- USrvDivPc.maxDlDpchPwr is the maximum downlink DPCH transmitted power for

NB-AMR service. The detailed description refers to ZTE UMTS Power Control

Feature Guide.

- evtAbTcpThrd_A is defined by the parameter UNbDedMeas.evtAbTcpThrd[0]

indexed by UNbDedMeas.nbDMCfgNote =7

- evtAbTcpThrd_B is defined by the parameter UNbDedMeas.evtAbTcpThrd[0]

indexed by UNbDedMeas.nbDMCfgNote =8

The correspondence between other parameters that need to be filled in dedicated

measurement initiation request message and OMC configuration is described as follows.

Firstly the Profile Id for the NodeB dedicated measurement

(UNbDedMeasProfile.profileId) of the cell is obtained from the management object

“UNbDedMeasProfile”. Secondly, from the value of UNbDedMeasProfile.profileId, the

corresponding child management object “NodeB Dedicated Measurement

Configuration”(UnbDedMeas) is found. Thirdly, The corresponding

UNbDedMeas.nbDMCfgNote could be obtained according to the measurement purpose.

And finally the parameters for the measurment are obtained according to the value of

UNbDedMeas.nbDMCfgNote.

Dedicated Measurement Type UNbDedMeas.dedMeasType

Measurement Filter Coefficient UNbDedMeas.measFilterCoeff

Report Characteristics UNbDedMeas.rptType

Measurement Threshold of Event A/B for

Transmitted Code Power UNbDedMeas.evtAbTcpThrd

Measurement Change Time/Measurement

Hysteresis Time UNbDedMeas.evtAbcdefTime

Choice Report Periodicity Scale UNbDedMeas.rptPrdUnit

Report Period UNbDedMeas.rptPrd

DPCH Maximum DL Power USrvDivPc.maxDlDpchPwr

Event A Counter Threshold for PS on DL

DCH or DL AMR Decreasing Rate Based on

D-TCP UDrbc.dtcpEaThd

Event B Counter Threshold for Restriction PS

Increasing Rate on DL DCH or Triggering DL

AMR Increasing Rate Based on D-TCP UDrbc.dtcpEbThd

mailto:#@UNbDedMeas.nbDMCfgNote@

mailto:#@UNbDedMeas.nbDMCfgNote@

NB-AMR Rate Control


3.2.2.2.2 Rate Control Principles

If ULogicalRnc.amrRncAdjust is On and the number of downlink NB-AMR rates is larger

than 1, DTCP measurement is enabled. Otherwise, NodeB-dedicated TCP measurement

is disabled.

The basic principles are as follows:

When the special downlink transmit power reported by the NodeB exceeds the

threshold (AMR_A) UDrbc.dtcpEaThd times consecutively and the current downlink

NB-AMR rate is not the lowest rate, the downlink NB-AMR rate level must be

reduced by one.

When the special downlink transmit power reported by the NodeB is lower than the

threshold (AMR_B) UDrbc.dtcpEbThd times consecutively, the current downlink

NB-AMR rate is not the highest rate, and the system is neither overloaded nor

congested with downlink load, the downlink NB-AMR rate level must be increased

by one.

For TrFO connection mode, the downlink rate depends on the downlink rate of the Iu

interface. In a mobile-to-mobile call, the downlink rate depends on the uplink rate of the

peer end. Therefore, the downlink NB-AMR rate adjustment algorithm is changed as

follows in comparison with the non-TrFO connection mode:

When the local end needs to adjust the downlink NB-AMR rate, the RNC sends the

adjusted target rate through the rate control command to the CN, and the CN sends

this rate through the rate control command to the peer RNC. The returned rate

control response command contains the highest uplink rate supported by the peer

end. The peer UE sends data at the smaller rate between the highest uplink rate

supported by the peer end and the target rate required by the local end. In this way,

the downlink rate of the local end is adjusted.

When the uplink rate of the peer end is reduced, the downlink rate of the local end is

reduced accordingly.

When the uplink rate of the peer end is increased, the downlink rate of the local end

is increased accordingly, resulting in the change of the downlink load of the cell and

the downlink D-TCP of the link. The RNC should determine whether to reduce the

NB-AMR Rate Control


increasing downlink rate according to the downlink load of the cell and the downlink

D-TCP measurement report. If the downlink rate must be reduced, the RNC sends

the rate control command to the CN, containing the highest rate supported by the

local end. In this way, the downlink rate of the Iu interface is controlled.

3.2.3 Dynamic Adjustment Triggered by Load

In case of uplink or downlink overload in a cell, the RNC must reduce the rates of AMR

services in accordance with their priorities.

When the cell is not overloaded and the NB-AMR services whose rates are reduced

meet the conditions described in section 3.3.2 Iu UP Initialization, the RNC increases

their rates level by level.

When the switch of forbidding AMR downgrade is turned on (URncInfo.loadForAmrSwit

is 1: forbidden), the AMR downgrade triggered by load control is not performed. If

URncInfo.loadForAmrSwit is 0, the original load control downgrade policy is recovered.

For details, refer to the ZTE UMTS Overload Control Feature Guide.

3.2.4 Dynamic Adjustment Triggered by Resource Congestion

In case of uplink or downlink resource congestion, the RNC must reduce the rates of

AMR services in accordance with their priorities.

When uplink or downlink resources are not congested and the NB-AMR services whose

rates are reduced meet the conditions described in section 3.3.2 Iu UP Initialization, the

RNC increases their rates level by level.

When the switch of forbidding AMR downgrade is turned on (URncInfo.loadForAmrSwit

is 1: forbidden), the AMR downgrade triggered by congestion control is not performed. If

URncInfo.loadForAmrSwit is 0, the original congestion control downgrade policy is

recovered. For details, refer to the ZTE UMTS Congestion Control Feature Guide.

NB-AMR Rate Control


3.3 ZWF21-06-002 TrFO

In the R99 phase, 64 kbit/s PCM coding is used based on the TDM bearer in the CN CS

domain. Therefore, the R99 MSC must have the voice TC function. However, voice

quality may be reduced after encoding or decoding. The calls between mobile users

need dual voice encoding and decoding. If no codec is used, voice quality can be

improved and network bandwidth can be saved.

In the R4 phase, a TrFO connection can reduce the number of times that voice encoding

and decoding are performed. The TrFO connection can be established throughout the

end-to-end process or between the nodes of a call connection. For example, for a call

between a UMTS UE and a fixed telephone, the TrFO connection only exists between

the UMTS UE and the core network. The core network and the RNC in the TrFO

connection must support Iu UP V2. Otherwise, no TrFO connection can be established.

ZTE supports both Iu UP V1 and Iu UP V2, and the RNC is selected according to CN

RAB assignment parameters.

The TrFO is implemented through Out of Band Transcoder Control (OoBTC). It is

applicable to the calls between mobile networks and those between a mobile network

and an external network. When the same voice encoding or decoding type is used

between both call parties or between one call party and a node in the call connection, the

TrFO can transparently transmit the compressed voice, and this improves voice quality

and saves transmission bandwidth.

The nodes connected with a TrFO connection use the same common compressed voice

encoding type negotiated in the OoBTC phase. A codec must be inserted between a

TrFO connection and a non-TrFO connection to convert encoding types. The

implementation strategy of the core network ensures that the insertion position can meet

the following requirements:

The insertion position should reduce the number of times that TC (transcoder) is

used and improve voice quality;

The insertion position should save transmission bandwidth. This indicates that it

should prolong the connection that uses compressed voice encoding data for

transmission.

NB-AMR Rate Control


During Iu UP initialization, if the CN supports both Iu UP version 1 and version 2, ZTE's

RNC uses URncFunction.intraRatV1V2AmrCut to determine whether to cut NB-AMR

rates according to the RNC capability between the CN and the RNC in the RAB

assignment procedure and inter-RNC relocation procedure, and ZTE's RNC uses

URncFunction.interRatV1V2AmrCut to determine whether to cut NB-AMR rates

according to the RNC capability between the CN and the RNC in the inter-RAT relocation

procedure.

For a UTRAN, its Iu UP initialization, reverse initialization, Iu UP rate control, and Iu UP

reverse rate control are related to the TrFO process.

3.3.1 OoBTC Out of Band Transcoder Control

When a call is initiated, both call parties negotiate the codec to establish a TrFO

operation. The O-MSC sends an IAM message containing the supported codec type list

to a transmission network. The transmission network deletes the codec types that are not

supported from the list and sends it to a T-MSC. The T-MSC also deletes the codec

types that are not supported from the list and then selects an optimal common codec

type. The T-MSC returns the codec type to the transmission network and the O-MSC,

and notifies them of the selected codec type. In the meantime, the T-MSC returns the

codec type that the Terminating UE supports to the O-MSC and begins to establish a

bearer based on this codec. This flow is shown in the following figure.

NB-AMR Rate Control


Figure 3-2 Flow of OoBTC Out of Band Transcoder Control

Codec List (v, w, x, y, z)

Codec List (v, w, x, z)

O-MSC Transit T-MSC

O-MGW T-MGWTransit

MGW

Selected Codec = v, Available List (v, x, z, )

Selected Codec = v

Selected Codec = v

Selected Codec = v, Available

List (v, x, z, )

Selected Codec = v

Bearer Established Bearer Established

The encoding type that the UE supports is transparently transmitted to the RNC as

follows: Uplink Direct Transfer -> NAS Message -> Bearer Capacity, and then the RNC

transparently transmits the encoding type to the MSC server as follows: Direct Transfer ->

NAS Indicator -> Bearer Capacity. During RAB assignment, the encoding/decoding type

lists of the calling and called parties are completely the same.

3.3.2 Iu UP Initialization

The purpose of Iu UP initialization is to define the mapping relationship (used in the data

transmission phase) between the RNC and the CN on both sides of Iu UP, including RAB

sub-flow combination, RFCIs, and SDU size of the related RAB sub-flow.

If a bearer is successfully established, the CN delivers an RAB assignment request

message to the RNC. The RNC in the R4 version must support all the SDU sub-flow

combinations in the RAB assignment request message. This indicates that the content in

the initialization frame is a universal set of sub-flow combinations determined by RAB

assignment. Therefore, the initialization frame is only used to negotiate Iu UP version

NB-AMR Rate Control


information and RFCI correspondence (each RFCI corresponds to a sub-flow

combination).

In the R99 version, this initialization process can only be performed when the RNC

receives an RAB assignment, modification, or RNC relocation request. In the R4 version,

the CN can also perform this initialization process, which is called Iu UP reverse

initialization. The following figure shows Iu UP initialization.

Figure 3-3 Iu UP Initialization

*

Transfer Of User Data

CN/ RNC

INITIALISATION

((RFCI, SDU sizes[, IPTIs 2) ]) m )

INITIALISATION ACK

* can be repeated N INIT times 2) optional

RNC/ CN

In the RFCI set determined during Iu UP initialization, the rate that corresponds to the

first RAB sub-flow combination is the highest rate in the initialization response direction

permitted by the local end when data transmission begins. The highest rate must be

higher than the guaranteed rate and SID rate. The highest rate can be modified during Iu

UP rate control after Iu UP initialization. The rates higher than the guaranteed rate are

called controllable rates, and the rates lower than the guaranteed rate cannot be

modified.

3.3.3 Iu UP Rate Control

The purpose of Iu UP rate control is to notify the peer Iu UP protocol layer of the highest

rate at the Iu interface in the reverse direction of the rate control frame. In the R4 version,

Iu UP rate control can be initiated by the RNC or the CN. In the R99 version, Iu UP rate

control can only be initiated by the RNC.

As long as an Iu UP entity is not suspended by other control flows, it can initiate rate

control. The controlled rates are all included in the RFC set determined during Iu UP

initialization. These rates that correspond to the RFC should be higher than the

NB-AMR Rate Control


guaranteed rate. Rate control cannot be implemented when the SID rate and the RFC

are lower than the guaranteed rate because they cannot be prohibited.

Figure 3-4 Flow of Iu UP Rate Control

CN/ RNC

RNC/ CN

RATE CONTROL

(RFCI indicators)

RATE CONTROL ACK

(RFCI indicators)

Note: The rate control frame describes the limits of an RFC set, hereinafter called the

"RFC limit set".

In downlink direction, the RNC triggers the rate control frame, records the "RFC limit set"

(downlink direction), and monitors the operations of the CN. If the CN sends the data

frame of the limited RFCI, the rate control frame must be resent. In uplink direction, the Iu

UP module of the RNC receives the rate control frame and implements the limit through

TFC control.

The rate control initiated by the CN is as follows: After receiving a rate control message

from the RNC, the CN initiates rate control to the other party of the call to limit or open the

other party's uplink AMR level, or the CN initiates a rate adjustment flow according to the

TrFO. For example, during SRNS relocation, the CN performs reverse initialization first

after a new RNC sends relocation detection to the CN, and then the new RNC initiates a

process called immediate initialization. This aims at negotiating the highest rate for data

transmission between two Iu UP entities supporting TrFO.

The rate control initiated by the RNC is as follows: During the dynamic AMR process, the

RNC adjusts the downlink AMR level according the downlink load of a cell or the

dedicated TCP measurement of an RL and initiates rate control.

Compared with the encoding and decoding type negotiation before initialization, Iu UP

rate control is in-band rate control.

NB-AMR Rate Control


4 Parameters

4.1 ZWF21-02-001 Conversational RAB for AMR

Table 4-1 Parameter Description

Parameter

Name GUI Name Parameter Description

Value

Range Unit

Default

Value

Recom

mende

d Value

ULogicalRnc.a

mrNbMode0Us

eTag

AMR_NB

4.75k Use Tag

This parameter

indicates whether the

RNC supports AMR

4.75 kbps in Iu UP

version 1. It is used in

the user plane

initialization process of

RAB establishment or

SRNS relocation.

0:Not

Used

1: Used

N/A 0:Not

Used

0:Not

Used

ULogicalRnc.a

mrNbMode1Us

eTag

AMR_NB

5.15k Use Tag

This parameter


RNC supports AMR

5.15 kbps in Iu UP


the user plane



SRNS relocation.

0: Not

Used

1: Used

N/A 0:Not

Used

0:Not

Used

ULogicalRnc.a

mrNbMode2Us

eTag

AMR_NB

5.90k Use Tag

This parameter


RNC supports AMR

5.90 kbps in Iu UP


the user plane



SRNS relocation.

0: Not

Used

1: Used

N/A 0:Not

Used

0:Not

Used

ULogicalRnc.a

mrNbMode3Us

AMR_NB

6.70k Use Tag

This parameter


0: Not

Used N/A

0:Not

Used

0:Not

Used

NB-AMR Rate Control


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

eTag RNC supports AMR

6.70 kbps in Iu UP


the user plane



SRNS relocation.

1: Used

ULogicalRnc.a

mrNbMode4Us

eTag

AMR_NB

7.40k Use Tag

This parameter


RNC supports AMR

7.40 kbps in Iu UP


the user plane



SRNS relocation.

0: Not

Used

1: Used

N/A 0:Not

Used

0:Not

Used

ULogicalRnc.a

mrNbMode5Us

eTag

AMR_NB

7.95k Use Tag

This parameter


RNC supports AMR

7.95 kbps in Iu UP


the user plane



SRNS relocation.

0: Not

Used

1: Used

N/A 0:Not

Used

0:Not

Used

ULogicalRnc.a

mrNbMode6Us

eTag

AMR_NB

10.2k Use Tag

This parameter


RNC supports AMR

10.2 kbps in Iu UP


the user plane



SRNS relocation.

0: Not

Used

1: Used

N/A 0:Not

Used

0:Not

Used

ULogicalRnc.a

mrNbMode7Us

eTag

AMR_NB

12.2k Use Tag

This parameter


RNC supports AMR

0: Not

Used

1: Used

N/A 1:Used 1:Used

NB-AMR Rate Control


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

12.2 kbps in Iu UP


the user plane



SRNS relocation.

URncFunction.

amrGbrResInd

GBR of AMR

Service

Whether to be

Reserved

Indicator

This parameter


GBR rate assigned by

the CN is forcibly

reserved in Iu UP V1

mode, when the GBR

rate assigned by the CN

does not match the

AMR rate configured by

RNC.

0: False

1: True N/A 1 1

URncInfo.Intra

RlocAmrRtCtrl

AMR Rate

Control Switch

after

Relocation

The parameter is used

to indicates whether

narrowband or

wideband AMR service

rate is allowed to be

changed after the

relocation or not. "0"

indicates rate changing

after relocation is not

allowed. while "1"

indicates rate changing

after relocation is

allowed.

0: AMR

Rate

Changi

ng is

Allowed

after

Relocati

on

1: AMR

Rate

Changi

ng is

Not

Allowed

after

Relocati

on

N/A

0: AMR

Rate

Changi

ng is

Allowed

after

Relocat

ion

0: AMR

Rate

Changi

ng is

Allowed

after

Relocat

ion

URncFunction.

interRatV1V2A

mrCut

Inter-RAT

V1+V2 Amr

Cut Decision

Specifies the Amr cut

decision when IuUP

version including

V1+V2 in the inter-RAT

1: cut

2: not

cut

N/A 1: cut 1: cut

NB-AMR Rate Control


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

case

URncFunction.

intraRatV1V2A

mrCut

Intra-RAT

V1+V2 Amr

Cut Decision


decision when IuUP

version including

V1+V2 in the intra-RAT

case

1: cut

2: not

cut

N/A 2: not

cut

2: not

cut

4.2 ZWF21-04-005 AMR Rate Controlling

4.2.1 Uplink Rate Adjustment Based on the UE Transmitted Power


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

ULogicalRnc.a

mrRncAdjust

AMR Rate

Adjustment

Switch for

RNC

This parameter

indicates whether AMR

rate adjustment is

supported in the RNC.

0: Off

1: On N/A 0:Off 1:On

UUtranCellFD

D.refUUeIntMe

asProfile

Used UE

Internal

Measurement

Profile

This parameter is the

DN (Distinguish Name)

of UUeIntMeasProfile.

0..6553

5, step

1

N/A N/A N/A

UUeIntMeasPr

ofile.profileId Profile Id

ID of UE internal

measurement Profile

0..9,

step 1 NA NA N/A

UAmrEvtTPUe

Int.ueIntMCfgN

o

UE Internal

Measurement

Configuration

Index

This parameter is used

for indexing the

configuration of the

parameters of UE

transmitted power event

report for AMR

dyanamical rate control.

0..6553

5, step

1

long N/A N/A

UAmrEvtTPUe Measurement This parameter 0: N/A 0:Ackn 0:Ackn

NB-AMR Rate Control


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

Int.measRptTr

Mod

Report

Transfer Mode

indicates the RLC mode

of the UE internal

measurement report. If

the value is AM RLC,

RNC can request UE for

retransmission after

receiving the error SDU

label (not continuous). If

the value is UM RLC,

the retransmission is

not required. Usually,

report the results of the

important

measurements in AM

mode and those less

important in UM mode

(to reduce the traffic

volume of the

measurement report

and increase the

system capacity).

Acknow

ledged

Mode

RLC

1:

Unackn

owledg

ed

Mode

RLC

owledg

ed

Mode

RLC

owledg

ed

Mode

RLC

UAmrEvtTPUe

Int.filterCoeff

Filter

Coefficient

This parameter

indicates the filtering

factor that UE performs

the L3 filtering on the

measurement results of

the internal

measurement.

(0, 1,

2, 3, 4,

5, 6, 7,

8, 9, 11,

13, 15,

17, 19)

N/A 3 3

UAmrEvtTPUe

Int.measEvtNu

m

Maximum

Event Number

of UE Internal

Measurement

This parameter

indicates the maximum

event number of UE

internal measurement.

1..7,

step 1 N/A 2 2

UAmrEvtTPUe

Int.meaEvtId

UE Internal

Measurement

Event Identity

This parameter

indicates the UE

internal measurement

event identity.

[6a, 6b,

6f, 6g] N/A [6a, 6b] [6a, 6b]

UAmrEvtTPUe Time to Trigger This parameter (0, 10, ms [1280, [1280,

NB-AMR Rate Control


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

Int.trigTime indicates the period of

time during which the

event condition has to

be satisfied before

sending a measurement

report.

20, 40,

60, 80,

100,

120,

160,

200,

240,

320,

640,

1280,

2560,

5000)m

s

1280] 1280]

UAmrEvtTPUe

Int.txPowerThr

es

UE

Transmitted

Power

Threshold

This parameter

indicates the UE

transmitted power

threshold in event

6a/6b.

(-50,

0)dB,

step1

dB

dB [-1, -2] [-1, -2]

USrvDivPc.ma

xUlDpchPwr

Maximum

Allowed Uplink

DPCH

Transmission

Power

This parameter

indicates the maximum

DPCH uplink transmit

power allowed for a UE.

When uplink inner loop

power control is

performed, the transmit

power newly calculated

by a UE may be larger

than this parameter. In

this case, the UE can

only use this parameter

for transmitting signals.

This parameter is a

nine-element array.

These elements are

used in different load

conditions and user

priorities. The

corresponding

(-50..33

)dBm,

step

1dBm

dBm

[33,33,

33,33,3

3,33,33

,33,33]

[33,33,

33,33,3

3,33,33

,33,33]

NB-AMR Rate Control


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

relationships of the

elements and load

levels and user

priorities are as follows:

Element 1: low load,

gold medal user


silver medal user


bronze medal user

Element 4: medium

load, gold medal user

Element 5: medium

load, silver medal user

Element 6: medium

load, bronze user

Element 7: high load,

gold medal user


silver medal user


bronze medal user

4.2.2 Downlink Rate Adjustment Based on the Dedicated Measurement of

Node B Transmitted Power


Parameter

Name GUI Name Parameter Description Value Range Unit

Default

Value

Reco

mmen

ded

Value

ULogicalR

nc.amrRnc

Adjust

AMR Rate

Adjustment

Switch for

RNC

This parameter indicates

whether AMR rate

adjustment is supported

in the RNC.

0: Off

1: On N/A 0:Off 1:On

UNbDedM Profile Id This parameter indicates 0..9 NA NA N/A

NB-AMR Rate Control


Parameter


Default

Value

Reco

mmen

ded

Value

easProfile.

profileId

the Profile Id for the

NodeB dedicated

measurement. Each

profile corresponds one

setting of NodeB

dedicated measurement

parameters.

UNbDedM

eas.nbDM

CfgNote

Function of

Configuration

Parameters


the function, purpose

etc. of the dedicated

measurement

parameters indicated by

the configuration index.

0: Period

Report

Parameters for

TCP in Power

Balance

1: Period

Report

Parameters for

TCP in AMR or

DASF-PS or

Handover

Control

2: Event A

Report

Parameters for

TCP in

DASF-PS

3: Event B

Report

Parameters for

TCP in

DASF-PS

4: Period

Report

Parameters for

RTT in LCS

5: Event E

Report

Parameters for

SIR Error in

N/A

7: Event

A Report

Paramet

ers for

TCP in

AMR

8: Event

B Report

Paramet

ers for

TCP in

AMR

7:

Event

A

Report

Param

eters

for

TCP in

AMR

8:

Event

B

Report

Param

eters

for

TCP in

AMR

NB-AMR Rate Control


Parameter


Default

Value

Reco

mmen

ded

Value

Outer Loop

Power Control

6: Event F

Report

Parameters for

SIR Error in

Outer Loop

Power Control

7: Event A

Report

Parameters for

TCP in AMR

8: Event B

Report

Parameters for

TCP in AMR

9: Event A

Report

Parameters for

TCP in

Handover

Control

10: Event B

Report

Parameters for

TCP in

Handover

Control

UNbDedM

eas.dedM

easType

Dedicated

Measurement

Type


the type of dedicated

measurement to be

executed by Node B

1: SIR Error

2: Transmitted

Code Power

5: Round Trip

Time

N/A

2:

Transmit

ted Code

Power

2:

Trans

mitted

Code

Power

UNbDedM

eas.meas

FilterCoeff

Measurement

Filter

Coefficient


how filtering of the

measurement values

shall be performed

( 0, 1, 2, 3, 4,

5, 6, 7, 8, 9,

11, 13, 15, 17,

N/A 2 2

NB-AMR Rate Control


Parameter


Default

Value

Reco

mmen

ded

Value

before measurement

event evaluation and

reporting.

The averaging shall be

performed according to

the following formula.

F(n) =(1-a)* F(n-1) +

a*M(n)

The variables in the

formula are defined as

follows:

F(n) is the updated

filtered measurement

result

F(n-1) is the old filtered

measurement result

Mn is the latest received

measurement result from

physical layer

measurements

a = (1/2)^ (k/2) , where k

is the Measurement

Filter Coefficient. If k=1

there’s no filtering)

In order to initialise the

averaging filter, F(0) is

set to M(1) when the first

measurement result from

the physical layer

measurement is

received.

19)

UNbDedM

eas.rptTyp

e

Report

Characteristic

s


the report characteristics

of measurement results,

which can be on

demand, periodic or by

triggering all kinds of:

1: On Demand

2: Periodic

3: Event A

4: Event B

5: Event C

6: Event D

N/A 2:

Periodic

2:

Period

ic

NB-AMR Rate Control


Parameter


Default

Value

Reco

mmen

ded

Value

events. 7: Event E

8: Event F

UNbDedM

eas.evtAb

TcpThrd

Measurement

Threshold of

Event A/B for

Transmitted

Code Power


the power offset of the

DPCH maximum DL

power, which defines

which threshold that

shall trigger event A, B

for transmitted carrier

power measurement.

In PS DRBC, this

threshold is related to

the service rate as

following:

Rate Level PS Service

Rate (R) Threshold of

Event A/B

Level 1 R<=

DlRateLevel[0]

EvtAbTcpThrd [0]

Level 2

DlRateLevel[0]<R<=

DlRateLevel[1]

EvtAbTcpThrd [1]

Level 3

R>DlRateLevel[1]

EvtAbTcpThrd [2]

Other case, the

threshold and service

rate independent, and

the threshold is

EvtAbTcpThrd [0].

(-50..0)dB,

step 0.1dB dB

[-0.4,-1.6

]

[-0.4,-

1.6]

UNbDedM

eas.evtAb

cdefTime

Measurement

Change

Time/Measur

ement

For event A/B/E/F, this

parameter is

measurement hysteresis

time and the

(10..60000)ms,

step 10ms

ms 100 100

NB-AMR Rate Control


Parameter


Default

Value

Reco

mmen

ded

Value

Hysteresis

Time

measurement hysteresis

time provides the

duration during which a

reporting criterion has to

be fulfilled for the

Measurement Reporting

procedure to be

triggered.

For event C/D, this

parameter is change

time. and the change

time is the time the

measurement entity shall

rise on (in ms), in order

to trigger a measurement

report.

UNbDedM

eas.rptPrd

Unit

Choice

Report

Periodicity

Scale


the report period unit

applied by Node B for

measurement result

reporting.

1: ms

2: min N/A ms ms

UNbDedM

eas.rptPrd Report Period


the frequency of

measurement report

transmitted by Node B.

RptPrdUnit =1:

(10..60000)ms,

step 10ms

RptPrdUnit =2:

(1..60)min step

min

ms 1000 1000

USrvDivPc

.maxDlDpc

hPwr

DPCH

Maximum DL

Power


the maximum DPCH

downlink transmit power.

When downlink inner

loop power control is

performed, new transmit

power must be smaller

than or equal to the

configured DPCH

(-35..15)dB,

step 0.1dB dB

[3,3,3,3,

0,0,3,0,0

]

[3,3,3,

3,0,0,

3,0,0]

NB-AMR Rate Control


Parameter


Default

Value

Reco

mmen

ded

Value

Maximum DL Power. If

the newly calculated

transmit power is larger

than the configured

DPCH Maximum DL

Power, set it to be equal

to the configured DPCH

Maximum DL Power.

This parameter is a

nine-element array.

These elements are

used in different load

conditions and user

priorities. The

corresponding

relationships of the

elements and load levels

and user priorities are as

follows:

Element 1: low load, gold

medal user


silver medal user


bronze medal user

Element 4: medium load,

gold medal user


silver medal user


bronze user


gold medal user


silver medal user


bronze medal user

NB-AMR Rate Control


Parameter


Default

Value

Reco

mmen

ded

Value

UDrbc.dtc

pEaThd

Event A

Counter

Threshold for

PS on DL

DCH or DL

AMR

Decreasing

Rate Based

on D-TCP


the reported times of

threshold of DTCP

measurement event A. If

the times of the event A

that only uses TCP is

larger than this

threshold, the speed of

downlink PS or AMR will

be reduced.

1..255 N/A 2 2

UDrbc.dtcp

EbThd

Event B

Counter

Threshold for

Restriction

PS

Increasing

Rate on DL

DCH or

Triggering DL

AMR

Increasing

Rate Based

on D-TCP


the event B counter

threshold of consecutive

DTCP reports. If the

times of dedicated

transmitted code power

is less than the event B

threshold exceed the

threshold indicated by

this parameter, it will

trigger the downlink AMR

increasing rate or allow

PS services to increase

rate on DL DCH based

on traffic volume report.

1..255 N/A 2 2

4.2.3 Dynamic Adjustment Triggered by Load and Resource Congestion


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

URncInfo.conF

orbAmrSwit

Switch of

Forbidding

AMR


switch of forbidding

AMR deceleration

0: not

forbidde

n

N/A

0: not

forbidd

en

0: not

forbidd

en

NB-AMR Rate Control


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

Deceleration

Triggered by

Congestion

Control

triggered by congestion

control. When the

switch is on, AMR

speed is forbidden even

resource is congested.

1:

forbidde

n

URncInfo.load

ForAmrSwit

Switch of

Forbidding

AMR

Deceleration

Triggered by

Overload

Control


switch of forbidding

AMR deceleration

triggered by overload

control. When the

switch is on, AMR

speed is forbidden even

resource is overload.

0: not

forbidde

n

1:

forbidde

n

N/A

0: not

forbidd

en

0: not

forbidd

en

4.3 ZWF21-06-002 TrFO


Parameter


Value

Range Unit

Default

Value

Recom

mende

d Value

URncFunction.

interRatV1V2A

mrCut

Inter-RAT

V1+V2 Amr

Cut Decision


decision when IuUP

version including

V1+V2 in the inter-RAT

case

1: cut

2: not

cut

N/A 1: cut 1: cut

URncFunction.

intraRatV1V2A

mrCut

Intra-RAT

V1+V2 Amr

Cut Decision


decision when IuUP

version including

V1+V2 in the intra-RAT

case

1: cut

2: not

cut

N/A 2: not

cut

2: not

cut

NB-AMR Rate Control


5 Related Counters and Alarms

5.1 Related Counters

Table 5-1 Counters

Counter ID Name

C310030466 Number of CS AMR 12.2k in the best cell








C310030638 Number of CS AMR 12.2k in the non-best cell








C310063411 Number of CS AMR 12.2k in the DRNC cell








NB-AMR Rate Control


C310040001 Holding time for the best cell,AMR12.2








C310040075 Holding time for the non-best cell,AMR12.2








C310073296 Holding time for the DRNC cell,AMR12.2
















NB-AMR Rate Control


C310291927 Number of abnormal release RAB by Uu-fail,CS,AMR

12.2


10.2


7.95


7.4


6.7


5.9


5.15


4.75

C310373796 Number ofRAB by RAB releasefor

CS,conversation:AMR 12.2















C310800164 Max Number of DC+MIMO users in NodeB

C310800165 Current Number of DC+MIMO users in NodeB

C310231185 Total number of RABrelease for CS domain,AMR 12.2


NB-AMR Rate Control


C310231187 Total number ofRABreleasefor CS domain,AMR 7.95






C310231231 Number of RNC initiate RAB release by Iu release

request for CS domain,AMR 12.2















C310231162 Number of RAB abnormal release for CS domain,AMR

12.2


10.2


7.95


7.4


6.7


5.9


NB-AMR Rate Control


5.15


4.75

5.2 Related Alarms

This feature has no related alarms.

6 Engineering Guide

6.1 Application Scenario

6.1.1 ZWF21-02-001 Conversational RAB for AMR

With this feature, users can make calls on the ZTE UMTS network. This feature is a basic

feature of UMTS networks.


With this feature, ZTE's RNC can adjust the uplink and downlink NB-AMR rates based on

the UE uplink transmit power and NodeB downlink transmit power respectively, or adjust

AMR rates during resource congestion. This feature improves cell capacity and user

experience when radio link quality is reduced.

6.1.3 ZWF21-06-002 TrFO

With this feature, Out of Band Transcoder Control (OoBTC) can be used during NB-AMR

service establishment to implement consistent voice encoding and decoding negotiation

between the UE and the network. In this way, the TC (Transcoder) is not necessary and

coded voice data is transmitted transparently between users. This improves voice quality

and saves transmission bandwidth between core networks.

NB-AMR Rate Control


6.2 Feature Activation Procedure


None.


6.2.2.1 Uplink Rate Adjustment Based on the UE Transmit Power

In the configuration resource tree, select Modify Area > Managed Element > UMTS

Logical Function Configuration > PLMN Relating Configuration > Logic RNC

Configuration and set AMR Rate Adjustment Switch for RNC, see the following

figure.

Figure 6-1 Parameter Configuration Interface 1


Logical Function Configuration > UTRAN Cell and set Used UE Internal

Measurement Profile to default, see the following figure.

NB-AMR Rate Control




Logical Function Configuration > Service Configuration > Measurement

Configuration > UE Internal Measurement Profile and set Profile ID to default, see

the following figure.




NB-AMR Rate Control


Configuration > UE Internal Measurement Profile > UE Transmitted Power Event

Measurement Configuration for AMR and set Measurement Report Transfer Mode,

Filter Coefficient, Maximum Event Number of UE Internal Measurement, UE

Internal Measurement Event Identity, Time to Trigger, and UE Transmitted Power

Threshold, see the following figure.



Logical Function Configuration > Service Configuration > Service Function >

Power Control Profile Related to Service > Power Control Related to Service >

Power Control Related to Service and Diversity Mode and set Maximum Allowed

Uplink DPCH Transmission Power, see the following figure.

NB-AMR Rate Control



6.2.2.2 Downlink Rate Adjustment Based on the Dedicated Measurement of NodeB

Transmit Power


Logical Function Configuration > PLMN Relating Configuration > Logic RNC

Configuration and set AMR Rate Adjustment Switch for RNC, see the following

figure.

NB-AMR Rate Control





Configuration > NodeB Dedicated Measurement Profile and set Profile Id to default,

see the following figure.


NB-AMR Rate Control




Configuration > NodeB Dedicated Measurement Configuration and set Function of

Configuration Parameters, Dedicated Measurement Type, Measurement Filter

Coefficient, Report Characteristics, Measurement Threshold of Event A/B for

Transmitted Code Power, Measurement Change Time/Measurement Hysteresis

Time, Choice Report Periodicity Scale, and Report Period, see the following figure.




Configuration > NodeB Dedicated Measurement Configuration and set DPCH

Maximum DL Power to default, see the following figure.

NB-AMR Rate Control




Logical Function Configuration > Global Information Configuration > Dynamic

Radio Bearer Control Information Profile > Dynamic Radio Bearer Control

Information and set Event A Counter Threshold for PS on DL DCH or DL AMR

Decreasing Rate Based on D-TCP and Event B Counter Threshold for Restriction

PS Increasing Rate on DL DCH or Triggering DL AMR Increasing Rate Based on

D-TCP to default, see the following figure.


NB-AMR Rate Control


6.2.2.3 Dynamic Adjustment Triggered by Load and Resource Congestion


Logical Function Configuration > Global Information Configuration > Dynamic

Radio Bearer Control Information Profile > Dynamic Radio Bearer Control

Information and set Switch of Forbidding AMR Deceleration Triggered by

Congestion Control and Switch of Forbidding AMR Deceleration Triggered by

Overload Control to default, see the following figure.


6.2.3 ZWF21-06-002 TrFO


Logical Function Configuration and set S Intra-RAT V1+V2 Amr Cut Decision and

Inter-RAT V1+V2 Amr Cut Decision, see the following figure.

NB-AMR Rate Control



6.3 Feature Validation Procedure


N/A


Table 6-1 Feature Validation Procedure

Test Item AMR Rate Controlling based on UE TxPower

Prerequisit

es

1. The WCDMA system is ready.

2. Cell1 supports HSUPA, HSDPA, and DCH.

3. Both the CN and the RNC support multiple rates for AMR. Uplink

and downlink AMR voice supports the rates of 12.2 kbps, 7.4 kbps,

5.15 kbps, and 4.75 kbps.

4. UE1 and UE2 camp on Cell1 in idle mode.

Steps

1. UE1 makes an AMR voice call to UE2 in Cell1.

2. UE1 is deleted from Cell1 to trigger event 6A. The uplink AMR rate

of UE1 is decreased.

3. UE1 is added to Cell1 to trigger event 6B. The uplink AMR rate of

UE1 is increased.

4. The voice call is released.

NB-AMR Rate Control


Test Item AMR Rate Controlling based on UE TxPower

Expected

Result

1. The initial and highest bit rate of the AMR voice service is 12.2

kbps.

2. The AMR rate adaptation procedure is normal.

6.3.3 ZWF21-06-002 TrFO

N/A

6.4 Feature Deactivation Procedure


N/A


Table 6-2 RNC Parameter

No Parameter Name Default Value Deactivation Value

1 AMR Rate Adjustment

Switch for RNC 0:Off 0:Off

6.4.3 ZWF21-06-002 TrFO

The CN deactivates the feature.

6.5 Impact on the Network


1) Impact on Equipment Performance

None.

NB-AMR Rate Control


2) Impact on Network KPIs

Advantages of this feature:

Users can make NB-AMR conversational calls in the UMTS network.

Disadvantages of this feature:

None.



None.



With this feature, ZTE's RNC can adjust the uplink and downlink NB-AMR rates based on

the UE uplink transmit power and NodeB downlink transmit power respectively, or adjust

AMR rates during resource congestion. This feature improves cell capacity and user

experience when radio link quality is reduced.


Voice quality is slightly reduced when the NB-AMR rate is reduced.

6.5.3 ZWF21-06-002 TrFO


None.



NB-AMR Rate Control


With this feature, Out of Band Transcoder Control (OoBTC) can be used during NB-AMR

service establishment to implement consistent voice encoding and decoding negotiation

between the UE and the network. In this way, the TC (Transcoder) is not necessary and

coded voice data is transmitted transparently between users. This improves voice quality

and saves transmission bandwidth between core networks.


None.

7 Abbreviations Abbreviation Full Name

3GPP 3rd Generation Partnership Project

UE User Equipment

NB-AMR Narrow Band Adaptive Multi-Rate

WB-AMR Wide Band Adaptive Multi-Rate

TrFO Transcoder Free Operation

OoBTC Out-of-Band Transcoder Control

TC Transcoder

8 Reference Documents

[1]ZXUR 9000 UMTS(V4.13.10.15)Radio Network Controller Radio Parameter

Reference

[2]ZXUR 9000 UMTS(V4.13.10.15)Radio Network Controller Ground Parameter

Reference

[3]ZXUR 9000 UMTS(V4.13.10.15)Radio Network Controller Performance Counter

Reference

[4]ZXWR RNC(V3.13.10.15)Radio Network Controller Radio Parameter Reference

[5]ZXWR RNC(V3.13.10.15)Radio Network Controller Ground Parameter Reference

NB-AMR Rate Control


[6]ZXWR RNC(V3.13.10.15)Radio Network Controller Performance Counter Reference

[7]ZTE UMTS Directed Retry to GSM Feature Guide

[8]ZTE UMTS Power Control Feature Guide

[9]ZTE UTMS Overload Control Feature Guide

[10]ZTE UMTS Congestion Control Feature Guide

[11]ZTE UMTS Adaptive Radio Bearer Feature Guide

zte umts nb-amr rate control feature guide

Documents

amr rate controlling

nbamr service

nbamr rate selection

nbamr mobility

amr rates

amr speech

rab modification of

proprietary information