Content for TS 45.009 Word version: 16.0.0
1 Scope Word‑p. 5
The requirements described in the present document are mandatory for implementation in all GSM MSs and BSSs capable of supporting the Adaptive Multi-Rate speech traffic channel, unless otherwise stated.
Unless otherwise specified, references to GSM include GSM at any frequency band.
1.1 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
[1]
TR 21.905: "Vocabulary for 3GPP Specifications".
[2]
TS 44.018: "Mobile radio interface layer 3 specification, Radio Resource Control Protocol".
[3]
TS 45.002: "Multiplexing and multiple access on the radio path".
[4]
TS 45.003: "Channel Coding".
[5]
TS 45.005: "Radio transmission and reception".
[6]
TS 48.008: "Mobile-services Switching Centre - Base Station System (MSC - BSS) interface, Layer 3 specification".
[7]
TS 28.062: "Inband Tandem Free Operation (TFO) of Speech Codecs".
1.2 Abbreviations
For the purposes of the present document, the following abbreviations apply. Further GSM related abbreviations are listed in TR 21.905.
AMR
Adaptive Multi-Rate
AMR-WB
Adaptive Multi-Rate Wideband
ACS
Active Codec Set
CMC
Codec Mode Command
CMI
Codec Mode Indication
CMR
Codec Mode Request
ICM
Initial Codec Mode
RATSCCH
Robust AMR Traffic Synchronized Control Channel
2 General
The present document gives the detailed requirements for the correct operation of in call service specific link adaptation and control for GSM services implemented in GSM Mobile Stations (MS)s and Base Station Systems (BSS)s.
In this specification the term AMR refers to both narrow-band and wide-band AMR codecs if not otherwise stated.
For the Adaptive Multi-Rate (AMR) speech service, the detailed description and requirements for the associated inband signaling, AMR codec mode adaptation, and AMR codec configuration are given.
An inband signalling channel is defined for AMR which enables the MS and the BTS to exchange messages on applied or requested speech and channel codec modes. Codec mode adaptation for AMR is based on received channel quality estimation in both MS and BTS, followed by a decision on the most appropriate speech and channel codec mode to apply at a given time.
The overall operation of AMR, in terms of used codec modes as well as general adaptation behaviour is controlled by the network.
