AMR-WB
Encyclopedia
Adaptive Multi-Rate Wideband (AMR-WB) is a patent
ed speech coding
standard developed based on Adaptive Multi-Rate
encoding, using similar methodology as Algebraic Code Excited Linear Prediction (ACELP). AMR-WB provides improved speech quality due to a wider speech bandwidth of 50–7000 Hz compared to narrowband speech coders which in general are optimized for POTS
wireline quality of 300–3400 Hz.
AMR-WB is codified as G.722.2, an ITU-T
standard speech codec, formally known as Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB). G.722.2 AMR-WB is the same codec as the 3GPP
AMR-WB. The corresponding 3GPP specifications are TS 26.190 for the speech codec and TS 26.194 for the Voice Activity Detector.
A common file extension for AMR-WB file format is
container format based on ISO base media file format
. 3GP also allows use of AMR-WB bit streams for stereo sound.
with 9 different bit rates. The lowest bit rate providing excellent speech quality in a clean environment is 12.65 kbit/s. Higher bit rates are useful in background noise conditions and for music. Also lower bit rates of 6.60 and 8.85 kbit/s provide reasonable quality especially if compared to narrow band codecs.
All modes are sampled at 16 kHz (using 14 bit resolution) and processed at 12.8 kHz.
The bit rates are the following:
This limitation was designed to simplify the negotiation of bitrate between the handset and the base station, thus vastly simplifying the implementation and testing. All other bitrates can still be used for other purposes in mobile phone networks, including multimedia messaging, streaming audio, etc.
In October 2006, first AMR-WB tests were conducted in a deployed network by T-Mobile in Germany, in cooperation with Ericsson.
In 2007 end-to-end AMR-WB TrFO capable 3G & VoIP product line was commercially released by NSN
(M13.6 MSS
, U3C MGW
). AMR-WB TFO support commercially released in 2008 (M14.2, U4.0). End-to-end TFO/TrFO negotiation and mid-call optimization (e.g. on handover
, CF
or CT
events) released in 2009 (M14.3, U4.1).
In late 2009, Orange (UK) announced that it would be introducing AMR-WB on its network in 2010.
In France Orange and SFR are using this codec on their 3G+ networks since the end of 2010 summer.
WIND Mobile in Canada launched HD Voice (AMR-WB) on its 3G+ network in February, 2011. WIND Mobile also announced that several handsets will support HD Voice (AMR-WB) in first half of 2011. WIND Mobile press release on HD voice First one being Alcatel Tribe.
Nokia
developed VMR-WB
codec for CDMA2000
networks, which is fully interoperable with 3GPP AMR-WB.
AMR-WB is also widely adapted format in mobile handsets for tones.
The AMR wideband speech codec shall be supported in 3G
multimedia services when wideband speech working at 16 kHz sampling frequency is supported. This requirement is defined in 3GPP technical specifications for IP Multimedia Subsystem
(IMS), Multimedia Messaging Service
(MMS) and Transparent end-to-end Packet-switched Streaming Service (PSS). In 3GPP specifications is AMR-WB format also used in 3GP container format.
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
ed speech coding
Speech coding
Speech coding is the application of data compression of digital audio signals containing speech. Speech coding uses speech-specific parameter estimation using audio signal processing techniques to model the speech signal, combined with generic data compression algorithms to represent the resulting...
standard developed based on Adaptive Multi-Rate
Adaptive Multi-Rate
The Adaptive Multi-Rate audio codec is a patented audio data compression scheme optimized for speech coding. AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM and UMTS...
encoding, using similar methodology as Algebraic Code Excited Linear Prediction (ACELP). AMR-WB provides improved speech quality due to a wider speech bandwidth of 50–7000 Hz compared to narrowband speech coders which in general are optimized for POTS
Plain old telephone service
Plain old telephone service is the voice-grade telephone service that remains the basic form of residential and small business service connection to the telephone network in many parts of the world....
wireline quality of 300–3400 Hz.
AMR-WB is codified as G.722.2, an ITU-T
ITU-T
The ITU Telecommunication Standardization Sector is one of the three sectors of the International Telecommunication Union ; it coordinates standards for telecommunications....
standard speech codec, formally known as Wideband coding of speech at around 16 kbit/s using Adaptive Multi-Rate Wideband (AMR-WB). G.722.2 AMR-WB is the same codec as the 3GPP
3GPP
The 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...
AMR-WB. The corresponding 3GPP specifications are TS 26.190 for the speech codec and TS 26.194 for the Voice Activity Detector.
A common file extension for AMR-WB file format is
.awb. There also exists another storage format for AMR-WB that is suitable for applications with more advanced demands on the storage format, like random access or synchronization with video. This format is the 3GPP-specified 3GP3GP
3GP is a multimedia container format defined by the Third Generation Partnership Project for 3G UMTS multimedia services. It is used on 3G mobile phones but can also be played on some 2G and 4G phones....
container format based on ISO base media file format
ISO base media file format
ISO base media file format defines a general structure for time-based multimedia files such as video and audio. It is used as the basis for other media file formats...
. 3GP also allows use of AMR-WB bit streams for stereo sound.
AMR modes
AMR-WB operates like AMRAdaptive Multi-Rate
The Adaptive Multi-Rate audio codec is a patented audio data compression scheme optimized for speech coding. AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM and UMTS...
with 9 different bit rates. The lowest bit rate providing excellent speech quality in a clean environment is 12.65 kbit/s. Higher bit rates are useful in background noise conditions and for music. Also lower bit rates of 6.60 and 8.85 kbit/s provide reasonable quality especially if compared to narrow band codecs.
All modes are sampled at 16 kHz (using 14 bit resolution) and processed at 12.8 kHz.
The bit rates are the following:
- Mandatory multi-rate configuration
- 6.60 kbit/s (used for circuit switched GSM and UMTS connections; should only be used temporarily during bad radio connections and is not considered wideband speech)
- 8.85 kbit/s (used for circuit switched GSM and UMTS connections; should only be used temporarily during bad radio connections and is not considered wideband speech; provides quality equal to G.722G.722G.722 is a ITU-T standard 7 kHz wideband speech codec operating at 48, 56 and 64 kbit/s. It was approved by ITU-T in November 1988. Technology of the codec is based on sub-band ADPCM ....
at 48 kbit/s for clean speech) - 12.65 kbit/s (main anchor bitrate; used for circuit switched GSM and UMTS connections; offers superior audio quality to AMR at and above this bit rate; provides quality equal to or better than G722 at 56 kbit/s for clean speech)
- Higher bitrates for speech in adverse background noise environments, combined speech and music, and multi-party conferencing.
- 14.25 kbit/s
- 15.85 kbit/s
- 18.25 kbit/s
- 19.85 kbit/s
- 23.05 kbit/s (not targeted for full-rate GSM channels)
- 23.85 kbit/s (provides quality equal to G.722 at 64 kbit/s for clean speech; not targeted for full-rate GSM channels)
Configurations for 3GPP
When used in mobile phone networks, there are three different configurations (combinations of bitrates) that may be used for voice channels:- Configuration A (Config-WB-Code 0): 6.6, 8.85, and 12.65 kbit/s (Mandatory multi-rate configuration)
- Configuration B (Config-WB-Code 2): 6.6, 8.85, 12.65, and 15.85 kbit/s
- Configuration C (Config-WB-Code 4): 6.6, 8.85, 12.65, and 23.85 kbit/s
This limitation was designed to simplify the negotiation of bitrate between the handset and the base station, thus vastly simplifying the implementation and testing. All other bitrates can still be used for other purposes in mobile phone networks, including multimedia messaging, streaming audio, etc.
Deployment
AMR-WB has been standardized by a mobile phone manufacturer consortium for future usage in networks such as UMTS. Its speech quality is high, but older networks will have to be upgraded to support a wide band codec.In October 2006, first AMR-WB tests were conducted in a deployed network by T-Mobile in Germany, in cooperation with Ericsson.
In 2007 end-to-end AMR-WB TrFO capable 3G & VoIP product line was commercially released by NSN
Nokia Siemens Networks
Nokia Siemens Networks is a global data networking and telecommunications equipment company headquartered in Espoo, Finland. It is a joint venture between Nokia of Finland and Siemens of Germany...
(M13.6 MSS
Network Switching Subsystem
Network switching subsystem is the component of a GSM system that carries out call switching and mobility management functions for mobile phones roaming on the network of base stations...
, U3C MGW
Media gateway
A Media gateway is a translation device or service that converts digital media streams between disparate telecommunications networks such as PSTN, SS7, Next Generation Networks or PBX...
). AMR-WB TFO support commercially released in 2008 (M14.2, U4.0). End-to-end TFO/TrFO negotiation and mid-call optimization (e.g. on handover
Handover
In cellular telecommunications, the term handover or handoff refers to the process of transferring an ongoing call or data session from one channel connected to the core network to another...
, CF
Call forwarding
Call forwarding , in telephony, is a feature on some telephone networks allowing an incoming call to a called party to be redirected to a third party. For example, the third party may be a mobile telephone, voicemail box or other telephone number where the desired called party is situated. It was...
or CT
Call transfer
A call transfer is a telecommunications mechanism that enables a user to relocate an existing call to another phone or attendant console by using the transfer button and dialing the required location. The transferred call is either announced or unannounced....
events) released in 2009 (M14.3, U4.1).
In late 2009, Orange (UK) announced that it would be introducing AMR-WB on its network in 2010.
In France Orange and SFR are using this codec on their 3G+ networks since the end of 2010 summer.
WIND Mobile in Canada launched HD Voice (AMR-WB) on its 3G+ network in February, 2011. WIND Mobile also announced that several handsets will support HD Voice (AMR-WB) in first half of 2011. WIND Mobile press release on HD voice First one being Alcatel Tribe.
Nokia
Nokia
Nokia Corporation is a Finnish multinational communications corporation that is headquartered in Keilaniemi, Espoo, a city neighbouring Finland's capital Helsinki...
developed VMR-WB
VMR-WB
Variable-Rate Multimode Wideband is a source-controlled variable-rate multimode codec designed for robust encoding/decoding of wideband/narrowband speech. The operation of VMR-WB is controlled by speech signal characteristics and by traffic condition of the network...
codec for CDMA2000
CDMA2000
CDMA2000 is a family of 3G mobile technology standards, which use CDMA channel access, to send voice, data, and signaling data between mobile phones and cell sites. The set of standards includes: CDMA2000 1X, CDMA2000 EV-DO Rev. 0, CDMA2000 EV-DO Rev. A, and CDMA2000 EV-DO Rev. B...
networks, which is fully interoperable with 3GPP AMR-WB.
AMR-WB is also widely adapted format in mobile handsets for tones.
The AMR wideband speech codec shall be supported in 3G
3G
3G or 3rd generation mobile telecommunications is a generation of standards for mobile phones and mobile telecommunication services fulfilling the International Mobile Telecommunications-2000 specifications by the International Telecommunication Union...
multimedia services when wideband speech working at 16 kHz sampling frequency is supported. This requirement is defined in 3GPP technical specifications for IP Multimedia Subsystem
IP Multimedia Subsystem
The IP Multimedia Subsystem or IP Multimedia Core Network Subsystem is an architectural framework for delivering Internet Protocol multimedia services. It was originally designed by the wireless standards body 3rd Generation Partnership Project , as a part of the vision for evolving mobile...
(IMS), Multimedia Messaging Service
Multimedia Messaging Service
Multimedia Messaging Service, or MMS, is a standard way to send messages that include multimedia content to and from mobile phones. It extends the core SMS capability that allowed exchange of text messages only up to 160 characters in length.The most popular use is to send photographs from...
(MMS) and Transparent end-to-end Packet-switched Streaming Service (PSS). In 3GPP specifications is AMR-WB format also used in 3GP container format.
See also
- Adaptive Multi-RateAdaptive Multi-RateThe Adaptive Multi-Rate audio codec is a patented audio data compression scheme optimized for speech coding. AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM and UMTS...
(AMR) - Extended Adaptive Multi-Rate - Wideband (AMR-WB+)
- Half RateHalf RateHalf Rate is a speech coding system for GSM, developed in the early 1990s.Since the codec, operating at 5.6 kbit/s, requires half the bandwidth of the Full Rate codec, network capacity for voice traffic is doubled, at the expense of audio quality. It is recommended to use this codec when the...
- Full RateFull RateFull Rate or FR or GSM-FR or GSM 06.10 was the first digital speech coding standard used in the GSM digital mobile phone system. The bit rate of the codec is 13 kbit/s, or 1.625 bits/audio sample...
- Enhanced Full RateEnhanced Full RateEnhanced Full Rate or EFR or GSM-EFR or GSM 06.60 is a speech coding standard that was developed in order to improve the quite poor quality of GSM-Full Rate codec. Working at 12.2 kbit/s the EFR provides wirelike quality in any noise free and background noise conditions...
(EFR) - G.722G.722G.722 is a ITU-T standard 7 kHz wideband speech codec operating at 48, 56 and 64 kbit/s. It was approved by ITU-T in November 1988. Technology of the codec is based on sub-band ADPCM ....
- G.722.1G.722.1G.722.1 is a licensed royalty-free ITU-T standard audio codec providing high quality, moderate bit rate wideband G.722.1 is a licensed royalty-free ITU-T standard audio codec providing high quality, moderate bit rate (24 and 32 kbit/s) wideband G.722.1 is a licensed royalty-free ITU-T standard...
- 3GP3GP3GP is a multimedia container format defined by the Third Generation Partnership Project for 3G UMTS multimedia services. It is used on 3G mobile phones but can also be played on some 2G and 4G phones....
- Comparison of audio codecsComparison of audio codecsThe following tables compare general and technical information for a variety of audio formats and audio compression formats. For listening tests comparing the perceived audio quality of audio formats and codecs, see the article Codec listening test....
- RTP audio video profile
External links
- ITU-T Recommendation G.722.2; (AMR-WB)- technical specification
- Adaptive Multi-Rate - Wideband (AMR-WB) speech codec; Transcoding functions; 3GPP TS 26.190 - 3GPP technical specification
- Adaptive Multi-Rate - Wideband (AMR-WB) speech codec; Voice Activity Detector (VAD); 3GPP TS 26.194 - 3GPP technical specification
- Adaptive Multi-Rate - Wideband (AMR-WB) speech codec; General description; 3GPP TS 26.171 - 3GPP technical specification
- 3GPP codecs specifications; 3G and beyond / GSM, 26 series
- RFC 4867 - RTP Payload Format and File Storage Format for the Adaptive Multi-Rate (AMR) and Adaptive Multi-Rate Wideband (AMR-WB) Audio Codecs
- RFC 4281 - The Codecs Parameter for "Bucket" Media Types
- Deep Inside the Network, Episode 2: AMR-WB - Skype-like Audio Quality for Mobile Networks
- Wideband Speech Coding Standards and Applications
- 3GPP - Technical Specification Group Services and System Aspects
- ITU-T Implementors' Guide for G.722.2