Press Release |
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International Telecommunication Union
For immediate release |
Telephone: +41 22 730 6039
Fax: +41 22 730 5939
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New Wideband Speech Coding Standard Set by
ITU
Speech Quality for Wireless and Wireline
Expected to Improve
Geneva, 31 January 2002 —
The ITU has approved a new Standard for high-quality digital wideband speech
encoding that will bring significant improvements in terms of interoperability,
easier implementation, and improved quality, for wideband voice applications and
services across a wide range of communication systems and platforms.
Several important applications are envisaged for the standard.
These include: Voice over IP (VoIP) and the Internet, third generation mobile
communications, PSTN high-quality audio-conferencing and business applications
(both in point-to-point and multi-point situations), streaming audio and speech,
ISDN wideband telephony, and ISDN video telephony and video-conferencing.
The standard, known as Recommendation G.722.2, is also
referred to as the Adaptive Multi-Rate Wideband (AMR-WB) codec. It has been
selected by 3GPP (Third Generation Partnership Project) as the Wideband codec
for GSM and 3rd generation wireless W-CDMA applications. This marks the first
time that both wireless and wireline services may be able to adopt the same
codec. Pierre-Andre Probst, Chairman of ITU-T Study Group 16 notes, "The
AMR-WB codec is a breakthrough in speech quality. The fact that the same codec
has been adopted means that interoperation between 3G and fixed IP networks will
be that much easier".
Wideband speech coding, using an audio band of 50-7 000
Hz, offers major subjective improvements in speech quality compared to
traditional narrowband telephone speech (200-3 400 Hz). A bandwidth of
50 to 7 000 Hz improves the intelligibility and naturalness of
speech, adds a feeling of transparent communication and eases speaker
recognition. The low-frequency enhancement from 50 to 200 Hz contributes to
increased naturalness, presence and comfort while the high-frequency extension
from 3 400 to 7 000 Hz provides improved intelligibility.
Rosario Drogo de Iacovo, Chairman of the subcommittee
responsible for the work (ITU-T Study Group 16) adds, "experts from around
the world have collaborated in the definition, selection and testing of this new
codec. It is truly state-of-the-art". Simão Campos-Neto, Chairman of ITU-T
Working Party 3/16 (Media Coding) notes, "The adoption of the same
algorithm by both Standards Organizations is the result of a closely coordinated
effort. We are proud to offer a single standardized solution that can be used
across several industries.
Further Technical Information for Editors:
The G.722.2 algorithm utilizes the Algebraic Code Excited
Linear Prediction (ACELP) technology developed by VoiceAge Corp. in
collaboration with Nokia, with additional novel features for improving the
quality of wideband signals. G.722.2 is a multi-rate codec consisting of nine
modes with bit rates of 23.85, 23.05, 19.85, 18.25, 15.85, 14.25, 12.65, 8.85
and 6.6 kbit/s. It also includes an integrated Voice Activity Detector (VAD) in
conjunction with Discontinuous Transmission (DTX) and Comfort Noise Generation (CNG)
for efficient low bit rate source controlled operation in background noise. The
total computational complexity of the codec is estimated at less than 40 MIPS
with a data RAM requirement of 6.5 kWords and total ROM requirement below 16
kWords. The standard is described in bit-exact C-code using a set of fixed-point
basic operators.
For more information please contact:
Mike Buckley
PR Officer,
ITU-T Study Group 16
Phone: +44-1457-877718
e-mail: mikebuckley@44comms.com |
Rosario Drogo De Iacovo
Rapporteur for Question 07/16
Technology Integration & Research
TILAB S.p.A.
Phone: +39 011 228 6221
Fax: +39 011 228 7056
e-mail: rosario.drogodeiacovo@tilab.com |
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