3G-324M is the 3GPP umbrella protocol for

video telephony Videotelephony, also known as videoconferencing and video teleconferencing, is the two-way or multipoint reception and transmission of audio signal, audio and video signals by people in different locations for Real-time, real time communication. ...

in 3G mobile networks. The 3G-324M protocol operates over an established circuit switched connection between two communicating peers. 3G-324M is an umbrella specification to enable conversational multimedia communication over Circuit Switched (CS) networks and has been adopted by the 3GPP. 3G-324M is based on the

ITU-T The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Commu ...

H.324 H.324 is an ITU-T recommendation for voice, video and data transmission over regular analog phone lines. It uses a regular 33,600 bit/s modem for transmission, the H.263 codec for video encoding and G.723.1 for audio. H.324 standard is formally ...

specification for multimedia conferencing over

Circuit switched Circuit switching is a method of implementing a telecommunications network in which two network nodes establish a dedicated communications channel ( circuit) through the network before the nodes may communicate. The circuit guarantees the full ...

networks.IMTC Press Coverage
, International Multimedia Telecommunications Consortium (IMTC), April 1, 2001 to November 16, 2004.Orr, Eli
News & Analysis: Understanding The 3G-324M Spec
EETimes.com website. January 21, 2003. 3G-324M is composed of the following sub-protocols: * ITU-T H.245 for call control * ITU-T H.223 for bit streams to data packets multiplexer/demultiplexer * ITU-T H.223 Annex A and B for error handling of low and medium BER detection, correction and concealment * ITU-T

with Annexes A and C for operating in wireless environment The 3G-324M specification using the

network allows delay sensitive conversational multimedia services such as: *

Videoconferencing Videotelephony, also known as videoconferencing and video teleconferencing, is the two-way or multipoint reception and transmission of audio signal, audio and video signals by people in different locations for Real-time, real time communication. ...

for personal and business use * Multimedia entertainment services * Telemedicine * Surveillance * Live Video Broadcasting– Cable TV On-the-Go *

Video-on-demand Video on demand (VOD) is a media distribution system that allows users to access videos without a traditional video playback device and the constraints of a typical static broadcasting schedule. In the 20th century, broadcasting in the form of o ...

(movies, news clips) 3G-324M is agnostic to the actual

network that uses it. It can run as easily over

UMTS The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...

as well as

TD-SCDMA The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the Inte ...

networks. 3G-324M operating over a circuit switched channel between two communication peers guarantees the fixed-delay quality of service for multimedia communications. Combining

3G-324M services with packet-based SIP services such as presence can leverage the strength of both networks to enable new types of differentiated and innovative mobile 3G services.

Codecs

Audio Codec * GSM

Adaptive Multi-Rate The Adaptive Multi-Rate (AMR, AMR-NB or GSM-AMR) audio codec is an audio compression format optimized for speech coding. AMR speech codec consists of a multi-rate narrowband speech codec that encodes narrowband (200–3400 Hz) signals at var ...

, mandatory *

AMR-WB Adaptive Multi-Rate Wideband (AMR-WB) is a patented wideband speech audio coding standard developed based on Adaptive Multi-Rate encoding, using a similar methodology to algebraic code-excited linear prediction (ACELP). AMR-WB provides improved ...

(G.722.2), optional * ITU-T

G.723.1 G.723.1 is an audio codec for voice that compresses voice audio in frames. An algorithmic look-ahead of duration means that total algorithmic delay is . Its official name is ''Dual rate speech coder for multimedia communications transmitting at ...

, optional Video Codec * ITU-T H.263, mandatory * ITU-T

H.261 H.261 is an ITU-T video compression standard, first ratified in November 1988. It is the first member of the H.26x family of video coding standards in the domain of the ITU-T Study Group 16 Video Coding Experts Group (VCEG, then Specialists Gro ...

, optional *

MPEG-4 part 2 MPEG-4 Part 2, MPEG-4 Visual (formally ISO/IEC 14496-2) is a video compression format developed by the Moving Picture Experts Group (MPEG). It belongs to the MPEG-4 ISO/IEC standards. It uses block-wise motion compensation and a discrete cosine tr ...

simple profile 1 level 0, optional * ITU-T

H.264 Advanced Video Coding (AVC), also referred to as H.264 or MPEG-4 Part 10, is a video compression standard based on block-oriented, motion-compensated coding. It is by far the most commonly used format for the recording, compression, and distr ...

, optional

References

External links

3GPP TS 26.111 - Codec for circuit switched multimedia telephony service; Modifications to H.324

IMTC 3G-324M AG
- Interoperability and testing activity group covering the 3G-324M and H.324 protocol
3G-324M on Windows Mobile
- An interesting article on the integration of 3G-324M into a Windows Mobile operating system
Understanding the 3G-324M Spec
{{Webarchive, url=https://web.archive.org/web/20080517183539/http://www.commsdesign.com/design_corner/OEG20030121S0009 , date=2008-05-17 - A good explanation on the specification of 3G-324M Videotelephony Application layer protocols