An efficient multiplex architecture for mobile MPEG-4 systems

This gaper describes a multiplex architecture for mobile multimedia applications which has been considered as the underlying multiplex system in the MPEG-4 standardization effort (MPEG-4: Coding of audio-visual objects, standardization project of the ISO/IEC JTC1/SC29/WG11). Multimedia information consists of several different kinds of information which differ widely in their requirements on Quality of Service (QoS). The generic data services in today's mobile networks are not designed to comply with these QoS requirements. On the other hand, future object-based multimedia systems (e.g. MPEG-4) will use a multitude of simultaneous data streams. Many of these will have similar requirements on transmission. The proposed multiplexing architecture consists of two layers. One layer serves to bundle elementary data streams of similar QoS requirements, resulting in a small number of data streams with differing QoS requirements. The other layer serves to provide appropriate error protection for each of these streams and to form a single data stream which can be transmitted over an error prone link. Thus multiplexing overhead is minimized while error protection is adapted to the requirements of the individual elementary streams. It is argued that the lower layers dealing with protection and the error-resilient multiplex of the protected streams should be included in the network in order to avoid the problems of end-to-end error control. The system described can thus help to obtain highly efficient multimedia communication with future mobile networks. (C) 1999 Elsevier Science B.V. All rights reserved.