Real-time transmission of multilayer video over ATM networks

Abstract

With today's network technology, our expectations for high performance networked multimedia applications are increasing. However, no complete solution as yet exists for providing integrated services to networked multimedia systems. The difficulty lies in the nature of the multimedia data, basically video and audio, which is difficult to store and transmit. The coded video is sensitive to delay, delay variation, bit errors and losses. Our research focuses on the transmission of multilayer real-time video traffic over ATM (Asynchronous Transfer Mode) networks. This issue covers several aspects of ATM and multimedia networking such as video application layer, ATM adaptation layers, traffic and buffer management. The main assumption in this research is that the real-time video traffic is content based coded and consists of several video objects. A single video source with various video objects introduces the need for multiple priorities. We propose a multipriority traffic management model for ATM networks that includes a new priority cell mapping algorithm, a new priority based bandwidth allocation approach, a new adaptation layer definition, and a new multipriority buffer access control algorithm. Using multipriority traffic will complicate the traffic management, the buffer management and the work of the ATM adaptation layers. On the other hand, by allowing the network to have several priority layers during a connection, the overall quality for real-time video will be increased. To our knowledge, no method exists for managing a single connection for multipriority video traffic over ATM networks. Our model is new and addresses the essential transmission requirements of near future multipriority video coding systems over broadband networks.