Improving image and video transmission quality over ATM with foveal prioritization and priority dithering

Abstract Several characteristics of the asynchronous transfer mode (ATM) protocol are making it increasingly popular with designers of networked multimedia systems. However, the main drawback to ATM-based switching is the possibility of information loss with congestion. In this paper, we address this issue; we demonstrate that with intelligent, fovea-driven priority assignment of image data, we can reduce the negative impact of information loss over ATM networks. ATM standards allow a single bit to indicate high or low packet priority. To reduce the effect of this restriction we introduce the concept of priority dithering. Network multimedia multicast scenarios over heterogeneous link capacities where foveal prioritization would be of benefit are described. Network simulation results of this method are included which demonstrate the advantages of priority dithered foveal prioritization over traditional methods.