Multi-stream video transport over DiffServ wireless LANS

This paper presents a new transport scheme for embedded video streams over wireless local area networks. It introduces a differentiated service (DiffServ) solution for video streaming over mobile ad hoc networks (MANETs). It employs the concept of single-application multiple stream (SAMS) that can effectively take the advantages of both DiffServ network and multi-layer or progressive source coding techniques. The approach is to preferentially improve the transport quality of important data substreams under the of a fixed network throughput. The 3D-SPIHT subband video coder is used in generating embedded source data streams. This video coder features high compression efficiency. It produces fully embedded bitstreams which can be easily segmented into multiple data streams with different QoS characteristics. In wireless network, a class based queuing (CBQ) mechanism is implemented to provide DiffServ for these different data streams. The integrated source coding and networking system prioritizes the layers for lower resolutions, so that they will experience less delay or packet loss in case of congestion or link breakage. Simulations have been conducted on the network simulator (ns-2), and significant improvements over traditional wireless LAN transport schemes have been observed.