MPEG-2 VIDEO SERVICES FOR WIRELESS ATM NETWORKS

Audio-visual and other multimedia services are seen as an important so urce of traffic for future telecommunications networks, including wire less networks. In this paper, we examine the impact of the properties of a 50 Mb/s asynchronous transfer mode (ATM)-based wireless local-are a network (WLAN) on moving picture experts group phase 2 (MPEG 2) comp ressed video traffic, with emphasis on the network's error characteris tics. The paper includes a description of the WLAN system used and its loss characteristics, a brief discussion of relevant aspects of the M PEG 2 standards and the associated error resilience techniques for min imizing the effect of transmission errors, and a description of the me thod by which the video data is organized for transmission on the netw ork. We show results on the effect of cell loss due to transmission er rors on the quality of the decoded video at the receiver, and demonstr ate how error resilience techniques in both the systems and video laye rs of MPEG 2 can be used to improve the quality of service. Situations where up to 1% of the data is lost due to network transmission errors are examined. Most important among the findings are that error resili ence experiments that do not take into account the effect of the MPEG 2 systems layer will tend to significantly overestimate the quality of received video, and that the error resilience techniques provided wit hin the MPEG 2 standard are not sufficient to provide acceptable quali ty with acceptable overheads, but that this quality can be significant ly increased by the addition of a small number of simple techniques.