QoS-directed error control of video multicast in wireless networks

In this paper we present a QoS-directed error control scheme (QDEC) for video multicast in wireless networks. In order to provide multimedia services to mobile users, it is necessary to have not only sufficient bandwidth, but also effective control over wireless channel errors, which are characterized as bursty and location-dependent. The QDEC scheme includes: (1) a video QoS differentiation specification to direct the error control; and (2) three error control algorithms with corresponding channel error conditions under which the algorithms should be chosen. Through analysis and simulation, we show that QDEC has the following key properties: (1) high error recovery rate for QoS-essential video frames, (2) excellent scalability, (3) high transmission efficiency, and (4) no QoS degradation for receivers who observe no channel errors