A novel scheme for streaming multimedia to personal wireless handheld devices

Delivering streaming video over wireless is an important component of many interactive multimedia applications running on personal wireless handheld devices. Such personal devices have to be inexpensive, compact, and lightweight. Wireless channels have a high channel bit error rate and limited bandwidth. Delay variation of packets due to network congestion and the high bit error rate degrades the quality of video at the handheld device. Multimedia application use a buffer at the handheld device smooth out the delay variation and improve the quality of streaming video. However, the buffer size has to be kept small in order to reduce the size, weight and power consumption of handheld devices. In this paper, we propose a novel selective retransmission scheme for multimedia transmission over wireless networks. Our scheme is based on retransmission of only the most important information in a video in order to achieve a high quality of video. Our objective is to develop a simple cost effective scheme which offers an acceptable video quality over a noisy wireless channel using a small buffer size at the handheld device. We have developed an analytical model to determine the networking requirements, video quality as a function of video compression parameters and network error conditions, and optimally dimension the buffer at the handheld device. Index Terms--Wireless handheld device, Streaming video, Personal Digital Assistant, Handheld device design.