Abstract: The video performance of the Median wireless asynchronous transfer mode (WATM) system is evaluated for a range of application scenarios using the H.263 video codec and a novel packetisation and acknowledgement scheme. The video resolutions and system parameters used are summarised in Tables 1 and 2. The required channel signal-to-noise ratio for near-unimpaired video quality is about 16dB over the dispersive worst-case channel used. 1 System Overview The proposed wireless LAN system's schematic is shown in Figure 1, which supports videophone calls. The video signal is compressed using the H.263 video compression standard . The H.263 standard achieves very high compression ratio, however the resulting bitstream is extremely sensitive tochannel errors. This sensitivity tochannel errors is not a serious problem over benign wireline-based Gaussian channels, but it is an impediment, when used over wireless networks. There have been several solutions suggested in the literature for overcoming this using Automatic Repeat Request (ARQ) , dual-level coding  and the use of a feedback channel . A range of further robust video schemes were proposed in -citecherriman96-journal
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