Performance of Packet Header Compression and Context Replication in Wireless/Mobile Systems

MIPv6 as proposed in RFC3775 can be implemented in IPv6 as an extension header. Therefore, using standard RObust Header Compression (ROHC) [1] protocol, header compression can be applied for wireless environments with high bit error rate and long round trip delays. For wireless/mobile systems operating in a dynamic wireless environment, where the channel quality is highly variable, an adaptive compression method is introduce, which also performs superior to the current static ROHC techniques. Our proposal is based on adjustment of sliding window width (SWW) of Window-based Least Significant Bit (W-LSB) encoding algorithm, without the need to measure PLR, BER, or introduce additional protocol messages. We evaluate the performance of standard O-mode ROHC as prescribed in RFC 3095 and compare with the adaptive adjustment scheme through simulations. Furthermore, this paper investigates context replication for header compression based on RFC 4164. It is shown that the former approach improves channel utilization at a comparable or improved decompression failure rate, and the latter approach results in improved channel utilization when short messages are involved in mobile communications.