Performance Analysis of Header Compression Schemes in Heterogeneous Wireless Multi–Hop Networks

Wireless multi–hop networks are becoming more popular and the demand<br>for multimedia services in these networks rises with the number of<br>their implementations. Header compression schemes that compress the<br>IP/UDP/RTP headers to save bandwidth for multimedia streams were<br>typically evaluated only for individual links, not taking into account<br>the savings that can be achieved using header compression over a<br>complete path. In this paper, we evaluate the performance of three<br>categories of header compression schemes: (i) delta coding, (ii)<br>framed delta coding, and (iii) framed referential coding. We evaluate<br>the performance for these schemes on reliable and unreliable links.<br>We then extend our evaluations to several links constituting a path.<br>As nodes in multi–hop ad-hoc and mesh networks may differ with respect<br>to their capabilities, we assume in our evaluation that (forwarding)<br>nodes may not be able or choose not to perform header compression.<br>We find that the framed referential header compression scheme is<br>the most suitable scheme in case that no or long-delay feedback channels<br>exist. We additionally compare the packet drop savings due to header<br>compression and the combined savings of compression and drops. We<br>again find that the framed referential coding scheme exhibits good<br>performance that can lead to significant header compression and packet<br>drop savings for reasonable bit error rates.