Due to bandwidth constraints on the wireless link in an IP network, it is useful to compress the headers so as to maximize the utilization of the link. There exist header compression algorithms that make use of the similarity in consecutive headers in a packet flow to compress these headers.First, we introduce the traditional header compression: VJHC, IPHC, CRTP and ROHC. Second, we introduce a new header compression scheme, a user-based frequency-dependent IP header compression (FBHC) architecture that makes use of the similarity in consecutive flows from or to a given mobile terminal to compress these headers. We also introduce architecture to distribute the information necessary for our header compression scheme to the network entities participating in the header compression by means of context transfer. Our scheme is complementary and the benefits are additional to the traditional approach to header compression. Last, there is a succession of wireless links in an ad hoc networks,In these scenarios, a link based compression might be costly, as each hop has to decompress the IP headers and re-compress them for further forwarding. We present here a technique to alleviate this issue and provide multi-hop compression. The idea is to split the compression according to the network part of the header, and the transport part of the header. We introduce a signaling that allows the nodes participating in the compression to establish the compression end-to-end. The multi-hop compression might be especially beneficial in sensor networks, where typically payload is small and the cost of transmitting any bit is quite high.