Handoff Assigned Multiple Access (HAMA): A New Multiple Access Protocol for Computer Communication Networks

The Handoff Assigned Multiple Access (HAMA) protocol has been designed to meet the performane requirements of the Tactical Intra-task Force Network, a hypothetical mobile Navy broadcast radio network. This packet switched network will facilitate the transmission and reception of target track data and various command and control messages between Navy platforms (ships) in a dynamic, tactical environment. The unique characteristics and requirement of the TACNET resulted in the development of the HAMA multiple access protocol. The protocol is based on Time Division Multiple Access, in which the communication channel is divided into time frames, which are further subdivided into time slots. Each network node (ship) is assigned a particular slot, with exactly one slot for each node. With HAMA each node is allowed to handoff its slot to other network nodes. Thus, a node which has no use for its slot can dynamically hand it off to another node which does need it. Analysis of the protocol, both analytical and by simulation, indicates it performs remarkably well, much better than Time Division Multiple Access (TDMA) even at very high throughputs. Of particular importance to military networks, the analysis results indicate the protocol is very robust, and performs well under a variety of tactical conditions.