A token-based greedy chain scheduling algorithm (T-GCSA) for situation aware wireless LANs

Proposes a media access control (MAC) protocol for situation aware, long range wireless local area networks (LANs) consisting of highly mobile nodes. We choose to schedule node transmissions instead of using contention-based protocols for accessing the channel. This approach is attractive for improving the performance of wireless LANs with long propagation delays. An example of such wireless LANs is a set of planes in a range of hundred miles with radio communications. The problem with contention-based MAC protocols is that each node has to wait for the maximum propagation delay (from one end of the coverage area to the other), before it can decide whether the channel is free or the previous node had no packet to transmit. We propose an "educated" token-based adaptive algorithm that schedules individual node transmissions in a way that minimizes the total propagation delay for each round, based on global location information (obtained, for example, using GPS). This way, nodes that are near one another are also adjacent in the schedule, and therefore have to wait significantly less time before they can decide whether it\´s safe to transmit or not.