T-MAH: A Token Passing MAC protocol for Ad Hoc Networks

The Token Passing MAC protocol for Ad Hoc networks (T-MAH), discussed in this paper, is a distributed medium access protocol designed for wireless multi-hop networks. With T-MAH access scheme the network is organized in clusters (called Token Groups) with a Token Group Head as the leader of the group. In each single cluster is used a token based technique, i.e. each node in the cluster is allowed to transmit the user data only after has received a particular packet (called token) and the time slot has not been expired. The combination of a controlled MAC protocol and a hierarchical network division, reduces the number of the error due to packet collision and permits a good channel reutilization.