A round robin medium access protocol for MANs

Abstract

In this paper, we introduce a new protocol, which we refer to as the R²-Net protocol. The objective of this proposal is to introduce an access protocol that is based on allowing active nodes to share the bandwidth in a round robin manner. By following such an approach, it is shown that the protocol does not suffer from the problems inherent in the DQDB protocol. The implementation of the round robin principle requires nodes to keep track of the number of active downstream nodes. In addition, and in order to overcome the adverse effects of the nonzero propagation delay, the total number of segments that must be transmitted by downstream nodes is also recorded. The protocol has several attractive features such as fairness in bandwidth distribution among nodes, a speedy convergence to such a distribution, a low access delay, and more importantly, insensitivity of such measures to node activity patterns. A simulation study has shown the satisfaction of such properties. Since priority is an important feature of every protocol, we also show how the R²-Net protocol can be generalized to implement priority.