A distributed mutual exclusion algorithm for mobile ad-hoc networks

A distributed mutual exclusion algorithm based on token exchange and well suited for mobile ad-hoc networks is presented along with a simulation study. The algorithm is based onto a dynamic logical ring and combines the best from the two families of token based algorithms (i.e., tokenasking and circulating token) in order to get a number of messages exchanged per CS access (the main performance index for such algorithms) that tends to optimal values under heavy request load (i.e., two application messages each CS access). We present a simulation study that (i) confirms this optimality and (ii) shows that, in a mobile ad-hoc network, an effective reduction in the number of hops per application message can be achieved by using a specific policy to build on-the-fly the logical ring.