DRB and DCCB: Efficient and Robust Dynamic Broadcast for Ad Hoc and Sensor Networks

Deterministic, timer-based broadcast schemes not only guarantee full reachability over an idealistic lossless MAC layer, they also stand out for their robustness against node failure as well as more general changes in the network topology. This paper proposes the first broadcast schemes in this class which provably perform within a factor of the optimal efficiency (in terms of number of rebroadcasts). To the best of our knowledge no other deterministic timer-based scheme possesses this property. NS-2 simulations employing the 802.11b MAC protocol confirm our analysis. The factor can be estimated to be quite small. Novel to the proposed schemes is also their hybrid backbone consisting of a given, static dominating set (DS) and a dynamically computed set of connecting nodes. As an additional contribution, this paper studies the trade-off of timer settings (and thus latency) against the number of rebroadcasts, as well as the robustness of the proposed algorithms. To the best of our knowledge, no prior study of these issues in the context of broadcast exists.