Only the short die old: route optimization in MANETs by dynamic subconnection shrinking

• Authors: Zeki Bilgin;Bilal Khan;Ala Al-Fuqaha
• Venue: Proceedings of the 6th International Wireless Communications and Mobile Computing Conference
• Year: 2010

In reactive routing protocols, active routes for multihop connections retain their topological structure in spite of node movement over time. Unfortunately, node movements may make the connection route sub-optimal in terms of hop length, thereby resulting in unnecessarily high end-to-end delays, energy consumption and channel contention. In AODV, for example, a connection route is recomputed only if one of its constituent links suffers catastrophic failure, at which point global route discovery attempts repair, and after which the topological structure of the connection again returns to near-optimality. In this paper, we propose an extension to AODV that performs periodic subconnection shrinking of the topological substructure within each connection. We show that this not only reduces the average end-to-end connection length, but also increases the mean time between catastrophic link failures of the connection's constituent links, thereby reducing the number of repair-related global route discoveries experienced. The control traffic needed to operate our scheme can be amortized against the reduction in repair-related global route discovery traffic. Through ns2 simulations, we show that our dynamic subconnection shrinking scheme manifests connections that, on average, have (i) shorter hop length, (ii) higher packet delivery fraction; moreover, this extension operates using less control traffic than standard AODV. We demonstrate that these conclusions continue to hold scalably over a wide range of operating regimes.