Game-theoretical Relay Selection strategy for geographic routing in Multi-hop WSNs

This contribution proposes and investigates a random access Medium Access Control (MAC) - Relay Selection Mechanism - for cluster-based geographic routing in Multi-hop Wireless Sensor Networks (WSNs). The intertwined MAC and network routing solution is derived in a cross-layer approach. The game-theoretical relay selection strategy (random multiple access) relies on well-known descending pricing auctions also known as "Dutch Auctions". In particular, successive rounds of Dutch auctions are employed to deal with contention avoidance and contention resolution stages of the non-cooperative games between source and relay nodes. If a non-empty auction round has no winner (due to collision), the source starts a new round with a signaling packet containing an indication of collision. Consequently, at each round relay candidates are able to infer on their location relative to other potential relays, based on which they can choose to drop out or continue their bidding. The strategy, which is fully distributed and eliminates the need for the source to know the number of potential relays a priori, proves very efficient, approaching the performance of an ideal scheduled-based Random Selection Algorithm (RSA). The performance of our previously proposed cluster-based geographic routing employing this RSA is investigated using an event-driven network simulation, in a scenario with a topological dead-end hole. The results indicate that the combined techniques can retain a substantial portion of the Packet Delivery Success Ratio (PDSR) associated with a system with perfect relay selection.