AASC: adaptive avoid second-collision backoff algorithm for multihop wireless sensor networks

Multihop is the main communication style for wireless sensor networks. MAC protocol has great impact on performance of network. CSMA-CA´s backoff algorithm specification in the IEEE 802.15.4 standard cannot adapt to dynamic network and multihop communication. This paper proposes a strategy that relays data should have priority. This strategy guarantees that remote node´s packets are transmitted reliably to destination node, whether network is burst flow or non-burst flow. A new backoff algorithm that can adapt to flow and avoid second-collision is proposed and analyzed in this paper. The paper models the networking using the theory of discrete tune Markov chains. Numerical results and OPNET simulation show that the new algorithm can adapt to burst flow better and produces throughput improvements, whether the number of node is large or small. Simulation results also show that the new algorithm relays more remote node´s packets to destination node and saves energy through reducing retransmission in multihop networks