Opportunistic Cooperative Routing in Multi-Radio Multi-Channel Wireless Sensor Networks

Interference and unreliability of wireless transmissions limit the throughput of wireless sensor networks. Multi-radio multi-channel technology shows its prospect to significantly improve the network capacity by reducing co-channel interference, and opportunistic cooperative offers a great chance to cope with the unreliability of wireless transmissions. In this paper, we present a multi-radio multi-channel opportunistic cooperative routing (MMOCR) protocol to improve the network throughput. Different from the traditional routing protocols, MMOCR chooses some opportunistic forwarding nodes on the channel with the least interference. The cumulative interference strength (CIS) is proposed to quantify different channel conditions, and a receiver-oriented mechanism to avoid the deafness problem. Packets are collaborative forwarded in accordance with the priorities of forwarding candidate nodes and a slotted acknowledgement is used to guarantee packet delivery and reduce duplication. We finally compare MMOCR with traditional opportunistic routing and deterministic routing protocols, the results show the proposed routing strategy achieves a better performance, especially in terms of the network throughput and packet delivery radio.