Study Of Adaptive Selection Unicast Alogrithm Combining Routing With Network Coding In Wireless Ad Hoc Networks

Network coding is a new type of data transmission mode, which can increasenetwork throughput, balance network load and improve the utilization rate of bandwidthwhen is used to transmit packets in wireless Ad hoc networks. However, whenconsidering the changing factors, including traffic arrival time interval, link reliabilityand network topology, present unicast schemes based on network coding can’t be wellapplied in wireless Ad hoc networks. Therefore, nodes should jointly consider the threeabove factors and adaptively select proper transmission mode from traditional routingand network coding according to the variation of above factors.A in-depth study on routing and network coding mode’s end-to-end delay thattakes up the channel in wireless Ad hoc networks with butterfly topology has been madeand their computation formula have been derived. A comparison of the above twounicast modes’ end-to-end delay has also been made and their suitable applicationconditions are given respectively by further theoretical analysis. On this basis, the paperproposes an adaptive selection unicast algorithm, which combines routing with networkcoding(ASRNC). The algorithm jointly considers traffic busy degree, bit error rate,packet length, as well as nodes number to minimize the end-to-end delay. The algorithmenables key nodes to adaptively select the low delay unicast mode from routing andnetwork coding modes. Theoretical analysis is given in the paper. Therefore, thealgorithm makes effective use of routing and network coding mode’s advantagesrespectively and gives a better satisfaction of traffic demands. From simulation results,we can observe that compared to the present unicast schemes, the ASRNC algorithmdecreases the end-to-end delay and improves the network performance with respect tounicast traffics.