Using Number of Retransmissions to improve Routing in Ad-hoc Networks

Abstract—In this paper, we analyze the effectiveness of usual metrics and Quality of Service (QoS) methods used to improve routing in wireless networks, when considering the erroneous nature of radio links. We first analyze an additive metric based on Bit Error Rate (BER) and we propose a new metric similar to hop-count metric where retransmissions are accurately taken into account. With this number of retransmissions-based metric, the distance between two adjacent nodes will not be 1, but 1 plus the cost of retransmissions required on the link. Our approach is a light and immediate way to evaluate link quality. It does not imply additional network overhead and costly computation. To test the efficiency of this new metric, we have implemented it into the well-known Optimized Link State Routing protocol. Realistic simulation results show that this metric outperforms traditional metrics like the ones based on delay, BER or Expected Transmission Count.