Alleviating intra-flow interference by inter-arrival based packet dropping in wireless multi-hop networks

Abstract

In CSMA-based wireless multi-hop networks, consecutive packets on a single multi-hop path interfere with each other, causing hidden/exposed terminal problems and frequent contention. This phenomenon is called intra-flow interference and is considered as one of the principal factors degrading the throughput performance, since it increases the number of collisions as well as backoff intervals. Here, we propose a probabilistic packet dropping algorithm that mitigates the intra-flow interference on wireless multi-hop networks. In the proposed algorithm, a wireless node classifies all flows into several 1-hop forwarding domains, which are determined by the next relay node. For this classification, each node regards the flows that will pass the same 1-hop neighbor as ones belonging to the same forwarding domain. Each node probabilistically drops incoming packets if the inter-arrival time of incoming packets belonging to the same forwarding domain is so short as to make intra-flow interference. Through extensive simulation studies, we show that the proposed algorithm effectively reduce the intra-flow interference, and increases the overall throughput as well as fairness on wireless multi-hop networks.