Optimization approach for throughput analysis of multi-hop wireless networks

A critical performance metric of multi-hop wireless networks is the end-to-end throughput of a multi-hop wireless path. When the packets of a traffic flow originating from a source node are relayed by intermediate nodes (relay nodes), competition between the nodes on the multi-hop routing path incurs transmission delays from the carrier sensing mechanism, as well as packet drops and retransmissions due to hidden terminals. Owing to this complicated interaction between nodes, problems in the throughput performance analysis of multi-hop networks have not been fully resolved. In this paper, we propose an optimization approach to compute the throughput at each individual link in addition to the end-to-end throughput in an IEEE 802.11 DCF-based multi-hop wireless network. To this end, we first analyze a multi-hop chain topology with a single flow by taking into account transmission collisions from hidden terminals, and then formulate the optimization problem to obtain the end-to-end throughput performance of multi-hop networks. Through extensive ns-2 simulations, we then show that the proposed approach accurately predicts the throughput performance obtained by the simulations, within a discrepancy of less than 10-12 % in the worst case scenario under a variety of chain and cross topologies.