Impact of Interference and Medium Access Control on Flow Allocation in Multi-Hop Wireless Networks

The interaction between MAC protocols and interference in wireless multi-hop networks introduces extra constraints on achievable flow rates. In this paper, we formulate an optimization problem which considers jointly interference at the physical layer, MAC protocols, and end-to-end flow rate allocation. We then propose an interference-aware flow allocation algorithm to achieve optimal and fair flow rates in multi-hop wireless networks. In our study, the interference is characterized by the interference factor R, i.e., the ratio of the interference range to the transmission range, while the MAC protocols are characterized by contention resolution mechanisms. Based on our formulation, the impact of interference and MAC protocols on end-to-end flow performance is investigated. Our simulation results show that the end-to-end throughput is significantly degraded when R exceeds two. ACK message exchanges are also more robust to interference variation as compared to contention resolution in MAC protocols.