Capacity Augmentation in Wireless Mesh Networks

In this paper, we address the following problem: Given a specific deployment of a wireless mesh network and given a budget to augment the capacity of N links within the network, which links should be selected for capacity augmentation in order to maximize the achievable aggregate throughput for all the flows in the network? Unlike previous research which focuses on installing additional nodes or gateways, we work on an existing deployment of the mesh network and identify optimal link positions for capacity augmentation. We model the capacity augmentation problem in single-radio single-channel mesh networks as a multicommodity maximum flow problem and derive a mixed-integer linear programming model for identifying the optimal links for capacity augmentation. For ensuring fairness among flows, we propose a concurrent flow problem formulation and derive a corresponding mixed-integer linear programming model. We propose greedy algorithms to solve the mixed-integer linear programming formulations. We also extend our analysis to the case of multi-radio multi-channel networks in which additional radios can be deployed on nodes for capacity augmentation. The simulation results of the proposed schemes for several different topologies indicate that the proposed greedy algorithms are correct and provide exact results at a fraction of the cost.