Optimal Resource Allocation for Wireless Mesh Networks

6.1 Introduction Wireless networks enable ubiquitous information and computational resource access , and become a popular networking solution. Recently, wireless mesh networks (WMN) [1, 2, 3, 4, 5, 6, 7] have attracted increasing attention and deployment as a high-performance and low-cost solution to last-mile broadband Internet access. In this chapter, we study the problem of resource allocation in wireless mesh networks. Our goal is to design effective resource allocation algorithms for wireless mesh networks, which are optimal with respect to resource utilization and fair across different network access points. Compared with traditional wireline networks, the unique characteristics of wireless mesh networks pose great challenges to such algorithms. Particularly, the wireless interference issue of mesh networks needs fresh treatment: flows not only contend at the same wireless mesh router (contention in the time domain), but also compete for the shared channel if they are within the interference ranges of each other (contention in the spatial domain). This challenge calls for a new resource allocation framework that could characterize the unique features of wireless mesh networks. To address this challenge, we present a price-based resource allocation framework for wireless mesh networks to achieve optimal resource utilization and fairness among competing aggregated flows. In this chapter, we first model the resource allocation problem as an optimization problem: given network resources with constrained capacities and a set of users (e.g., aggregated flows from access points of mesh networks), one tries to allocate resources to each user in a way that the overall satisfaction (so called utility) of all users are maximized. We show that such an optimization goal could naturally lead to different fairness objectives when appropriate utility functions are specified. We further present a price-based distributed algorithm which solves this optimization problem and thus provides fair and optimal resource allocation. We instantiate the above generalized resource allocation framework to the wireless mesh networks. The key challenge comes from the shared-medium multi-hop nature of such networks, namely location-dependent contention and spatial reuse.