The existence of multiple gateways, as is a common case in Wireless Mesh Networks (WMNs), brings the possibility to improve network performance. However, previous studies, including both heuristic-based works and theory-driven crosslayer design works, cannot guarantee an optimal exploitation of multiple gateways. In this paper, we focus on exploiting multiple gateways optimally to achieve maximum network utility. We first extend the current framework of cross-layer design and formulate network utility maximization problem under WMNs with multiple gateways as a constrained optimization problem.
Then by solving this optimization problem, we propose a novel joint traffic splitting, rate control, routing and scheduling algorithm called CLC DGS, which splits and distributes network traffic into multiple gateways in an optimal way. We prove that CLC DGS can achieve maximum network utility. Finally, we run extensive simulations to demonstrate that compared with the previous methods, CLC DGS significantly improves the performance of WMNs under various network environments including gateway heterogeneity, link heterogeneity and different interference models.