Joint Routing, Scheduling and Variable-Width Channel Allocation for Multi-Hop WMNs

Recent research results have shown that channel width is an important control knob that can be easily adapted through software and can be used for achieving higher system throughput and better energy efficiency. In this paper we address the problem of joint routing and transmission scheduling in a multichannel wireless mesh network with variable-width channel allocation. While narrower bands split the total available spectrum into more non-overlapping channels allowing more parallel concurrent transmissions, wider bands increase the capacity of the communication links. We present a cross-layer problem formulation which incorporates multi-path routing and link layer scheduling. We model this combinatorial complex problem as a mixed integer linear program and present a primal-dual decomposition method for solving it. Our method has always shown to strike a good balance between often conflicting objectives to achieve higher system performance. Numerical results revealed that up to 57% improvement in network performance is obtained when variable-width channel assignment is used against the best fixed-width channel assignment for larger networks; this is due to the capability of the former in achieving a good balance between higher concurrency and better control of interference.