Coding-aware routing and scheduling in WiMAX-based mesh networks: a cross-layer design approach

In this paper, we propose a cross-layer design framework for the joint problem of coding-aware routing and scheduling in WiMAX-based mesh networks with unicast sessions. The model attempts to maximize the system throughput by exploiting opportunistic coding opportunities through appropriate routing and by achieving efficient spectrum reuse through appropriate link scheduling. We assume centralized scheduling at the base station and focus on minimizing the total schedule length to satisfy a certain traffic demand. Minimizing the schedule length is equivalent to maximizing the system throughput. We present a linear programming optimization model for the joint problem, which relies on the enumeration of all possible schedules. Given its complexity, we decompose the problem using a column generation approach. Our numerical results show that significant gains may be achieved when network coding is incorporated into the design. We compare the performance with that of a joint coding-oblivious model with and without transmission power control. Copyright (c) 2011 John Wiley & Sons, Ltd.