Characterizing achievable rates in multi-hop wireless mesh networks with orthogonal channels

This paper considers the problem of determining the achievable rates in multi-hop wireless mesh networks with orthogonal channels. We classify wireless networks with orthogonal channels into two types, half duplex and full duplex, and consider the problem of jointly routing the flows and scheduling transmissions to achieve a given rate vector. We develop tight necessary and sufficient conditions for the achievability of the rate vector. We develop efficient and easy to implement Fully Polynomial Time Approximation Schemes for solving the routing problem. The scheduling problem is a solved as a graph edge-coloring problem. We show that this approach guarantees that the solution obtained is within 50% of the optimal solution in the worst case (within 67% of the optimal solution in a common special case) and, in practice, is close to 90% of the optimal solution on the average. The approach that we use is quite flexible and can be extended to handle more sophisticated interference conditions, and routing with diversity requirements.