On The Design of Resilient and Reliable Wireless Backhaul Networks

The exponential growth of traffic in mobile networks is leading to increased pressure on the infrastructure of mobile networks and in particular on their backhaul networks. It is more critical than ever to carefully plan backhaul networks. In this paper, we formulate and solve the problem of hierarchical wireless backhaul network design. In formulating our problem, we cover different requirements, namely: topology simplicity, network resiliency, and link reliability. We formulate the problem as an Integer Linear Programming (ILP) problem, allowing us to solve the problem to optimality. Furthermore, we provide a graph theory-based algorithm that allows solving the problem over a large scale. The proposed algorithm exploits the properties of the graph that represents the network. The results of our evaluations in various network scenarios demonstrate the efficiency of our ILP formulation and the proposed algorithm in keeping the backhaul network simple, resilient, and reliable. Using a practical channel propagation model and different node densities that are representative of small-scale and large-scale urban environments, our results also show that even with high resiliency requirements, the network traffic can be backhauled with only 5-10% of the nodes for the considered densities. Our results also demonstrate that our algorithm leads to near-optimal solutions in different scenarios.