Congestion-Aware Spatial Routing in Hybrid High-Mobility Wireless Multihop Networks

We develop a spatial framework to provide end-to-end delay estimates and guarantees in mobile multihop networks. The novel aspect of this approach is the attribution of network and MAC layer congestion to space, which enables congestion-aware routing and provides delay guarantees over a much longer duration than that achieved by the routing algorithms based on individual nodes. In a mathematically rigorous setting, first, we prove that over the duration during which the node density and the traffic pattern remain stationary, the expected values of local congestion and end-to-end delay roughly remain invariant. Second, we present an accurate method of delay estimation over geographic paths, namely path integration, and derive an upper bound for its estimation error. Further, we develop a congestion-aware routing protocol that utilizes the spatial maps of network congestion to enable delay-optimized routing of real-time applications. Through extensive QualNet simulations, we perform a detailed evaluation of the presented framework and the routing protocol in a realistic setup. The simulation studies demonstrate that the proposed scheme provides substantial improvements in the delivery of real-time applications for a wide range of node densities, velocities, and data traffic.