Multipath routing for mmWave WMN backhaul

Static Wireless Mesh Networks (WMN) based on high capacity pencil-beam millimeter wave (mmWave) links offer an attractive solution for small cell backhauling in 5G networks. However, the delay targets in 5G are such that it is quite challenging to develop adequate link scheduling and routing mechanisms. Furthermore, the susceptibility of mmWave radio links to adverse weather conditions and other obstructions in the line-of-sight line makes it necessary that routing is able to cope with frequent link degradations and failures. We propose an approach that divides the problem into two parts - finding first a suitable set of so called primary paths and then optimizing the link schedules for those paths. In this paper, we present a routing algorithm that produces the required primary paths and several backup paths for all source-destination pairs. Furthermore, we describe a hierarchical fault recovery system that includes various protection and restoration methods that are acting in different time scales to ensure fast reaction to failures and then optimal adaptation to the changed situation.