Anycast Backpressure Routing: Scalable Mobile Backhaul for Dense Small Cell Deployments

Dense small cell (SC) deployments pose new architectural and transport level requirements. It is expected that they will require local multi-hop wireless backhauls in which some SCs with high capacity links towards the core act as aggregation gateways. To enable scalable deployments, there is the need of routing schemes able to handle dynamicity coming not only from increasing traffic demands and varying wireless link quality, but also from incremental gateway deployment. This letter proposes Anycast Backpressure (AB), a practical distributed anycast routing protocol designed to scale with the number of gateways and to exploit path and gateway diversity. The distinguishing feature of AB is that under increasing traffic demands, it opportunistically exploits uncongested gateways. To distribute traffic among the gateways, AB solely relies on 1-hop neighborhood queue backlog and geographic information. Ns-3 simulations show that, compared to state-of-the-art single-path and multi-path multi-gateway schemes, AB results in up to 40% gains in aggregated throughput and 99% reduction in latency for the evaluated scenarios.