Efficient Throughput and Loop-Free Routing: An Adaptive Second-Order Backpressure Algorithm

The backpressure routing method offers a dynamic resource allocation approach that achieves optimal throughput. However, the method's sole dependence on the first-order backlog difference between nodes leads to poor convergence and may result in unnecessarily long paths, potentially causing loops when unrestricted. In this work, we address both transmission cost and computational complexity concerns. We introduce a second-order backpressure algorithm (SBP) featuring adaptive shortest routing, a second-order backlog metric, and a two-level queue mapping structure. We validate this novel backlog metric through Lyapunov optimization techniques. Simulation results demonstrate that while ensuring throughput, our approach effectively reduces end-to-end delay and eliminates routing loops without imposing specific constraints.