LAUSR

It is well known that backpressure routing and scheduling can achieve optimal operation in multihop networks. However, the joint routing and scheduling nature of backpressure imposes challenges for practical implementation since many off-the-shelf network nodes cannot be easily changed to match the synchronous scheduling and routing functionality of backpressure. Toward this end, we propose a two-tier data queue structure to separate routing from scheduling and design a novel modular and asynchronous backpressure (MAB) based on the Lyapunov optimization technique. In MAB, source rate control, routing selection, and session scheduling can be asynchronously and independently implemented, which performs at the transport/network/link layer, respectively. Thus, MAB is readily deployed with current infrastructure, and all network nodes can easily employ MAB partially or fully. Simulation results show that MAB maintains optimal performance of the classic backpressure.