A cross-layer backpressure architecture for wireless multihop networks

Abstract

Contemporary wireless multihop networks operate much below their capacity due to the poor coordination among transmitting nodes. In this paper, we present XPRESS, a cross-layer backpressure architecture designed to reach the capacity of wireless multihop networks. Instead of a collection of poorly coordinated wireless routers, XPRESS turns a mesh network into a wireless switch. Transmissions over the network are scheduled using a throughput-optimal backpressure algorithm. Realizing this theoretical concept entails several challenges, which we identify and address with a cross-layer design and implementation on top of our wireless hardware platform. In contrast to previous work, we implement and evaluate backpressure scheduling over a TDMA MAC protocol, as it was originally proposed in theory. Our experiments in an indoor testbed show that XPRESS can yield up to 128% throughput gains over 802.11. © 2013 IEEE.