Flush: A Reliable Bulk Transport Protocol for Multihop Wireless Network

We present Flush, a reliable, single-flow transport protocol for sensornets, and show that it can efficiently transfer bulk data across a 48-hop wireless network. Flush provides end-to-end reliability, minimizes transfer time, is energyand memory-efficient, and adapts robustly to changing network conditions. The protocol requires no special control packets to adjust its rate. Flush nodes propagate rate information against the direction of data flow by snooping on next hop traffic. We show that Flush closely tracks or exceeds the maximum achievable fixed rate over a wide range of path lengths. Flush is useful for many sensor network applications whose main requirement is to transmit all collected data to the edge, which include environmental monitoring, structural health monitoring, and protocol testing. Indeed, we collected the Flush performance data using Flush itself.