PaderMAC: A Low-Power, Low-Latency MAC Layer with Opportunistic Forwarding Support for Wireless Sensor Networks

Modern medium access control (MAC) protocols for wireless sensor networks (WSN) focus on energy-efficiency by switching a node’s radio on only when necessary. This intoduced rendezvous problem is gracefully handled by modern asynchronous approaches to WSN MAC’s, e.g. X-MAC, using strobed preambles. Nevertheless, most MAC layer ignore the possible benefits in energy consumption and end-to-end latency, supporting opportunistic routing can provide. In this paper we present PaderMAC, a strobed preamble MAC layer which supports cross-layer integration with an arbitrary opportunistic routing layer. This work specifies the PaderMAC protocol, explains its implementation using TinyOS and the MAC layer architecture (MLA), and presents the results of a testbed performance study. The study compares PaderMAC in conjunction with opportunistic routing to X-MAC in conjunction with path-based routing and shows how PaderMAC reduces the preamble length, better balances the load and further improves the end-to-end latency within the network.