Adaptive cross-layer MAC design for improved energy-efficiency in multi-channel wireless sensor networks
We present a novel cross-layer design for improving energy efficiency in a wireless sensor network that utilizes a multichannel non-persistent CSMA MAC protocol with adaptive MQAM modulation at the physical layer. Cross-layer interactions are achieved through joint, traffic-dependent adaptation of the backoff probability at the MAC layer and the modulation order at the physical layer. The joint optimization of the backoff probability and the modulation order is conducted subject to a constraint oil the packet retransmission delay. Such ail optimization is shown to produce a significant improvement in the per-bit energy requirement for Successful packet delivery. Our analytical findings are verified through numerical results and computer simulations. (c) 2007 Elsevier B.V. All rights reserved.
cross-layer design csma mqam backoff probability traffic load wsn