Multichannel preamble sampling MAC protocol for wireless sensor networks

In this article, a multichannel preamble sampling MAC protocol, MCPS, especially tailored for wireless sensor networks, is proposed and thoroughly evaluated. MCPS is a low-power MAC protocol operating on multichannel using carrier sensing for collision avoidance. Specifically, MCPS exploits all the non-overlapping channels provided by IEEE 802.15.4 physical layer. Basically, MCPS uses one dedicated common control channel to wake up an intended receiver using a preamble sampling technique. However, data transmission takes place in a dedicated data channel. Indeed, MCPS allocates to every pair of sensor nodes a unique data channel that aims at being 2-hop conflict free. Hence, the probability of collision is highly reduced and even completely mitigated in some scenarios. Moreover, MCPS allows each sensor node to dynamically adjust its transmission power when sending strobed preamble or periodically generated data. Indeed, for each possible distance separating a pair of communicating nodes, MCPS adapts the appropriate transmission power and selects the appropriate data channel. Using multiple channels, MCPS allows multiple simultaneous data communications along with handshaking on the common control channel, hence reducing the end-to-end delay and improving the throughput while being energy efficient. MCPS has been implemented using OMNET++ simulator under INET framework, on top of the IEEE 802.15.4 physical layer, which was improved to support the multichannel communication. The authors compare the performance of MCPS with McMAC and X-MAC. Simulation results show that MCPS greatly improves the network performance especially in terms of throughput, waiting time, end-to-end delay, and energy per bit.