IEEE 802.11b-based access scheme with coordinated sleeping for wireless sensor networks

This paper proposes a reliable access scheme in the Medium Access Control (MAC) layer of Wireless Sensor Networks (WSN) called Explicit Reservation with Coordinated Sleeping (ERCS). Nowadays, most access mechanisms proposed for WSN are costly and difficult to build an entire network. However, the research of ERCS is significant since it is the one based on the widely used IEEE 802.11b which is already a mature technology in wireless communications. Thus ERCS can facilitate implementations in the practical applications, which is a brand new resolution for WSN. The strategies of ERCS mainly include explicit reservation and coordinated sleeping. First, the Explicit Reservation executed by the sink node can guarantee the fast and reliable accessing of the reserved sensor nodes. Second, through Coordinated Sleeping, sensor nodes which do not occupy the wireless channel or do not have data to send can go to the sleeping mode to save energy after the coordination with the sink node. In the end, based on the analysis of the novel Markov chain model and OPNET simulations with various network scales under large open NLOS condition, it is substantiated that the ERCS can obtain favorable performances in terms of low energy consumption, good scalability and high throughput.