Bit-Map-Assisted Energy-Efficient MAC protocol for Wireless Sensor Networks

Abstract

© 2018 SERSC Australia. Time Division Multiple Access (TDMA) based Medium Access Control (MAC) protocols allocate one or more time slots to each sensor node. A node transmits its data during these slot(s) and keeps its radio OFF during all other slots. This inherently reduces idle listening, overhearing, and collision which are the major energy consuming factors. Some MAC protocols include a control period within each time frame. A node that has data for its Cluster Head (CH), books one or more slots by sending a data request (inside a control packet) during the control period. In response to the requests received, the CH sets up and broadcasts a schedule for the source nodes. Each source node transmits in its own slot(s) and keeps its radio OFF during the rest of the data transmission period. In the proposed MAC protocol named Bit-Map-Assisted Energy-Efficient MAC (BEE-MAC), the schedule is broadcasted only once in a round, and is followed throughout the duration of the round. This saves the energy which would have been consumed otherwise, in sending and receiving schedules, multiple times in a single round. The energy consumption in BEE-MAC is compared with the energy consumption in an existing MAC protocol. The results, which have been derived through mathematical calculations, show that BEE-MAC can save a considerable amount of energy by allowing the CH to broadcast the schedule only once in a round.