Optimization Method of Adaptive Backoff and Duty Cycle for S-MAC Protocol in Wireless Sensor Networks

Abstract

As a matter of fact that the network traffic has a great influence on the binary exponential backoff mechanism, duty cycle mechanism, and fixed transmission power mechanism adopted by the Sensor Medium Access Control (S-MAC) protocol. The paper proposes an Adaptive Backoff and Duty Cycle for S-MAC protocol (ABDC-SMAC). In the backoff mechanism, considering the failure times of channel competitions, the length of buffer queue, and the node residual energy across the board, a cross-control backoff mechanism is proposed. In the duty cycle mechanism, the network traffic is judged by the average network flow factor. Based on the average network flow factor, the value of duty cycle can change around its initial value. In the power control mechanism, the minimum transmission power can be obtained by the Friis formula. At the same time, the exponential formula following the change of network traffic is selected and multiplied by the minimum transmission formula. The simulation results show that the performance of proposed ABDC-SMAC protocol is improved obviously on energy consumption and transmission delay.

SMAC-Based WSN Protocol-Current State of the Art, Challenges, and Future Directions

“…SMAC utilizes periodic listen and sleep, collision and overhearing avoidance, and message passing mechanisms. Several works are proposed in the area of SMAC [62,[64][65][66][67][68][100][101][102][103][104][105][106][107][108][109].…”

“…As a result, researchers use the following criteria to address the issue of fixed duty cycle and contention window for traffic adaptation in SMAC: (1) A mechanism for reversal, (2) A duty cycle mechanism; and (3) A power control mechanism for the transmission [181]. Because traffic load variations in WSN are difficult to predict, proposed SMAC backoff mechanisms dynamically adjust the contention window of SMAC to accommodate changes in network traffic load [64,68,181]. On the other hand, adaptive duty cycle mechanisms dynamically adjust the duty cycle of SMAC to account for variations in traffic load.…”

“…Challenges posed by SMAC include high energy consumption of border nodes adopting a schedule in a diverse environment [62], fixed duty cycle [63], fixed contention window [64], wasteful idle listening, and latency [65]. ere are suggested solutions to improve SMAC's limitations [66][67][68].…”