Research On Wireless Sensor Network MAC Protocol Based On Self Power Supply

Wireless sensor network (WSN) is a self-organized network consisting of sensor nodeswith low cost, low power consumption, and sensor nodes can communicate with each otherwireless. Sensor nodes usually are supplied by batteries. But the electricity of the batteries islimited, the batteries replacement is difficult. With the development of low power electronictechnology and energy collection technology, collecting energy from the surroundingenvironment becomes a method to solve the energy problem.The existing MAC protocols mainly consider reducing data collision and energyconsumption to maximize the life cycles. This paper introduces the characteristics of MAC layerand the main energy consumption of wireless sensor network, and introduces the classifications ofMAC layer protocols. Then we analyze some typical MAC layer protocols and introduces theiradvantages and disadvantages.According to the characteristics of self powered wireless sensor network with infiniteenergy and temporary shortage of energy, this paper proposes the EDFSA protocol based onFrame slotted ALOHA protocol. EDFSA protocol is a competitive MAC protocol. Theenergy of energy storage device is managed quantitatively. The center node predicts theamounts of data transmission by numbers of successful slots and failed slots, then selects theappropriate frame length. Self powered nodes transfer data in a randomly selected time slot.This protocol is applied to a single-hop network with a large number of nodes sending data tothe center node. And it reduces idle listening time compared to the traditional competitiveprotocols(such as CSMA/CA). It also improves the channel utilization and throughputs, andenhances the timeliness. This protocol manages the energy and improves the energyutilization. It also avoids node crashes caused by temporary energy shortage.In this paper the transmission efficiency and channel utilization of EDFSA protocol arederived. The results prove its great transmission efficiency and channel utilization. And wecan adjust the transmission efficiency and channel utilization to meet the practicalrequirement. Then we prove the good performances of EDFSA protocol by simulation.Finally, a simple hardware design is made to prove its feasibility.