Low Power Wireless Protocol for IoT Appliances Using CSMA/CA Mechanism

Abstract

Authors propose solution in communication for low power embedded appliances, for system consists of many low power transmitters and one receiver. Transmitter is supplied from battery and works in loop: run program, send data, go sleep. Communication is based on ISM band on frequency 868 MHz. Estimated worktime of transmitter on one battery is 12 years, with average current in sleep about 2 uA. Communication between transmitter and receiver is one-sided. The transmitter does not receive any acknowledgement if the receiver has received data packet, due to reduce energy consumption by transmitter. In case to avoid lost packets, authors applied CSMA/CA (Carrier-sense multiple access with collision avoidance) mechanism. CSMA/CA mechanism is designed to check if channel is free before sending data. Data are sent, only if channel is sensed to be free.