Hybrid mine wide communication system for surveillance and safety of the miners in underground coal mines

In this paper, a hybrid, mine wide communication system for online monitoring of miners during working hours is described. The developed system consists of surface computer with monitoring software, base stations and miner kits. RS485 is used as a wired link between surface computer & base stations whereas low frequency RF link is employed between miner's kit and base station. Based on the underground mine wireless propagation modeling and some communication facts, Sub 1GHz has been selected as operating frequency of the system. Software for the monitoring of the miners at surface computer has been developed. This software keeps track of the miners with the help of the received information from base stations and issues warning signals to the miners in any emergency condition.