Research On Opportunistic Network Routing Algorithm For Mine Safety Monitoring

The complexity of the coal mine communication environment,the wireless signal attenuation is serious,and with the dynamic advance of the mining face,wireless infrastructure cannot be deployed in time,cause a wireless coverage blind area in coal mine,unable to support the continuous transmission of mine safety monitoring data,unable to realize comprehensive,no blind area in underground safety monitoring.Opportunistic network is an intermittent-connected wireless network,which adopts the communication mode of "store-carry-forward".Data transmission does not need a complete end-to-end communication link,make use of the encounter opportunities between nodes to complete the task of data transmission.It is applicable to realize the uninterrupted transmission of safety monitoring data in underground coal mine.Due to the variety of underground data types,limited terminal node resources,miners carrying intelligent mobile terminals have certain regularity in their movement,the main research content of this paper is how to design efficient and reliable mine opportunistic network routing for the application requirements of underground safety monitoring.Miners carrying smart mobile terminals in underground coal mines can be regarded as mobile nodes,whose mobile trajectories have certain regularity.Using the moving trajectory information of nodes to assist routing decisions can improve the success rate of data transmission.In this paper,an opportunistic network routing for mine safety monitoring based on the moving trajectory information of miners is proposed.The routing algorithm is divided into multi-copy allocation phase based on utility value and single-copy transmission phase based on optimal expected energy consumption.In the multi-copy allocation phase,the algorithm calculates the node's utility value according to the historical movement trajectory,and distributes the message copy according to utility value.;in the single-copy transmission phase,the algorithm calculates the expected energy consumption of nodes to complete the data transmission according to the historical movement trajectory,and selects the node with the least expected energy consumption to complete the data transmission.There are various types of mine safety monitoring data,the importance of different types of information is different,and the forwarding priority is also different.For example,the over-limit alarm information of gas concentration has great influence on underground safety and needs to be transmitted in real time.According to the requirements,this paper proposes opportunistic network routing of mine safety monitoring based on encounter probability.The routing algorithm calculates the importance of the message according to the number of copies,the emergency degree and the remaining survival time of the message,and determines the forwarding order of the message according to the importance of the message.When a node carrying a message copy meets a neighbor node,the appropriate forwarding node is selected according to the encounter probability of the neighbor node and the destination node.The direct encounter probability and indirect encounter probability between nodes are considered when calculating the encounter probability.For the direct encounter probability calculation between nodes,the average encounter duration and average encounter interval between nodes are considered,and the most recent encounter information is given a higher weight value.This paper tests the performance of the two algorithms based on ONE simulation platform and compares them with the related routing algorithms.Simulation results show that compared with similar algorithms,the proposed opportunistic network routing algorithm for mine safety monitoring has better performance in terms of message transmission success rate,average transmission delay,control cost and average residual energy.There are 24 figures,6 tables and 65 references in this paper.