Reliability Research Of Wireless Network In Urban Rail Transit Vehicle

In the city life, the metro has become the preferred way to travel. To the safe operation ofsubway involves many aspects, including security, personnel security, natural disasters emergencyequipment and so forth. In the subway safety equipment, the normal operation of the doors isparticularly important. If the small problems of the door can be found before fault actuallyhappened, nip in the bud, is more active choice. Therefore, to obtain the running status informationof the door and realize remote monitoring of the door is the main research content of this topic.This topic is based on information acquisition front-end device on the basis of existing door.Using the "chain+clustering" topology to the front-end device with a wireless transceiver moduleof an Ad hoc network. The nodes inside the same carriage transfer data to the aggregation nodethrough the cluster communication, the aggregation nodes of different carriages transfer data to thegateway node through the inter-cluster communication, and then connect to the mobile Internet toupload the data to the remote server. Technicians can analyze the cause of the malfunction by theinformation uploaded by the door control system and command field staff to solve the problem andensure reliable operation of the train.This paper studied the traditional indoor propagation loss model, such as free space model, theattenuation factor model, as well as Keenan Motley model, etc. For special environment inside thesubway cars, this paper proposed loss model subway cars suitable for signal transmission. Based onthis model, we studied the initial channel access mechanism. To solve the hidden terminal andexposed terminal problems, this paper proposes a TDMA scheduling algorithm suitable for subwaycars nodes, according to the time slot distribution channel resources, to ensure that each node datareal-time and reliable transmission. Finally, we studied the wireless network topology structure,planar topology structure and hierarchical structure, and subway car node model. Based on this, thispaper puts forward several different wireless network scheme, analyzes the transmission reliability,the advantages and disadvantages of different network schemes, and use the OMNET++simulationsoftware to compare the reliability of the network scheme, verify that by reasonable networkscheme design to improve the door of the reliability of the information collected is feasible andmeaningful.