Research On Railway Gprs Service Model And Resource Scheduling

With the massive construction and information development of railway system in China, the amount of railway services on Global System of Mobile communication for Railways and General Packet Radio Service (GSM-R/GPRS) keeps growing. In recent years, there is a demand to bear more communication services on GSM-R/GPRS to promote the informatization of railway system in China. GPRS uses a packet switch technology which has some benefits such as sharing resource, high efficient data and signaling transmission, and it can take full advantage of network as well as radio resources. Due to the situation that the radio resources are really scarce, it is a proper choice to put more railway data services on GPRS before the application of next generation wireless communication system for railway. However, some railway data services should meet high safety, reliability and delay requirements, developing railway GPRS services blindly may lead to resource congestion and the drop of Quality of Service (QoS) on the condition that the radio resources are limited, which also brings security problems to the railway transportation. As a result, the railway department needs to establish the service model and resource scheduling strategy suitable for railway GPRS, which guides the railway GPRS service development designedly, and to lay the foundation for the railway new cell resource planning.Although there are some research conclusions for GPRS in public network, the railway GPRS have a lot of differences with the GPRS public network such as application environment, service features and requirements., it will not meet the railway application requirements if we just copy the configuration of GPRS in public networks. Therefore, the first issue to be considered is to research service model and resource scheduling strategy suitable for the application in the railway GPRS. This paper first analyzes three typical railway scenes based on the characteristics of railway spatial distribution including the railway GPRS service feature model of the railway line interval, station area and train maintenance field, and puts forward the railway GPRS transmission protocol three-layer model according to the railway application, that is service process model and service transmission process model to describing railway GPRS service model; Then, this paper researches typical service arrival process model of the railway line interval, station area and train maintenance field three railway wireless communication scenes, and researches the air interface transmission process model according to the working mechanism of railway GPRS and characteristics of railway GPRS service. Last but not least, a resource scheduling strategy for railway GPRS based on aforementioned service model is proposed, to lay the foundation for railway GPRS reliable bearing railway data service.This paper builds railway wireless communication scene simulation test plat based on the railway actual scenes, and makes a farther research of GPRS service model based on the plat, to solve the actual problem appear in China railway GPRS application. Moreover this paper also tested the performance of GPRS data transmission of different coding methods based on this plat, put forward the application strategies of different channel coding methods in the railway, and enrich the methods of railway GPRS bearing data service.