Application Study On Key Technologies Of Radio Resource Management Of GSM-R Network In Marshaling Yard

GSM-R has been in a fast development period in China and it will play a more and more important role in the construction and operation of China railway. There is only four mega-hertz spectrum in GSM-R with many applications,for example,the railway emergent call,the train schedule,the train control,passenger information service and so on.Different application demands different quality of service.These different services demand different resources.Therefore,GSM-R system is a severe resource restricted system.Marshaling yard plays an important role in railway transportation organization.The traffic in marshaling yard is large and the topography environment complex.If radio resources in marshaling yard can be used efficiently,it will play a promoting role in the construction of GSM-R network.The voice and data simultaneous transmission mode has been researched. According to application demands in marshaling yard,the VGCS signaling flow has been modified and complemented in order to realize voice and data simultaneous transmission function in all kinds of VGCS situations which has promoted the development in this kind of GSM-R technology area.Through research on packet data service resource mode and the basic network structure,protocol hierarchy mode,GSMS entity,the transmission procedure and signaling flow of short message transmission during an ongoing voice group call in the circuit switched domain has been improved in order to propose the transmission procedure and signaling flow of the short message transmission during an ongoing voice group call in GPRS network.The air resource is occupied less when the short message is transmitted in GPRS network compared to the circuit switched domain. Therefore,the former is more proper for the railway mobile communication system whose spectrum is restricted.According to the actual service demands of the XinFengZhen marshaling yard,the multiple reuse pattern technology which can reduce the frequency reuse degree and improve system capacity has been used to plan the frequency.Do the interference performance analysis of the designed multiple reuse pattern frequency plan scheme. The simulation results show that the designed scheme can satisfy the C/I demands of the first order adjacent frequency and second order adjacent frequency of Standards of Ministry of Railways. Water filling power allocation algorithm is combined with the dynamic channel allocation algorithm.Fairness among users has been considered in this new algorithm compared with the existing dynamic channel allocation algorithms based on the base station.The simulation of the system performance according to different channel gain factor and different power allocation algorithms has been done.Simulation results show that system throughput and user dissatisfied probability which are the two indexes measuring system performance are related to frequency reuse degree namely channel gain,the number of users in system and the adopted power allocation algorithms.When the algorithm is used in actual network,the actual network traffic demand and frequency plan scheme should be considered when the value of the channel gain factor and power allocation algorithm have been determined in order to obtain better system performance.Key technologies of radio resource management have been used in marshing yard in order to improve using efficiency of radio resource and increase system capacity which possesses guiding significance for construction of marshaling yard in GSM-R network in the future.