Research On Spectrum Demand Forecasting For Railway Radiocommunication System Between Train And Trackside

In the past 10 years,high-speed railway and related industries in China have been developing rapidly.The 450MHz communication system and 900MHz GSM-Railway communication system for China Railway Radiocommunication System between Train and Trackside are hard to bear railway communication service by now,and LTE-R system will gradually replace the existing system as the next generation railway communication system.At present,except for 1.5MHz bandwidth in 450MHz band dedicated for railway network,the frequency band suitable for high speed railway below 1 GHz is scarce,the rest of the band are occupied by telecom operators or related radio industries.In order to promote the spectrum application work for China's next-generation RSTT and speed up the construction of LTE-R system,it is necessary to study RSTT spectrum requirements in the future.The main work of this paper is as follows.First,the current status,main technologies and applied frequency band of RSTT are introduced.Second,the commonly used prediction methods for spectrum demand are studied,including:ITU-R M.1390 method,ITU-R M.1768 method,spectrum demand prediction method based on hot spots and prediction method of spectrum demand for satellite mobile service communication system.Third,based on different delay constraints of different service categories,a LTE-R spectrum requirement prediction method is proposed and used to estimate spectrum needs of LTE-R in the future,which is about 16MHz.The impact of engineering spectrum efficiency and video service on LTE-R spectrum demand is also analyzed.Fourth,based on trend extrapolation,a RSTT spectrum requirement prediction method is proposed and the future spectrum demand of RSTT is predicted by this method.Meanwhile,the influence of the number of base stations and the traffic diversion ratio on prediction results is analyzed.This paper comprehensively analyzes and studies the spectrum demand forecasting method of Railway Radiocommunication System between Train and Trackside.The conclusion can provide useful information for the planning of spectrum resources in China's railway communication system in future.