Research On Key Technologies Of LTE-R Intelligent Services

The evolution of GSM for Railway to LTE-R(Long Term Evolution for Railway)has become a trend of the times and a necessary requirement of technological development and industrial upgrading.Currently,China Railway Corporation and UIC(International Union of Rail ways)are actively advancing the LTE-R standard process.IN(intelligent network)service is one of the key service on the railway and the test project for the 2018 Beijing-Shenyang LTE-R test line.However,the current standards authority such as 3GPP(The 3rd Generation Partnership Project)do not have any agreement on how to realize the IN service of railway based on LTE(Long Term Evolution).The paper can provide significant reference for the research on LTF-R intelligent network architecture and service.Based on the LTE-R cluster system and combined with the 3GPP standard and the public network implementation,this paper compares three existing 3 kinds of schemes of the Interaction between IN and SIP core(Session Initiation Protocol core)network and chooses the solution of upgrade to determine the LTE-R intelligent network architecture.Based on the LTE-R intelligent network architecture,two IN service scheme,iFC triggering and MCPTT triggering,are proposed according to the triggering mechanism and location of the IN service.And then this paper,for iFC triggering scheme,deeply does some research on LTE-R FN registration,FN addressing and location-based call barring services from the aspects of service description,iFC(Initial Filter Criteria),SIP request message design,signaling flow and service logic.Because on the current network,location-based call barring service can only solve the fixed scenario,a new location-based call restriction solution is proposed to solve the call barring problem in the mobile scenario.In this solution,The location information of the called party and the limit area are the two key service information.This paper put forward API query and dispatch area dynamic matching solution to acquire them.Finally,this paper conduct a function verification test.Simulation model is built up for the test of the FN registration and FN addressing service of iFC triggering scheme.In addition,the MCPTT triggering scheme is tested on the physical network.The test items are FN registration and FN addressing services.It can be seen from the test results that both schemes can realize the IN service in the LTE-R MCPTT cluster system.In the end.the two schemes are analyzed and compared from different aspects,which can provide some reference for the future research and implementation of LTE-R IN network architecture and IN service.