The Study Of Multiple Unit Train Coverage Optimization Of Beijing-guangzhou Railway Anyang Section

With the large-scale speed-up and diagram adjustment of Chinese railways, multiple unit trains have been running on CRH railway main line. The average speed on the Beijing Guangdong Railway is 145km/h, and the maximum speed reaches 250km/h. Due to the Doppler effect during the high speed movement and the attenuation of the building material of the multiple unit train, problems such as weak reception field, repeated cell selection, low quality of connection, high dropped call rate and switch failure rate raise. The issue of cell phone coverage on multiple unit trains strongly affects the experience of users, so the there are demand for work to optimize the coverage on multiple unit train. The article is made based on Beijing Guangdong Railway Anyang section. The problems in wireless signal coverage on high speed trains, such as penetration loss model, theory calculation of the scheme, the project engineering, and actual coverage performance are summarized, and the merits and drawbacks are pointed out for each solution to the coverage issue. A railway special network was selected to optimize. According to the actual situation of Anyang section, the solution of setting up railway special network using micro cellular network equipment was adopted, and the coverage level was improved considerably. But with the trial run of railway special network and introduction of new CRH5, the railway special network set up by micro cellular network shows inadequate penetration capability, disruption fault of the main equipment micro cellular network occurs frequently due to the adverse environment; and the number of source area becomes too large and the switching relation and parameter set is too complex, due to limited coverage distance of the micro cellular network. In order to solve the above issues and improve the coverage level and reliability, reconstruction plan was done based on the original railway special network, railway coverage was completed using "source cell+ GRRU optical fiber remote equipment", antenna spacing was adjusted, remote terminal equipment was added, the number of source area was reduced by "one for more" fashion. The railway coverage and reliability of the special network of Anyang section was further improved through the reconstruction.