GSM-R Network Planning And Key Issues Analysis In Co-line Regions Of Railway

As a standard of dispatching communication for railway, GSM-R was introduced into China from Europe in 2000 and has been widely used in a number of railway lines and large marshalling yards.At the very beginning, GSM-R network of new railway is only planned for a single line or marshalling yard, the planning environment of which is very simplex.With the rapid construction of High-Speed railways and electrification of existing lines and marshalling yards, the environment of the wireless network needs to handle is becoming more and more complex. Especially in the place where the railway line completely parallel or cross another railway line or marshalling yard, wireless coverage, frequency planning and operational implementation are the serious problems need to face in wireless network planning. After co-line problems turning up, it becomes an urgent research topic of how to make full use of the frequency resources, and make a reasonable planning for wireless network in the co-line region mentioned above, and finally make a balance of the capacity, coverage, quality and cost under the precondition of satisfying engineering design specifications.For the reasons above, GSM-R network planning and critical issues in the co-line region are deeply researched. Based on the current construction situation of China railway, GSM-R bands division, business model, railway traffic model, wireless propagation model, co-channel and adjacent channel interference model, network coverage model and engineering design specifications are elaborated. This paper also defines five types of co-line region and analyzes the business requirements of high-speed co-line region and marshalling yard. New technology is also brought out. GRRU technology is introduced as several network planning schemes for different co-line types and compared to the schemes from frequency planning, interference status, switching and reliability, then a optimal program is concluded, which ensures the safety and reliablity of railway communication and saves investment.To verify the feasibility, take the parallel co-line region of Zhengzhou-Xi'an high-speed railway and Xinfengzhen marshalling yard as an example. Based on Okumura-Hata model the C/I formula is deduced which can meet the construction indicators, and also a simulation analysis of frequency reuse distance is given. The results show that,the solution of railway line region wireless network planning proposed, to some extent to ease the regional railway and the line frequency resource shortage problem and improve the quality of wireless coverage in co-line region, and to meet specific business requirements of the railway.