GSM-R System Wireless Networking Handover And Optimization

As a special railway communications technology,GSM-R（GSM for Railways）isnow being used in the field of the railway system and is being contributed to thedevelopment of railway industry all over the world. For the specialty of railwayenvironment, GSM-R system is required for its high reliability and also required itshigh-level requirements in cover probability and systematic redundancy.The reliability and validity of handover are important parameters for GSM-Rsystem performance. Dealing with handover problem and choose optimize method willgive positive effect to improve systematic validity and reliability. Interference plays animportant role in influencing the communication quality and the cutting off rate of thenetwork, which always impairs the communication quality and brings the networkservice performance down. The interference usually affects our network in differentnegative ways. As the core problem of network optimization，solving the problem ofreducing wireless interference becomes more important than before.In the following thesis, we introduce these problems above, and give some basicconcepts on the necessary theory. With the practical applications of GSM-R system,we’ve done some work and research in those fields.The main results are as follows:1. This thesis studies the concept about the cover probability, and introduces thecalculate method for overlap area. We also discuss the method of using wireless signalto cover redundant network and the method of calculating of path loss.2. This thesis analyzes the railway line switching abnormal cases of merging andcross sections. It discusses principles in designing cross-area railway, and proposes aproject of building distributed base stations to solve the switch problems. At the meantime, we provide the blueprint of setting up Cheng-Guan road’s wireless signal coverage,the blueprint for Dujiangyan, Juyuan, Lidui, triangular area signal cover optimizationscheme, and the Lidui branch tunnel signal cover optimization scheme for comparing.3. This thesis proposes an advance method to improve the PBGT handoverarithmetic. Comparing with traditional PBGT handover arithmetic, the advancearithmetic can access to more additional information from direction of trains,thelocation trains and the speed of trains. As a result, it can function more timely and reliable. In regard to the most widely used power budget handover arithmetic, make fulluse of forward path and train number and other known information, make Programmingto achieve the optimization arithmetic.This thesis shows the comparing results throughthe simulation experiments.4. In practical project of Cheng-Guan road railway, the author proposedsuggestions to reduce the blind area size and to avoid ping-pong effect by addingrepeater.5. The author design signaling processes can trace the interference sources throughout the duration of project optimization in practice.