Research And Practice On Troubleshooting Methods For One Way Audio Circuit In Mobile Soft Switch Networks

Soft switch techniques are commonly used in the core network during the evolution of mobile communication from 2G to 3G. Compared with the 2G Mobile Communication System standard GSM, the R4 standard used by the WCDMA core network has a series of advantages, such as high capacity, high reliability, rich service, and so on. At the same time, the R4 standard has some shortcomings, like complex configuration, meticulous distribution. With the development of networks construction and the increase of telephone traffic and the number of users, the network coverage improves, too. However, the complaint of one way audio and cross talk is made occasionally. It's always a puzzle for telecommunication operators to solve the problem effectively.Lots of problems of one way audio and cross talk have come up in Qingdao Branch of China Unicom since the traditional exchanger was replaced by soft switch exchanger. This thesis works on the reason for one way audio and cross talk in traditional exchanger and soft switch exchanger. And a solution is proposed on the investigation of one way audio and cross talk in the aspects of academic analysis, network test, call trace, software development and effect verification.The main contents include:(1) The history of mobile communication and the development of mobile communications core network are introduced. And the theory and network structure of soft switch exchanger of the 3G mobile communications are emphasized as well.(2) The traditional solutions of one way audio and cross talk based on a deep analysis of the reason in mobile communications core network are introduced. And the comparision of the applied effects of the solutions are made.(3) Based on the practical cases, the characters of call duration are studied when one way audio and cross talk happens in soft switch networks. And the distribution of call duration with Call Data Record is analyzed. (4) A troubleshooting software system of one way audio circuit is developed. Based on the call duration characters and the user calling model, the condition and the basis of troubleshooting against soft switch exchanger are study. And the feasibility and the effect of the software are verified through the analysis of some typical troubleshooting cases.