Design And Implementation Of International Roaming And Clearing System For Single IMSI Multiple MSISDN Service

As the communications between China and other countries or regions becoming increasingly heavy, more and more people travel cross countries and regions for business using phone in both places. To meet these customers’requirements, Single IMSI Multiple MSISDN Service is released by China Mobile. Both numbers are chosen as the main-number for a telephone call automatically according to the place where the call is made. As this service using different msisdns which belong to different carriers, the international roaming and clearing operations are imported to settle the roaming data and profits.First of all, in this thesis, the business functions of Single IMSI Multiple MSISDN are stated, after the basic concepts of roaming clearing introduced, the key protocols TAP3 protocol and RAP protocal are presented importantly. Thirdly, the three-tier architecture of the system contains the data layer, business layer and access layer. Based on the priciple of high cohesion, low coupling, easily extensible, the system is decomposed into data processing, billing statistics and other subsystems, which are stated from the development and implementation point. Finally, tests are given to prove the system can support the new business well.From the actually user’s point of view, this business is convenient for our customer and to save money at the same time, so there is a great potential in the future. Seen from the perspective of the opened carrier business, it constitute a high proportion by comparsion with general roaming, and there is also a tendency towards gradually increase, which can be a sign that customer has a high perception of this business. In the development of international roaming, there should be vigorously developing new services with such high value to stimulate the telephone traffic and more international roaming gains.