Key Technologies On Location Based Services Platform And Location Management

Combing the author's theory research and practice, this thesis addresses main work done by the author on the research. The main work done by the author is separated into two parts: the first part presents the system architecture of Gateway Mobile Location Center based on 3GPP (3rd Generation Partnership Project) standard, AGPS (Assisting Global Positioning System) mobile positioning platform based on secure user plane, CELLID (Cell Identifier) based mobile positioning platform for China Mobile, integrated mobile positioning platform for China Unicom. And then it presents the performance model for Gateway Mobile Location Center in 3GPP based on queue theory and proposes new load balancing algorithm and differentiated services algorithm for mobile positioning platform; the second part first presents new location management scheme and call setup mechanism based on three-tier database in 3G, then establishes the total cost function based on theory analytical method. Experiments have been taken to verify the correctness of the research and the outcomes show that new mechanisms have better performance.The principal contributions of the work presented in this thesis are:(1) Based on the system architecture and software structure and message flow of GMLC (Gateway Mobile Location Center) in 3G, this thesis presents the performance model based on queue theory. We analyze the system average response time and obtain closed form expressions for performance metrics of average response time. The model parameters are estimated through experiment on real system. And we validated this performance model through simulating and measurement. The results of experiments show that the model has the ability to describe the real performance situation of the system, and it is valid for GMLC.(2) Load-balancing algorithm is one of the key algorithms for mobile location platform. Based on the system architecture and software structure of mobile location platform, a new dynamic load-balancing algorithm is proposed. It bases on dynamic feedback and imports the increment for admitting new request into the load forecast. It dynamically adjusts the dispatching probability according to the remainder process capability of each node. Experiments on the performance of algorithm have been taken in laboratory and the algorithm is compared with Pick-KX algorithm and DFB (Dynamic FeedBack) algorithm...