Applications Of Location Based Service For Mobile Equipments Based On 3G Network

As the technology of mobile communication based on 3G network and the functions of mobile communication terminal equipments developing fast, it makes a great progress of intellectualized. With the standard of living growing everyday, mobile phone not only used to provide the voice and short message operations anytime and anywhere, some mobile increment operations meet marking needs like mobile-phone stock-jobbing and WAP have shown their great developing potential. Location Based Service, LBS is a new operation of getting the information of end-user's position (coordinate of longitude and latitude) from communication networking. With the supporting of electronic map platform, it provided client a new operation of LBS what they need.This paper points out the important meaning of LBS in modern life based on the background of problem studied, and analyzes the current status and developing trend of the applications of LBS based on 3G network. And the basic principles, features and problems of moving location technique based on 3G network platform and LBS involved are summarized. We made some improvements for the inadequate of TDOA algorithm based on 3G network. In this paper, J2ME, XML, Mobile SVG technologies are used to realize a new framework of Mobile GIS.Firstly, this paper researched new location technologies based on 3G wireless networking: CELL/CELL-ID, OTDOA-IPDL, A-GPS; and their process. Then, it improved the TDOA location algorithm, designed CT and LE-WLS algorithm. CT algorithm has the advantage of highly positioning accuracy, the results can be given definitely, and less computation; the advantage of LE-WLS algorithm is that with less searching steps it can get a high level of positioning accuracy in the condition of small search area. According to add-transmit delay obey the characteristics of uniform distribution, it estimated the mean and square error of add-transmit delay and amended the measured value of TDOA in NLOS transmission environment. Design the algorithm of amending non-line of sight error based on TDOA. In the end, according to the criterion of 3GPP, the designing of overall framework programme, interface and functions are provided in this paper. According to the framework function of 3G-WLCS system, it designed the system framework for JAVA supported mobile-phone positioning terminal, simulated and achieved the client of corresponding logic functions.