| Summary: | 博士 === 國立交通大學 === 資訊科學與工程研究所 === 100 === The popularity of mobile devices grows rapidly in recent years, and the mobile data access becomes an important part of human life. Modern mobile telecom systems, such as Universal Mobile Telecommunications System (UMTS), provide a global mobility with wide range of services including telephony, paging, messaging, Internet and broadband data access. For the vehicular environment, the Wireless Access in Vehicular Environments (WAVE) system provides low latency communications. In this dissertation, we investigate the location tracking of mobile telecom users and the related applications.
Based on the standard statistics of telecom networks, we first propose a derivation of the cell residence times. The proposed approach can accurately compute the cell residence times with the error limited to 10%. For long call holding times, the errors are less than 2%. Furthermore, we propose the Speed Determination Algorithm to compute the vehicle speeds of two-way roads, and propose a model to predict how people spread from one location to another after a period of time by utilizing the standard statistics of telecom networks.
For the WAVE system, we propose a location estimation-based mobility management (LEMM) mechanism which utilizes positioning systems (e.g., GPS) to efficiently reduce 40%-90% of the location update traffic as compared with the traditional mobility management approach.
Finally, we propose iP2P, a hybrid Peer-to-Peer (P2P) system for mobile devices. iP2P reuses the mobility management mechanism and Short Message Service (SMS) as the control protocol. By utilizing SMS push mechanism to establish P2P connections, iP2P can avoid the cost for maintaining the registrar server and significantly save power consumption of the mobile devices.
The research results presented in this dissertation provide useful mechanisms and guidelines for mobile telecom operators to achieve high system performance in their networks.
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