行動電信網路之使用者位置追蹤及其應用

Abstract

近年來行動裝置用戶急遽增加，無線行動資料存取逐漸成為人們生活中不可或缺的一部分。現代的行動電信系統，例如:通用移動通訊系統(Universal Mobile Telecommunications System; UMTS)，提供了全球性的移動管理能力並且支援各種服務，包含語音電話、訊息傳遞、網際網路(Internet)及寬頻資料存取。另外為因應高速行車環境，車用環境無線存取系統(Wireless Access in Vehicular Environments; WAVE)可以進行低延遲的資料溝通。本研究著重在探討行動電信網路之使用者位置追蹤及其相關應用服務。 基於電信網路交換機所提供之標準統計資料，我們首先提出使用者在通訊細胞中停駐時間之數學推導公式，我們所提出之推導公式可以準確並快速地計算出正確的停駐時間，其誤差皆保持在10%以內。對於通話時間較長的情況，我們的推導公式更可達到2%以內的誤差。我們利用電信網路所取得之標準統計資料更進一步地提出了行車速度測定演算法(Speed Determination Algorithm)以計算道路之雙向平均車速，以及人口移動預測模型。人口移動預測模型可以用來預測某時間某地點之人口，經過給定時間後，其出現在其他各個地點之機率。 在車用環境無線存取系統中，我們提出了基於位置估算之移動管理機制(Location Estimation-based Mobility Management; LEMM)。相較於傳統的移動管理機制，此機制利用定位系統所提供之資訊做為輔助，有效的節省40%~90%的資料傳輸量。 最後我們提出專為行動裝置所設計之同儕運算(Peer-to-Peer; P2P)系統iP2P。iP2P利用行動電信網路之移動管理機制以及簡訊服務(Short Message Service; SMS)做為其控制協定。以簡訊之推播機制(push mechanism)建立同儕運算連線可以免去架設註冊伺服器的花費，並且有效地節省行動裝置之電源消耗。 本論文之研究成果可提供電信業者有效率之管理機制與規劃準則，以提升其行動網路之移動管理效能。

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.