整合 GPRS 與 Wireless LAN 資料網路之兩階層式架構與通訊協定

Abstract

近幾年來，行動電話系統的建設日益完善。隨著網際網路的興起，行動電話的使用者除了原有的語音服務之外，更希望能取得數位資料的服務，例如：收發E-mail、瀏覽網頁或是線上購物。為了達到這些功能，GPRS定義了傳輸數位資料所需的通訊協定和網路元件，使得支援GPRS的手機能夠取得數位資料的服務。在此同時，無線區域網路設備的研發與行動式網際網路通訊協定的制訂，使得無線區域網路的架設得以實現。而在原有的個人通訊系統中，就有多階層式的觀念，藉由整合數種不同的個人通訊系統，使得使用者能夠享受到個別系統中的優點。在本論文中我們提出了整合GPRS與無線區域網路之兩階層式系統架構的數個方法，讓支援兩階層式系統的行動主機能夠在不同的系統之間自動切換，以增加整個系統的涵蓋面積以及傳輸資料的效率。最後我們會提出一些簡單的模型，來評估兩階層式系統的效能。

In recent years, the mobile telecommunication system has become more mature day by day. Accompanied with the development of the Internet, besides the earlier voice service, cellular phone users are desirous of accessing to the digital data services, such as sending and receiving E-mails, browsing homepages, or doing shopping through the Internet. To achieve these goals, GPRS defines the protocols and the network components needed for the digital data transmission. GPRS makes it easier for those cellular phones that support GPRS to access digital data. In the meantime, the Wireless LAN is becoming more and more popular because of the development of the Wireless LAN equipments and the establishment of the Mobile IP. Moreover, there has been a multi-tier concept in the original Personal Communication System; that is, by integrating different kinds of Personal Communication Systems, users can benefit form the advantages of the individual systems. In this thesis, we propose several schemes to integrate GPRS with Wireless LAN into a two-tier architecture. With the Wireless LAN/GPRS two-tier architecture, a two-tier mobile node can spontaneously switch between GPRS and Wireless LAN network. Therefore, the mobile node can have a wider roaming area or a higher data transmission speed. Performance results show that our design is every effective.