行動無縫式TCP連線環境架構之研究

Abstract

隨著通訊產業的發達，目前已經發展出很多套無線通訊的技術，由於這些技術遵循的規格皆不同，造成互有利弊的情況，如：WLAN的傳輸率較高，但是訊號覆蓋範圍較小；GPRS的訊號覆蓋範圍較廣，但是傳輸率較低，而且傳輸資料需要額外的費用。

本論文藉著結合WLAN和GPRS的優點提供給使用者一個更具效益的TCP連線環境。當使用者建立TCP連線時，此連線環境會根據使用者目前所處的環境條件，去動態選擇無線通訊的技術使得資料的傳輸能夠達到最高的傳輸率和最低的費用，並且盡量降低在轉換技術時出現的延遲時間。

With the rapid development of communication industry, there are many technologies developed to do wireless transmission. Because they all follow different standards, they have their own advantages and disadvantages. E.g. WLAN has higher transmission rate but shorter transmission distance, GPRS has longer transmission distance but lower transmission rate, in addition, you need to pay extra billing cost while you use GPRS to transmit data.

In the thesis, we provide a TCP connection environment with better benefit by combining the advantages of WLAN and GPRS. When a user builds a TCP connection, this connection environment will dynamically choose a wireless technology according to the environmental condition of the user to guarantee the highest transmission rate and the lowest billing cost while transmitting data. This connection environment also needs to decrease the delay time while switching wireless technologies.