不管是在有線還是無線網路環境中，網路傳輸協定已經廣泛的討論著。許多研究也被提出來改善網路傳輸協定以使其對網路上壅塞的情況能更快的反應，例如在網路連線中加入一些外部的訊息通知網路傳輸協定網路的狀態，或讓連線中容易發生壅塞的網路元件加入網路傳輸協定的壅塞控制機制。在GPRS/EGPRS及其他第三代無線網路中，無線網路控制元件會隨著無線網路使用者所在位置的無線電波情況以及系統目前能使用的資源，選擇適合的頻道編碼方式。當無線網路使用者處在較差的無線網路情況時，就必須花更多的編碼來處理錯誤偵測與修正，而使得實際能傳送的資料量減少，意即頻道的傳輸速度就下降；當無線網路使用者處在較好的無線網路情況時，就可以花較少的編碼來處理錯誤偵測與修正，而多傳一些資料，使得頻道傳輸速度增加。因此每一個無線網路使用者所使用的頻道傳輸速度是會隨著時間而變化不定的。
在這篇論文中我們針對網路傳輸協定提出了一個能隨著浮動的頻道傳輸速度改變窗口宣告的機制。這個機制將會使網路通訊協定中的窗口大小宣告參考目前網路傳輸速度來變動。而我們實驗模擬的結果顯示讓窗口宣告隨網路速度變化的機制比起傳統網路傳輸協定來說，將會降低網路上路由器中緩衝區的壅塞程度，減少封包在網路上的延遲時間，並能達到更好的網路效能。

TCP congestion control \cite{JacV.98} has been widely discussed on
the different networks under wireline or wireless environment.

Many research studies have been

raised to help TCP be more sensitive to congestion state of the

network by adding explicit notifications in TCP connection or

letting the intermediate in the network to join TCP congestion

control. In GPRS/EGPRS systems and other 3G cellular networks,

the radio network controller chooses among several channel coders

according to the signal to interference ratio. Hence,

the channel data rate that

an individual user experiences is time-dependent and variable.

In this paper, we propose a TCP window control mechanism that adapts

to the variable channel data rates.

Our simulations show that the rate adaptive

window adjustment scheme decreases the buffer occupancy and packet

transmission delay, and achieves better throughput utilization

when compared with the standard TCP Tahoe version and the Reno version.

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