Proposal of a base station diversity technique based on TCP performance

The performance of TCP degrades rapidly in wireless communications environment, because TCP misunderstands the segment loss which is occurred by transmission errors as a network congestion. As improvement technique for TCP, we propose a new cellular system. In our proposed system, it supports a base station diversity technique, and a wireless terminal evaluates its own wireless environment and TCP performance. When the received signal power of a wireless terminal is small, the performance of TCP deteriorates under the influence of transmission errors. Then the wireless terminal with small received signal power connects to two or more base stations, in order to maintain the good performance of TCP. And it receives multiple frames of the same data from some base stations, and it performs the maximum likelihood ratio combining and decodes data. It seems that use of a base station diversity is effective also as a provision not only against decrease of received signal power but the fading, and the performance of TCP improve. In this paper, we evaluate the characteristics of TCP in the proposed base station diversity system, and it is shown clearly that the proposed system improves the performance of TCP greatly.