Transport protocols in wireless networks

摘要

It is well-known that TCP performs poorly in a wireless environment. This paper presents an empirical performance analysis of TCP on Cellular Digital Packet Data (CDPD) and Bluetooth. This analysis brings out the weaknesses of TCP in realistic conditions. We also present CentaurusComm, a message based transport protocol designed to perform well in low bandwidth networks and resource poor devices. In particular CentaurusComm is optimized to handle data exchanges consisting of short message sizes. The application used to perform all the experiments is typical of common applications that would use these protocols and network technologies. Typical mobile devices used in the experiments included Palm Pilots. We show that TCP performance on CDPD is very poor because of its low bandwidth and high latency. CentaurusComm outperforms TCP on CDPD. We show that on Bluetooth, which has higher bandwidth and lower latency than CDPD, both protocols perform comparably.