Throughput analysis of TCP on channels with memory

The focus of this paper is to analyze the relative sensitivity of the bulk throughput performance of different versions of TCP, viz,, OldTahoe, Tahoe, Reno, and New Reno, to channel errors that are correlated. We investigate the performance of a single wireless TCP connection in a local environment by modeling the correlated packet loss/error process (e.g,, as induced by a multipath fading channel) as a first-order Markov chain. A major contribut ion of the paper is a unified analytical approach which allows the evaluati on of the throughput performance of various versions of TCP, The main findi ngs of this study are that 1) error correlations significantly affect the p erformance of TCP, and in particular may result in considerably better perf ormance for Tahoe and NewReno; and 2) over slowly fading channels which are characterized by significant channel memory, Tahoe performs as well as New Reno. This leads us to conclude that a clever design of the lower layers th at preserve error correlations, naturally present on wireless links because of the fading behavior, could be an attractive alternative to the developm ent or the use of more complex versions of TCP.