Throughput analysis of TCP on channels with memory

摘要

The focus of this paper is to analyze the relative sensitivity ofnthe bulk throughput performance of different versions of TCP, viz.,nOldTahoe, Tahoe, Reno, and New Reno, to channel errors that arencorrelated. We investigate the performance of a single wireless TCPnconnection in a local environment by modeling the correlated packetnloss/error process (e.g., as induced by a multipath fading channel) as anfirst-order Markov chain. A major contribution of the paper is a unifiednanalytical approach which allows the evaluation of the throughputnperformance of various versions of TCP. The main findings of this studynare that 1) error correlations significantly affect the performance ofnTCP, and in particular may result in considerably better performance fornTahoe and NewReno; and 2) over slowly fading channels which arencharacterized by significant channel memory, Tahoe performs as well asnNewReno. This leads us to conclude that a clever design of the lowernlayers that preserve error correlations, naturally present on wirelessnlinks because of the fading behavior, could be an attractive alternativento the development or the use of more complex versions of TCP