The traditional TCP congestion control mechanism encounters a number of new
problems and suffers a poor performance when the IEEE 802.11 MAC protocol is
used in multihop ad hoc networks. Many of the problems result from medium
contention at the MAC layer. In this paper, I first illustrate that severe
medium contention and congestion are intimately coupled, and TCP s congestion
control algorithm becomes too coarse in its granularity, causing throughput
instability and excessively long delay.