CAT: Contention Aware Transport Protocol for IEEE 802.11 MANETs

In this paper, we present a Contention Aware Transport (CAT) protocol which is hop-by-hop, rate-based control, over IEEE 802.11 MANETs. CAT introduces a novel control metric, Sending Rate Control Factor (SRCF), for the congestion control. The SRCF considers the contention density which represents the degree of contention level experienced at a given node. In addition, to support reliable delivery, CAT uses a hop-by-hop acknowledgement scheme. The main purpose of CAT is, to find optimal traffic load that the channel bandwidth is fully utilized by sending rate adjustment while minimizing the packet losses from medium contention. The simulation results show that the network throughput achieved by CAT is around 10% and about 30% at peak point, higher than that of TCP and TCP-SACK.