(英) |
Throughout the history of packet communication networks, congestion has been one of the problematic issues, which adversely affect network qualities, in terms of throughput, delay, delivery ratio, fairness, channel utility, and so on. In the internet, congestion is controlled by the end-to-end approach of the transport layer protocol, namely, Transmission Control Protocol (TCP). Due to multi-path fading, mobility, and so on, the end-to-end congestion control suffers from poor performance, implying the fact that the end-to-end congestion control does not operate well in multi-hop ad hoc networks. In this paper, we introduce a distributed congestion control scheme for multi-hop ad hoc networks. The scheme consists of congestion monitoring, inter-/intra-node rate signaling, and upper-/lower-layer rate control. Because the scheme operates in a distributed manner exploiting cross layer interactions, it can promptly react to the wireless channel dynamics. The simulation results show that our scheme can significantly improve traffic performance in terms of delivery ratio and delay. |