The Impact of Multihop Wireless Channel on TCP Throughput and Loss

— This paper studies TCP performance over multihop wireless networks that use the IEEE 802.11 protocol as the access method. Our analysis and simulations show that, given a specific network topology and flow patterns, there exists a TCP window size W ∗ , at which TCP achieves best throughput via improved spatial channel reuse. However, TCP does not operate around W ∗ , and typically grows its average window size much larger; this leads to decreased throughput and increased packet loss. The TCP throughput reduction can be explained by its loss behavior. Our results show that network overload is mainly signified by wireless link contention in multihop wireless networks. As long as the buffer size at each node is reasonably large (say, larger than 10 packets), buffer overflow-induced packet loss is rare and packet drops due to link-layer contention dominate. Link-layer drops offer the first sign for network overload. We further show that multihop wireless links collectively exh...

• Type: Conference
• Year: 2003
• Where: INFOCOM
• Authors: Zhenghua Fu, Petros Zerfos, Haiyun Luo, Songwu Lu, Lixia Zhang, Mario Gerla
• Keywords: Communications, INFOCOM 2003, Multihop Wireless Networks, TCP Window Size, Throughput