Performance comparison of TCP NewReno and Vegas for IEEE 802.11e in multihop wireless networks

As wireless local area networks (WLAN) become ubiquitous and an integral part of data networks, they will also be increasingly used for applications ranging from standard Internet services like ftp to time bound multimedia applications, such as Voice (or Video) over IP (VoIP/VIP), HDTV etc. with strict latency, throughput or jitter restrictions. These applications on WLAN will also be more bandwidth and QoS demanding. Earlier versions of 802.11, and its variants used in WLAN deployment, did not have provisions for such QoS features. In order to minimize redesign in medium access control (MAC) protocol, QoS support has been incorporated in 802.11e that has provision to map QoS metric into existing 802.11 MAC parameters for priority assignment and fair scheduling. In this paper, we investigate the performance of TCP NewReno and Vegas in static multihop wireless network over AODV routing protocol and evaluate it over MAC protocol IEEE 802.11e. Throughput has been quantitatively evaluated for various network topologies such as chain, cross and grid using network simulator NS-2.29. Simulation results show that IEEE 802.11e with TCP Vegas over AODV can be used as one of the strong candidate for real time multimedia applications such as voice or video over IP in WLAN.