Improved Congestion Control Mechanism Using Modified Hybrid-TCP in Mobile Ad-Hoc Neworks

Mobile Ad hoc networks (MANETs) is wholly a wireless community with a dynamic nature of position and network topology, which may change instantaneously with respect to time and application demand. Mobility factor of mobile nodes not only open gates for various applications but give big reason of packet loss. Transport Layer protocols like Transmission Control Protocol (TCP) have been designed for reliable communication. This paper addresses hybrid approach to overcome congestion situation and avoid packet loss in wireless networks. Proposed Modified Hybrid approach is the variant of Hybrid-TCP (H-TCP) and TCP Reno. Proposed Modified Hybrid - TCP variant consider the rate of increment parameter based on signal strength and noise factor to estimate a accurate retransmission time. Proposed Modified Hybrid-TCP is simulated using NS2 simulator and evaluated according to size of congestion window, packet delivery ratio, throughput with respect to mobility factor (speed of node). Performance observation concludes that proposed Modified Hybrid-TCP variant raises significant performance improvement during transmission over traditional TCP variants.