Wireless networks are inherently limited by battery power and bandwidth constraints. They are characterized by mobility, random changes in connectivity, fluctuations in channel and interference due to neighboring nodes etc. Due to these factors, packet loss of a wireless network is much more than that of a wired network, in which packet loss occurs mainly due to congestion in the network. Congestion in a network is characterized by delay and packet loss in the network. This leads to the requirement for congestion control mechanism. Several researchers proposed various congestion control mechanisms based on their observation.