The use of wireless network has been increased the popularity of mobile devices such as mobile etc. In such system, there are many type of problem created like hidden node problem which can be reduced to increase the efficiency of the network. Hidden terminals are intermediate sources which reduces the throughput of a wireless network if it applies MAC protocol. The RTS/CTS mechanism is a popular solution of this problem. RTS/CTS (Request to Send/Clear to Send) mechanism is a reservation scheme used in the wireless networks. It is used to reduce the frame collisions created due to the hidden node problem. Problem Statement: The IEEE 802.11 MAC protocol is the most implemented protocol for the wireless network. The IEEE 802.11 controls the access and share wireless medium within competing stations. The IEEE 802.11 DCF mode doubles the contention window size in lieu to improve the network performance but there are some collisions due to sudden change in CW rest to CWmin in channel. Approach: The research to date has been done only for the current number of active stations that have complex computations. A novel back-off algorithm is used for optimization of the contention window size. It uses the history based concept with packet lost.