Wireless Communication and Wireless Networking is the popular research in this era. The combination of this is useful method for one step ahead to increase the life of human being. The motto of the research is to implement the protocol on Data-Link Layer, which is the WBAN stack protocol layer architecture, use to increase the life time of battery by energy saving. The novelty in the proposed method is to reduce energy consumption using the concepts of contention window which is adaptive to the different traffic conditions. The experimental result shows increase in Total Remaining Energy, Common Node Energy, Cluster Head Energy and BAN Coordinator Node Energy of Wireless Body Area Network. The proposed protocol is simulated in NS2 environment.