Understanding existing algorithms and finding the problems stated and addressed. Using low duty-cycle is the most common technique to extend the system lifetime in WSNs. However, it also implies limited throughput and long delay and the penalty is even higher under variable traffic patterns. In this project, we present MAC, a hybrid CSMA/TDMA MAC that adapts to variable/bursty traffic. With light load, iQueue-MAC uses a contention-based CSMA mechanism that provides low delay with scattered transmissions. When traffic increases, detected by a forming backlog in the sender, MAC changes to a contention-free TDMA mechanism allocating transmission slots. Thus, iQueue-MAC mitigates packet buffering and reduces packet delay, combining the best of TDMA and CSMA. Finally we compare the performance of the existing & the proposed system. The parameters such as throughput, packet delivery ratio, delay are also compared.We have proposed a novel energy efficient MAC protocol. This protocol has been modeled using time Petri nets and validated using NS2 tool. The simulation experiments undertaken on several network topologies of wireless sensor networks showed the effectiveness of MAC protocol in terms of energy consumption and latency.