The massive data traffic and the need for high speed wireless communication is increasing day by day corresponds to an exponential increase in the consumption of power by Information and Communication Technology (ICT) sector. Reducing consumption of power in wireless network is a challenging topic and has attracted the attention of researches around the globe. Many techniques like multiple-input multiple-output (MIMO), cognitive radio, cooperative heterogeneous communications and new network strategies such as heterogeneous networks, scattered antennas, multi-hop communication, etc., as well as radio and resource managing techniques like various sleep mode algorithms, cross layer optimization etc., have been proposed as solutions for this problem. In this paper, we present an overview of some of these techniques to optimize power in cellular network and MANET from various literatures. The green energy approaches as an alternate to grid power to optimize power consumption of BS is also reviewed. We also proposed a methodology to optimize power consumption in LTE-A network by jointly deploying RSs at cell edges.