Wireless ad hoc network is a collection of wireless nodes that can dynamically organize itself into an arbitrary and temporary topology to form a network. This does not necessarily use any pre-existing infrastructure. These characteristics make ad hoc networks well suited for military activities, emergency operations and disaster management. Power optimization techniques are becoming increasingly important in wireless system design since the battery technology has not kept up with the demand of the mobile devices. Power control in wireless networks largely improves the capacity of the network and energy savings. The energy saving has been found to be improved by utilizing more number of intermediate hops between base source and destination. This paper aims to provide a survey of some existing approaches to transmission power control for wireless networks.