Sensor network devices have limited battery resources consumed by radio communication. Power saving is a critical issue for network devices. This paper is subjected to Ad hoc On-demand Distance Vector (AODV) & Bellman Ford routing protocol performance with IEEE 802.11 & IEEE 802.15.4 MAC protocol in random topology for 50 nodes & evaluated its performance. The authors investigated the energy consumption in transmit mode, receive mode, idle mode & residual battery by changing the MAC protocol & radio energy model through QualNet 6.1. The main interest of this paper is to identify the energy efficient radio energy model & MAC protocol.