Abstract: In order to improve the comprehensive performance of network, this paper fully consided the influence factor at the data link layer and network layer, compared and analysed of switching methods in the different Mac access protocol, selected an appropriate routing and access protocol for Ad Hoc. Simulating the scene based on Mac layer of 802. lla and 802. 11Ext routing in NS-2,the paper fully analyzed and summarized AODV protocol performance about normalized routing load and route discovery frequency and end-to-end average delay and packet delivery ratio. The results show that 802. 11Ext has many obvious advantages, it is more stable and suitable for mobile network.

Key words: Mobile Ad Hoc nctwork(MANETs) , Routing protocol, 802. 11, NS-2