All the simulation works are done in ns2: the network simulator. We chose ns2 because it is free and open source, we can download from internet and modify the source code. We can use the trace file to search every packet at every hop. Most important, the AODV and DSR routing protocol have been implemented.
	Three metrics are used to compare the improvement:
	first is dropped packets, one is packets dropped because of no route, this is one we mostly focus on because it caused by link breakage. The other is total packet dropped, there is other reasons cause packet dropped, for example the interface queue is full.
	Second is the control message increase: for control message, each hop is counted as one. This is the overhead metric.
	Third is the hop count ratio: the ratio between actual total hop count with the total optimal hop count.
	Simulation parameters, used parameters published in mobicom 98 paper.
	50 mobile nodes in a 1500x300 meters area, 4 packet per second, 900 second simulation time.