<FONT face=Verdana>Looking for usable gateway is a process

which brings the biggest overhead

in MANET accessing Internet. For controlling the routing overhead effectively

an accessing network overhead control algorithm

which based on gateway pheromone

is proposed in this paper according to the similar between ant searching path and mobile node searching gateway. By simulating the pheromone’s update process in ant colony algorithm

this algorithm uses information carried in RREP to update gateway pheromone. According to the pheromone density on the link

link bandwidth and delay

the node computes transmission probability and transmits the RREQ. This algorithm is simulated by NS2.29. The test result indicates that though it increases average delay appreciably

it reduces normalized routing overhead effectively and increases packet delivery radio. The validity of algorithm is validated.