Regional gossip routing for wireless ad hoc networks

One of the key challenges in ad hoc networks is the development of dynamic and efficient routing protocols. Some routing protocols use nodes´ positions, while some protocols are based on flooding essentially. Gossip based routing method had been used and re-investigated [Z. Haas et al., 2002] to reduce the number of messages: every node will forward a message based on a uniform probability p. The gossiping exhibits a bi-modal behavior [R. Meester et al., 1996]. Then, there is a threshold value p/sub 0/ such that, in sufficiently large random networks, the gossip message quickly dies out if p < p/sub 0/ and the gossip message spreads to all network if p > p/sub 0/. So ideally, we would set the gossiping probability close to p/sub 0/, thus save about 1- p/sub 0/ message overhead compared with the flooding. Gossiping still produces lots of unnecessary messages in regions that are far way from some line connecting the source to target nodes. We propose regional gossiping, in which essentially only nodes inside some region (derived from the source and target) will execute the gossiping protocol, and nodes outside the region will not participate in the gossiping at all. The region we select in our simulations are some ellipses using the source and target as foci. Our results show that, by using appropriate optimization heuristics, we can save up to 94% messages even compared with the global gossiping method.