FRESH algorithm for efficient route discovery in MANET

FRESH:FResher Encounter Search

Principle:

Nodes keep a record of their most recent encounter times with all other nodes. Instead of searching for the destination, the source node searches for any intermediate node that encountered the destination more recently than did the source node itself. The intermediate node then searches for a node that encountered the destination yet more recently, and the procedure iterates until the destination is reached.

The performance of such a scheme will depend on the nodes’ mobility processes.

Introduction:

On-demand routing overhead can be broken down into two components: route discovery and route maintenance

(the route discovery represents up to 90% of the total routing overhead of AODV).

In this paper, the authors proposed an algorithm called FRESH to improves the performance of route discovery over omnidirectional approaches(by exploiting the history of last encounters between nodes).

Motivation: the history of last encounters between nodes contains valuable, but noisy information about the current network topology.

Packets descend along the age gradient.(thus far, I’m still confused)