Nancy Lynch Location - Free Routing Readings :

Today’s material is based on three papers, which describe related routing methods. All of these methods proceed by defining virtual coordinates for the nodes, which are approximations to real Euclidean coordinates but are not actually Euclidean coordinates. These virtual coordinates are defined by means of hop-count distances from certain “landmark” (or “beacon”, or “perimeter”) nodes. The nodes are not assumed to have GPS, or other sources of real coordinates—except possibly for the special perimeter nodes. Once the coordinates are defined, they are used for routing in simple greedy-style algorithms: keep forwarding the packet in the direction of the (virtual) coordinates of the destination.