Method
Each node implementing WRP keeps a table of routes and distances and link costs. It also maintains a 'message retransmission list' (MRL).
Routing table entries contain distance to a destination node, the previous and next nodes along the route, and is tagged to identify the route's state: whether it is a simple path, loop or invalid route. (Storing the previous and successive nodes assists in detecting loops and avoiding the counting-to-infinity problem - a shortcoming of Distance Vector Routing.)
The link cost table maintains the cost of the link to its nearest neighbors (nodes within direct transmission range), and the number of timeouts since successfully receiving a message from the neighbor.
Nodes periodically exchange routing tables with their neighbors via update messages, or whenever the link state table changes. The MRL maintains a list of which neighbors are yet to acknowledged an update message, so they can be retransmitted if necessary. Where no change in the routing table, a node is required to transmit a 'hello' message to affirm its connectivity.
When an update message is received, a node updates its distance table and reassesses the best route paths. It also carries out a consistency check with its neighbors, to help eliminate loops and speed up convergence.
Read more about this topic: Wireless Routing Protocol
Famous quotes containing the word method:
“Traditional scientific method has always been at the very best 20-20 hindsight. It’s good for seeing where you’ve been. It’s good for testing the truth of what you think you know, but it can’t tell you where you ought to go.”
—Robert M. Pirsig (b. 1928)
“A method of child-rearing is not—or should not be—a whim, a fashion or a shibboleth. It should derive from an understanding of the developing child, of his physical and mental equipment at any given stage, and, therefore, his readiness at any given stage to adapt, to learn, to regulate his behavior according to parental expectations.”
—Selma H. Fraiberg (20th century)
“The method of painting is the natural growth out of a need. I want to express my feelings rather than illustrate them. Technique is just a means of arriving at a statement.... I can control the flow of paint: there is no accident, just as there is no beginning and no end.”
—Jackson Pollock (1912–1956)