Link set optimization

Due to the nature of the MPR selection, only nodes which are chosen as MPRs by one or more neighbors, needs to declare their link-state. In fact, these nodes need only declare the MPR selectors in the link-state messages. When this information is flooded to all nodes in the MANET, all nodes will have enough information to calculate shortest path routes to all hosts. The default OLSR setting is that a node only floods link-state messages if it is chosen as MPR by at least one neighbor, and it only announces its MPR selectors in these messages. In a topology as illustrated in figure 3.7 only the nodes selected as MPRs(gray nodes) by one or more neighbors will transmit link-state messages. One can easily see that this information, in addition to some neighbor-sensing scheme, will be sufficient to create a full understanding of the topology.

Figure: An OLSR routed network. The gray nodes are chosen as MPRs by one or more neighbor.