Overview

We have seen that OLSR functionality can be divided into three main modules: Neighbor sensing, multipoint relaying and link-state flooding. We have also seen that most control traffic is generated based on the set of repositories maintained by OLSR. These datasets are also updated dynamically based on received control messages.

Figure 3.14 displays an overview of the information repositories in OLSR and their relations to message processing, message generation and route calculation. Received HELLO messages trigger updates in the link set which again triggers updates in the neighbor set, which then again triggers recalculation of the MPR set. The 2 hop neighbor set is also updated based on received HELLO messages again triggering a recalculation of the MPR set. Finally the MPR selector set is updated according to information received in HELLO messages. Received TC messages triggers updates in the topology set while the MID set is updated upon receiving MID messages. All received messages will also be registered in the duplicate set if not already registered.

When generating HELLO messages, the link set, neighbor set and MPR set is queried. When generating TC messages, the MPR selector set is queried. When forwarding control traffic, the MPR selector set and the duplicate set is used.

Finally, route calculation is based on information retrieved from the neighbor set, the 2 hop neighbor set, the TC set and the MID set.

Figure: OLSR information repositories relation overview.