TC redundancy

The two TC optimizations explained in section 3.7, optimizes the message size of TC messages and the set of nodes generating such messages. But the optimizations makes the topology understanding less robust. One may have multiple paths between nodes without knowing it.

To enable a more robust understanding of the topology, nodes can be set to announce more than just their MPR selector set in TC messages. A parameter TC_REDUNDANCY is introduced. TC messages are built based on this parameter. The following actions are taken based on the value of TC_REDUNDANCY:

• 0 - The advertised link set of the node is limited to the MPR selectors.

• 1 - The advertised link set of the node is the union of its MPR set and its MPR selector set.

• 2 - The advertised link set of the node is the full symmetric neighbor set.

If all nodes in a MANET has TC_REDUNDANCY set to 2, then all symmetric links in that network will be announced to all nodes. This means that all nodes, not just the nodes selected as MPRs, will generate TC messages.

A node has no knowledge of other nodes TC_REDUNDANCY settings, and it does not need to. Nodes without TC redundancy implemented can coexist with TC redundancy enabled nodes.