Optimized Link State Routing Protocol

The Optimized Link State Routing Protocol (OLSR) is a protocol to connect mobile ad-hoc networks, also sometimes called wireless mesh networks. It is a Link-state routing protocol. It collects data about which network members can communicate, and then calculates an optimized routing table.

The advantage of this approach is that connections are made quickly. The disadvantage is that the communication to discover network members occurs continuously. Also, calculation and memory burdens are continuing, and may be too heavy for small computers. The program is fairly large and complex.

OLSR is one of several solutions to this problem. Another is AODV, a distance vector routing protocol solving the same problem. Distance vector routing is simpler, requires less memory and calculation, but requires more delay, and when a route is needed, communication is much heavier. Another is Dynamic Source Routing, which substantially optmizes the network traffic. Another is Hazy Sighted Link State Routing Protocol, a careful mathematical optimization of proactive link-state features and reactive features. For other alternatives see the Ad hoc routing protocol list.

Further developmnent

see the german wikipedia page for the discussed schedule of the further development of OLSR.

Messages

OLSR make use of Hello messages to find its one hop neighbours and its two hop neighbours through there responses. The sender can then select its MPRs based on the one hop node which offer the best routes to the two hop nodes. Each node may also have a MS set which shows the show of nodes that have selected it as a MPR node.

External links

• http://www.ietf.org/rfc/rfc3626.txt Request for Comments on OLSR- the specification
• http://www.olsr.org/ downloadable code for OLSR on GNU/Linux, Windows, OS X, FreeBSD and NetBSD systems, with a great deal of documentation, including a very informative survey of related work.
• http://hipercom.inria.fr/olsr/ which includes this amusing Flash Demo.