Rana Alhalimi
Optimized Link State Routing (OLSR) is a routing protocol used for Mobile Ad-Hoc Networks (MANET) routing. It is a best effort proactive protocol. Proactive protocols are characterized by all nodes maintaining routes to all destinations at all times through periodic exchange of protocol messages which gives it the advantage of having pre-computed routes available when needed. OLSR performs hop by hop routing by which each node uses its most recent information for routing.
OLSR is highly focused on reducing the overhead. And since OLSR works on periodic exchange of HELLO and TC messages, overhead reduction can be achieved by reducing the number of messages and the size of messages as well.
As a result of overhead reduction, information about QoS metrics is not propagated throughout the network. But with the rising popularity of multimedia applications and potential commercial usage of MANETs, QoS support in ad-hoc networks has become a very critical issue in the wireless area.
To support QoS, state information such as energy level, bandwidth or queue length should be available and manageable. But because the quality of wireless links changes quite frequently due to mobility and changes in surroundings added to that the bandwidth limitation, getting and managing such knowledge is a very complex task.
At the same time, since OLSR works on periodic exchange of HELLO and TC messages, QoS metric information might not be up to date at any instance of time. Therefore, nodes might have inaccurate information about other nodes in the network which might have a negative impact on the performance of the network.
The goal of this research is to quantify the accuracy of state information which is defined as how accurate is the available QoS metric information in terms of what their actual values are for different nodes, and what other nodes believe their values are. And devise techniques to reduce inaccuracies introduced by OLSR.