Section: Contracts and Grants with Industry
The CELAR project has started in April 2004 for three years. Its aim is to enhance the demonstrator of mobile ad-hoc network MANET/OLSR, previously implemented with secured routing, quality of service (QoS), and an OLSR/OSPF gateway. This project is funded by CELAR (Centre d'Electronique de l'Armement, French MoD/DGA). This testbed allows CELAR to make demonstrations with a real mobile ad-hoc network, and evaluate the potential benefits of such a network in military tactical applications, with a special focus on performances and reliability. It is made up of 18 nodes: 10 OLSR routers and 8 terminals (VAIOs and iPAQs). Routers and terminals are equipped with 802.11b cards and measurements tools on Linux. They implement the OLSR routing protocol. Performance measurements have been done in various configurations including different traffic types, network topology and mobility (e.g., pedestrian and/or vehicle).
More precisely, this project addresses four topics :
secured routing : in a mobile ad-hoc network, the use of secured tunnels is not sufficient to protect routing against potential attacks. First, we have analyzed potential attacks against OLSR routing and we have precised our security goal. In the attacks, we also consider the case of compromised nodes in the network. These nodes have a certain knowledge of the network secret keys. In the case where the network does not encompass compromised nodes, we have design a security architecture which can counter most of the identified attacks except the wormhole attack. This security architecture is base on timestamping and signing message. For the case where there is compromised nodes in the network we have proposed various scheme to mitigate the effects of attacks in such a situation.
QoS management : it is more complex in mobile ad-hoc networks than in wired networks because of their high dynamicity, the presence of interferences and the limited resources. We propose an extension of OLSR conciliating both QoS support and optimized flooding. Flows having QoS requirements are source routed on the shortest path providing the requested bandwidth. Best effort flows are routed hop by hop and regulated by leaky buckets. Simulation results show that QoS flows receive a throughput close to this request and have a high delivery rate. Moreover, this extension supports node mobility : up to 20m/s with the default OLSR parameter values.
OLSR/OSPF gateway : the aim is to allow exchanges of routing information between an OLSR network and an OSPF network. As both routing procols are link based, the OLSR/OSPF gateway will take advantage of this similarity.
up-to-date version of OLSR : this CELAR testbed has been carried up on the OLSR version compliant with the RFC 3626.
The solution proposed for these four topics have been implemented on the testbed. Measurements made on this testbed are close to the simulations results. This MANET/OLSR testbed is frequently used in the exhibits organized by CELAR. It allows CELAR to demonstrate that MANET with OLSR routing are good candidates for tactical networks.