Page 1 of Fisheye State Routing (FSR) G. Pei, M. Gerla, Tsu-Wei Chen, "Fisheye State Routing: A Routing Scheme for Ad Hoc Wireless Networks," IEEE ICC 2000, vol. 1, pp Presented by Pasi Maliniemi

Page 2 of Presentation outline Fisheye vision Fisheye State Routing (FSR) Routing technique comparison FSR Simulation Results FSR - Summary References

Page 3 of Fisheye vision Fish do have 360° (or almost) vision. Fishes (and humans) do have a higher concentration of optic nerves close to they focal point than elsewhere in they eye. As a result fisheye captures with high detail the points near the focal point

Page 4 of Fisheye vision Fisheye View of Polaris. Dennis Anderson (2002)

Page 5 of Fisheye State Routing (FSR) For routing this approach translates into an accurate information in the immediate neighborhood of a node and less detail as the distance increases. FSR is similar to link state (LS) routing in that each node maintains a view of the network topology with a cost for each link. In LS routing link state packets are flooded into the network whenever a node detects a topology change.

Page 6 of Fisheye State Routing (FSR) In FSR nodes maintain a topology table (TT) based on the up-to-date information received from neighboring nodes and periodically exchange it with their local neighbors. For large networks in order to reduce the size of the routing update messages the FSR technique uses different exchange periods for different entries in the routing table. Relative to each node the network is divided in different scopes.

Page 7 of Scopes of FSR hop 2 hops 3 or more hops

Page 8 of Routing technique comparison

Page 9 of Message Reduction in FSR :{1} 1:{0,2,3} 2:{5,1,4} 3:{1,4} 4:{5,2,3} 5:{2,4} TTHOP 0:{1} 1:{0,2,3} 2:{5,1,4} 3:{1,4} 4:{5,2,3} 5:{2,4} TTHOP 0:{1} 1:{0,2,3} 2:{5,1,4} 3:{1,4} 4:{5,2,3} 5:{2,4} TTHOP Entries in black are exchanged more frequently

Page 10 of Simulation Results

Page 11 of Simulation Results

Page 12 of FSR - Summary Routing table entries for a given destination are updated, i.e. exchanged with the neighbors, with progressively lower frequency as distance to destination increases The further away the destination, the less accurate the route As a packet approaches destination, the route becomes progressively more accurate

Page 13 of FSR - Summary Benefits °Scales well to large network sizes °Control traffic overhead is manageable Problems °Route table size still grows linearly with network size °As mobility increases routes to remote destinations become less accurate °What happens if the target node is out of the scope of all nodes in the source nodes scope

Page 14 of References G. Pei, M. Gerla, Tsu-Wei Chen, "Fisheye State Routing: A Routing Scheme for Ad Hoc Wireless Networks," IEEE ICC 2000, vol. 1, pp Carlos Pomalaza-Ráez, Ad Hoc Networks - course material, University of Oulu