Reliable Neighborcast: Coordination of Moving Groups

1. Reliable Neighborcast:Coordination of Moving Groups Nick Maxemchuk Columbia University

2. Outline • Applications - Moving Groups • Define Reliable Neighborcast • Overlays on Conventional RBP’s • Self Organizing Groups

3. Application - AutomobilesSensors -> Communications -> Coordination • Platooning: • Sensors: Warning, car in front • Communications: Share sensors, Dist. Anti-lock Brakes • Coordination: Platoons, Convoys • Highway merges and lane changes • Sensors: Cars in blind spot • Communications: 2 cars headed for same spot • Coordination: Signal Intent, Obtain Permission

4. Neighborcast Coordination: Communications with Nearby Vehicles • The group is different for every vehicle Unlike Broadcast or Multicast • The size of the group is different for cars and trucks • The group changes frequently

5. RNP Overlay on Overlapping RBP’s1-dimensional, overlapping lines -- highways Neighborhood: 3 cars in front and 3 cars behind Architecture: • One or more RBP protocols cover each location • Each vehicle participates in all RBP’s that cover its location RNP Objectives • Merge messages from multiple RBP groups • Provide RBP guarantees to each neighborhood General • At Most 2 RBP groups per vehicle

6. Not All Overlays are Equal • Large RBP’s -> Unneeded messages, • Long Xmission Dist. • Many Overlaps -> Duplicate messages • Extra Work for underlying RBP’s

7. The Effects of Mobility • Vehicles change neighborhoods and underlying broadcast groups • There is a delay to enter an RBP that depends on the protocol • Increasing the overlap eliminates the delay to enter a neighborhood • With Stationary Broadcast Groups, vehicles change broadcast groups more frequently than neighborhoods • A self-organizing algorithm to move broadcast groups

8. Moving Broadcast Groups Objectives: • Move Broadcast Groups while maintaining overlap • Split broadcast groups that are large enough to exceed minimum overlap • Join broadcast groups that must cover center of adjacent group Different rules for vehicles in regions 1, 2, 3 Each vehicle has limited knowledge

9. Reason for the Work • Improve Safety By providing warnings and coordination • Conserve Fuel By eliminating unnecessary stops • Reduce the need for new infrastructure, By increasing the capacity of existing facilities • Keep U.S. transportation industry competitive with Europe and Japan