Sentient Transportation SystemsSlide 2Drivers domain – NavigationHow do nodes communicate?Drivers domain – Congestion ControlInter-vehicle communication – MANET (Mobile Ad hoc Network)Multicast in MANET - ApproachesRISP (Receiver-Initiated Soft-State Probabilistic multicasting protocol)ExampleRISP – ConclusionInfotainmentChallenges in attaining infotainment:The middlewareCharacteristics Of MiddlewareFinding obstacles in vehicles pathPassenger domain – InfotainmentSlide 17Other uses of Sensors in the SystemTHANK YOUSentient Transportation Systems[Using sensor networks for building a full fledged transportation system for a township]Mobile Computing ClassCEN 5531Fall 2006Sundara DinakarMoumita GhoshShreyas DubeSentient Transportation SystemsSentient SystemsSentient Transportation SystemsIntegration of application areas:–"Drivers Domain“NavigationRoad and traffic information–"Passenger Domain“EntertainmentInformation on vehicle performanceNice driving experienceDrivers domain – NavigationBefore a journey, vehicles are notified about the virtual circuit (GPS ) waypoint information, vehicle builds RTImage (real-time perception)The cooperation between vehicles is critical to avoid collisions (through sensors)CORS (Continuously Operating Reference Stations)A Dead-Reckoning (DR) system kicks in to complement the GPS systemHow do nodes communicate?City divided into zones–Event based communication between vehicles–Using publisher subscriber model–Vehicles have filtersDrivers domain – Congestion ControlAccess Points collect information about congestion in zones from vehicles traveling thereDifferent Access Points from the same zone and different zones form a peer to peer network to exchange congestion informationVehicles record their speeds on each road, which when compared with the roads' speed limits gives an indication of the degree of congestion. On entering an area covered by a Wireless Access Point (AP), they report this data.Inter-vehicle communication – MANET (Mobile Ad hoc Network)Ad hoc networks operate without a fixed infrastructureMulti-hop transmissionIssues: –Limited power–Frequently changing topologyMulticast in MANET - ApproachesTree based–Group of core nodes run a multicast tree algorithm–Topology information needed–Not suitable for changing topologyMesh based–Uses a mesh to support multicast forwarding–Inefficient: Control overhead–Suitable for changing topologyFlooding based–No Control overhead–Consumes too much networkresourceRISP (Receiver-Initiated Soft-State Probabilistic multicasting protocol)The source node initiates a session by sending Beacon packetsUpon receiving a Beacon, receivers send Join_REQ packets to join the multicast session and keep the session aliveOn receiving the first Join_REQ packet, the source begins to send data packetsExampleLink failureLink additionRISP – ConclusionRISP introduces probabilistic forwarding and soft-state for making relay decisionsRISP can adapt to node mobility:–At low mobility, RISP performs similar to a tree-based protocol–At high mobility, it produces a multicast mesh in the networkSimulation results show that RISP has a lower delivery redundancy than mesh-based protocols, while it achieves higher delivery ratioThe control overhead is lower than other protocolsInfotainmentA pleasant driving experience.–Nearest pizza shop–Automatic Up/Down of window shuttersInformation about the vehicle–Air pressure in the wheel–Oil leak-Brake failureAchieved thru a well-planned sensory platform backed up with a powerful software framework.Challenges in attaining infotainment:Pervasive system that enables seamless integration of mobile devices Web service connectivity / basic navigation / vehicle diagnostics.Upgradeable, flexible and reliable.Harsh conditions – extreme temperatures / dust / vibrationsGraceful recovery from various faults.PerformanceNever cause a drain on the vehicle battery.Obedient to hard timing constraints regarding network bus responsiveness.Feature richness, Renewability, user interface.Prioritization of messagesThe middleware –CAN (Controller Area network) protocol stack to deliver messages between Electronic Control Units (ECU).Prioritization of messages.Characteristics Of MiddlewareDiagnosticsCommunication ServicesDevice Management (over the air and USB)Power ManagementSpeech ServiceMovement detection serviceMedia player functionalityGPS serviceFinding obstacles in vehicles pathVision sensors to find change in the color of the terrain.Creation of context awarenessPassenger domain – InfotainmentAutomotive Platform ComponentsPassenger domain – InfotainmentAutomotive Platform Components consist of:–Hardware–Drivers–Operating System–Application Framework–HMI framework–Application HMIOther uses of Sensors in the SystemStop at traffic signals (without human control)Use of RFID in rental cars( for inventory control)Use vehicles as Environmental Sensors, to collect large geospatial databaseTHANK