Arunkumar Anand No 2, S7 ECE Vehicle-to-Vehicle Wireless Communication Protocol for Collision Warning Arunkumar Anand No 2, S7 ECE Seminar Presentation 2006 Dept. of Electronics & Communiactions. Govt. Engg. College, Wayanad. http://arunkumaranand.bizhat.com/seminar 28th September 2006

Contents Motivation Application Levels Overview of Vehicular Communications Needs and Assumptions Protocol for Vehicular Comm. Application Challenges State Transition Future Works Conclusion References

Accidents have been taking thousands of lives each year Motivation Accidents have been taking thousands of lives each year Study shows - “About 60% roadway collisions could be avoided if the operator of the vehicle was provided warning at least one-half second prior to a collision” (- US. Patent No. 5,613,039) Constraints of human drivers’ perception Line-of-sight limitation of brake light Large processing/forwarding delay for emergency events.

1. Line of Sight Limitation Constraints of human drivers’ perception 1. Line of Sight Limitation On foggy days What’s in front of that bus ? What’s behind the bend ? On rainy days Fig.1

Constraints of human drivers’ perception 2. Large forwarding delay for emergency events. Three Cars, namely Reaction time ranges from 0.7sec to 1.5sec Car A Car B Car C Animation. 1

Scope of this Paper Overview of Different Vehicular Communications Data Base Scope of this Paper Communication Hot Spots (DSRC) Petrol Pump, Workshop etc.. Satellite to Traffic Management Center (TMC) Vehicle (GPS) • Key Players – USDOT, AASHTO, auto companies • Working Group In Place – High level requirements defined – Defining data and communication requirements • Initiating DSRC Test Program ( V2V ) - Vehicle - Vehicle to - to - Roadside Vehicle (DSRC) ( DSRC) ( V2R ) Fig.2

Application Levels Traffic Safety can be improved if drivers have the ability to see further down the road. If traffic information was provided to Drivers, Police and other Authorities; roads would be safe and traveling on them would be more efficient Vehicle-to-Vehicle(V2V) and Vehicle-to-Roadside(V2R) Communication can bring out the following achievements. Presence of obstacles on road. Emergency Braking of a preceding vehicle. Information about Blind Crossing, School proximity, Railway crossing etc… Entries to Highways. High Speed Internet Access. Electronic Toll Collection. Parking Space locater in Cities. Nearest Petrol Pump, Workshop etc..

for a vehicle participating in V2V communication Needs and Assumptions for a vehicle participating in V2V communication Interested on Direction, Speed, Position etc… Is able to obtain its own geographical location and determine the relative positions on the road.(Digital Maps, GPS) Is equipped with at least one wireless transceiver

Protocol for Vehicular Comm. Unreliable wireless link Congested channel Versatile topology due to high mobility of vehicles Low Latency Dynamically form wireless loops Challenges and Requirements Technology for ITS especially for v2v and v2r communication Service rules for DSRC are developed by the ASTM DSRC is based on IEEE 802.11a technology 10m Min. Separation 1000m Max Range 1-54Mbps Data Rate 7 channels Channels QPSK OFDM Modulation 75MHz (5.850 – 5.925GHz) Bandwidth DSRC (Dedicated Short Range Communication)

Analyze a practical situation Animation. 2 Analyze a practical situation position speed intent… DSRC for cooperative vehicle information

DSRC for cooperative vehicle information Animation. 2 Who affects the most ? Not For me! position speed intent… DSRC for cooperative vehicle information For me!

Terms Abnormal Vehicle (AV) Emergency Warning Messages (EWM) A vehicle acts abnormally, e.g. deceleration exceeding a certain threshold, dramatic change of moving direction, major mechanical failure, etc. Emergency Warning Messages (EWM) Messages generated by an AV to warn other surrounding vehicles, which include the geographical location, speed, acceleration and moving direction of the AV.

Application Challenges <1> Requiring to support multiple co-existing AVs over a longer period of time Co-existing AVs: AVs whose existences overlap in time and whose transmissions may interfere with each other An AV can exist for an extended period of time Chain effects of emergency road situation Fig.3

Application Challenges <2> Differentiation of emergency events and elimination of redundant EWMs Unnecessary EWMs should be avoided so that the channel bandwidth can be better utilized for useful EWMs Fig.4

State transitions of AVs Eliminate redundant EWMs State transitions of AVs Each AV may be in one of three states: Initial AV: When an emergency event occurs to a vehicle, the vehicle becomes an AV and enters the initial AV state, transmitting EWMs following the rate decreasing algorithm. Non-flagger AV: nonparticipating in sending EWMs to the group on some conditions to eliminate redundant EWMs Flagger AV: resuming EWM transmissions at the minimum required rate.

State transitions of AVs (condition.) Transitions from Initial AV state to Non-flagger AV state: At least Talert duration has elapsed since the time when the vehicle became an initial AV. EWMs from one of the “followers” of the initial AV are being overheard; Transitions from Non-flagger AV to flagger AV sets a timer for a Flagger Timeout ( FT) duration. If it does not receive any EWMs from its followers when the FT timer expires, the non-flagger AV changes its state to flagger AV. Transitions from flagger AV to Non-flagger AV If a flagger AV receives EWMs from one of its followers, it will relinquish its flagger responsibility, becoming a non-flagger AV.

Examples of state transitions Fig. 5a Fig. 5b Fig. 5c

Examples of state transitions (cont.) Fig. 5d

Future Works USDOT Intelligent Transportation Systems (ITS) Program Vehicle manufacturers would install the technology in all new vehicles, beginning at a particular model year Full-scale deployment in both the vehicles and the roadside infrastructure will be made by 2008/9 Car2Car Communication Consortium ( www.car-to-car.org ) Non-profit organization initiated by European vehicle manufacturers. To create and establish an open European industry standard for Car2Car communication systems based on wireless LAN components and to guarantee European-wide inter-vehicle operability

Conclusion An Overview of Vehicular Comm. is given. Protocol of Vehicular Comm. Is discussed. Protocol Challenges are also analysed. Hi Buddy A new era is arriving where vehicles will communicate with each other, the devices within them, and also with the world; making the next generation of vehicles into communication hubs.

References [1] S. Biswas, "Vehicle-to-Vehicle Wireless Communication Protocols for Enhancing Highway Traffic Safety," Communications Magazine, IEEE Publication Date: Jan. 2006 Volume: 44, Issue: 1 page(s):74- 82 [2] X. Yang et al., " A Vehicle-to-Vehicle Communication Protocol for Cooperative Collision Warning,"Proc. 1st Annual Int’l. Conf. Mobile and Ubiquitous Syst: Networking and Services, 2004 [3] G.S Bickel, "Inter/Intra-Vehicle Wireless Communication" at http://userfs.cec.wustl.edu/~gsb1/index.html [4] Q. Xu, R. Sengupta, and D. Jiang, "Design and Analysis of Highway Safety Communication Protocol in 5.9 GHz Dedicated Short-Range Communication Spectrum," Proc. IEEE VTC, vol. 57, no. 4, 2003, pp. 2451–55 [5] C.Bettstetter  "Toward Internet-Based Car Communications: On Some System Architecture And Protocol Aspects" TUM, Germany [6] J. Zhu and S. Roy, "MAC for Dedicated Short Range Communications in Intelligent Transport Systems,"IEEE Commun. Mag., vol. 41, no. 12, 2003 [7] http://www.car-to-car.org/

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