System and Method of Vehicular Wireless Communication

• US 20070299571A1
• Filed: 11/08/2005
• Published: 12/27/2007
• Est. Priority Date: 11/08/2004
• Status: Active Grant

• Current Assignee: Toyota Motor Corporation, Regents of the University of California (University of California)
• Original Assignee: Toyota Motor Corporation
• Inventors: Mak, Tony, Sengupta, Raja, Laberteaux, Kenneth
• Granted Patent: US 8,116,959 B2
• Time in Patent Office: Days
• US Class Current: 701/24
• CPC Class Codes: G08G 1/096716 where the received information does not generate an automatic action on the vehicle control
• CPC Class Codes: G08G 1/096783 where the origin of the information is a roadside individual element
• CPC Class Codes: H04W 74/02 Hybrid access

Abstract

A system and method of vehicular wireless communication over a Dedicated Short Range Communication service band is provided. The system includes a vehicle having a navigation means, a processor, and a communication means for transmitting a message via a wireless communications link. The system includes a control channel for communication a safety communication and a service channel for communicating a non-safety communication. The control channel is subdivided into a contention-free period having a safety exchange interval of time for transmitting a safety communication and a contention period having a non-safety service interval of time for transmitting a non-safety communication. The system further includes an access point in communication with the vehicle via the communications link within region. The method includes the steps of determining if the vehicle is within communications range of the region, determining if the vehicle is registered with the access point, and if the vehicle is within the communications range of access point, determining if a current time is within the safety exchange interval, and transmitting the safety communication by each registered vehicle during the safety exchange interval at the predetermined time for each registered vehicle. The method further includes the steps of determining if the safety communication exchange by every registered vehicle is completed, and permitting the vehicle to leave the control channel if the safety communication exchange is complete, and determining if a current time is within a contention period, and transmitting the non-safety communication if the current time is within the contention period.

Claims

1. A method of vehicular wireless communication over a Dedicated Short Range Communication service band, said method comprising the steps of:

dividing the service band into a control channel for transmitting a safety communication, and a service channel for transmitting a non-safety communication;

subdividing the control channel into intervals of time, wherein one interval is a safety exchange interval and each registered vehicle transmits a safety communication at predetermined time during the safety exchange interval, and the predetermined time is determined by the access point;

determining if the vehicle is within communications range of an access point service region, wherein the access point service region is a geographic area containing an access point that transmits and receives non-safety communications to and from the vehicle in the access point service region;

determining if the vehicle is registered with the access point, if the vehicle is within the communications range of the access point, wherein the access point maintains a list of registered vehicles, and registering the vehicle with the access point if not registered;

determining if a current time is within the safety exchange interval in the contention free period of time in the control channel, and transmitting the safety communication by each registered vehicle during the safety exchange interval at the predetermined time for each registered vehicle, if the current time is within the safety exchange interval of the contention free period;

determining if the safety communication exchange by every registered vehicle is completed, and permitting the vehicle to leave the control channel if the safety communication exchange is complete; and

determining if a current time is within a contention period, and transmitting the non-safety communication if the current time is within the contention period.

2. A method as set forth in claim 1 further including the step of:

communicating a safety message on an ad hoc schedule if the vehicle is not within the access point service region.

3. A method as set forth in claim 1 wherein the safety message and non-safety message are transmitted via a broadcast over the Dedicated Short Range Communication service band by a radio.

4. A method as set forth in claim 1 further including the step of determining if the vehicle is leaving the region, and removing the vehicle from the list of registered vehicles if the vehicle is leaving the region.

5. A method as set forth in claim 1 wherein said step of dividing the control channel into intervals further includes the steps of:

defining a group management interval, wherein a coordinating access point performs management functions relating to managing the service access point and vehicles within the region; and

defining a service announcement interval, wherein the coordinating access point communicates a service offered by the service access point.

6. A method as set forth in claim 1 wherein said step of registering the vehicle within the region further includes the steps of:

updating the registered vehicle list by adding the vehicle to the registered vehicle list if determined that the vehicle is entering the region, or removing the vehicle from the registered vehicle list if determined that the vehicle is leaving the region.

7. A method as set forth in claim 1 wherein a shared coordinating access point coordinates each service access point within the region, and the coordinating access point that makes a collective service announcement for each service access point in the region during the contention free period.

8. A method as set forth in claim 1 wherein a shared coordinating access point coordinates each service access point within the region, and the shared coordinating access point makes a collective service announcement for each service access point in the region during or the contention period.

9. A method as set forth in claim 1 wherein a shared coordinating access point coordinates the service access points within the region, and each service access point makes its own service announcement during the contention free period.

10. A method as set forth in claim 1 wherein a shared coordinating access point coordinates the service access points within the region, and each service access point makes its own service announcement during the contention period.

15. A system as set forth in claim 1 wherein said contention free period of said control channel includes a safety exchange interval, and the contention period of said control channel includes a group management interval, and a service announcement interval.

11. A system of vehicular wireless communication over a Dedicated Short Range Communication service band within a region comprising:

a navigation means on the vehicle that is in communication with a global positioning system which includes a global positioning transceiver associated with the vehicle, and a global positioning signal transmitter in communication with the vehicle global positioning transceiver;

a processor on the vehicle that is in communication with said navigation means;

an input means in communication with said processor;

a user notification device operatively in communication with said navigation means for providing information to a vehicle operator;

a user manual input mechanism operatively in communication with said navigation means for transmitting information from the vehicle operator;

a communication means operatively in communication with said navigation means for transmitting a message over a channel on the Dedicated Short Range Communication service band via a wireless communications link, wherein the channel is divided into a control channel for communicating a safety communication and a service channel for communicating a non-safety communication, and the control channel is further subdivided into a contention free time period and a contention time period, and the contention free period and is subdivided into a safety exchange interval of time whereby each registered vehicle transmits a safety communication at a predetermined time during the safety exchange interval and the contention period is subdivided into a non-safety service interval of time;

an access point operatively in communication with the vehicle via said communications link within the access point service region, wherein the access point service region is a geographic area containing the access point and said access point registers the vehicle if the vehicle is within a communication range of the access point, and determines a predetermined time for each registered vehicle to transmit a safety communication during the safety exchange interval, and determines if the safety communication exchange by the registered vehicle is complete and permits the vehicle to leave the control channel if the safety communication is complete.

12. A system as set forth in claim 11 wherein:

said region is a circular area with a service access point co-located with a coordinating access point at a center of the region, and the coordinating access point transmits a first signal in an access point service range, a second signal in an access point safety exchange range, a third signal in an access point poll range, a fifth signal in an access point quiet range, and a sixth signal in an access point beacon range;

a first vehicle is located within the region and transmits a signal in a vehicle safety message range; and

a second vehicle is located within the region and transmits a signal in a maximum interference range.

13. A system as set forth in claim 12 wherein the sixth signal transmitted by the coordinating access point contains the start and stop time of the next contention free period.

14. A system as set forth in claim 11 wherein said vehicle transmits the safety communication on an ad-hoc basis when the vehicle is not registered with the access point.