Method and apparatus for vehicle-to-vehicle multi-hop broadcast communication

• US 20070117525A1
• Filed: 10/31/2006
• Published: 05/24/2007
• Est. Priority Date: 11/18/2005
• Status: Active Grant

• Current Assignee: Hitachi Solutions Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi, Ltd.
• Inventors: Osafune, Tatsuaki
• Granted Patent: US 8,289,186 B2
• Time in Patent Office: Days
• US Class Current: 455/99
• CPC Class Codes: G08G 1/161 Decentralised systems, e.g. inter-vehicle communication
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 4/026 using orientation information, e.g. compass
• CPC Class Codes: H04W 4/027 using movement velocity, acceleration information
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 4/46 for vehicle-to-vehicle communication [V2V]
• CPC Class Codes: H04W 48/08 Access restriction or access information delivery, e.g. discovery data delivery signalling during connection H04W76/00
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

The present invention relates to a method and apparatus for reducing the number of packets in a vehicle-to-vehicle multi-hop broadcast communication. The method determines a position data comprising a position, a velocity and a direction of a receiving vehicle (1, 2, 3, 4), receives a position data comprising position, velocity and direction from sending vehicles (1, 2, 3, 4), and calculates a relative position between the receiving vehicle (1, 2, 3, 4) and the sending vehicle (1, 2, 3, 4). Next, a density of vehicles is calculated from the calculated relative positions. The position data of the receiving vehicle (1, 2, 3, 4) is periodically sent, and the time for periodically sending the position data of the receiving vehicle (1, 2, 3, 4) is set in accordance with the calculated density of vehicles.

Claims

1. Method for vehicle-to-vehicle multi-hop broadcast communication comprising the steps of:

determining a position data comprising a position, a velocity and a direction of a receiving vehicle,

receiving position data comprising position, velocity and direction from sending vehicles,

calculating a relative position, a relative velocity and a relative direction between the receiving vehicle and the sending vehicle,

calculating a density of vehicles from the calculated relative positions, and

periodically sending the position data of the receiving vehicle, wherein a time for periodically sending the position data of the receiving vehicle is set in accordance with information respecting vehicles.

2. Method according to claim 1, wherein

the information respecting vehicles is the density of vehicles.

3. Method according to claim 1, wherein

the information respecting vehicles is the relative direction between the receiving vehicle and the sending vehicle.

4. Method according to claim 1, wherein

the receiving vehicle periodically retransmits the position data of the receiving vehicle and position data of the sending vehicle.

5. Method according to claim 1, wherein

the time for periodically sending the position data of the receiving vehicle and position data of the sending vehicles are set in accordance with the relative position between the receiving vehicle and the respective sending vehicle.

6. Method according to claim 1, wherein

retransmitting of the position data of the receiving vehicle and position data of the sending vehicles is stopped when the relative position between the receiving vehicle and the respective sending vehicle is larger than a predetermined threshold.

7. Method according to claim 1, wherein

when the receiving vehicle receives position data from the same sending vehicle twice within a predetermined time, the receiving vehicle decides upon the relative position to the sending vehicle about retransmitting the position data from the sending vehicle.

8. Method according to at least claim 1, wherein

the position data is a data packet comprising a data set which is a set of data which comprises at least a vehicle ID and a timestamp.

9. Method according to claim 1, wherein

the position data is a data packet comprising a data set which is a set of data which comprises at least a vehicles ID, a timestamp, an actual position, an actual speed and an actual direction of the vehicle.

10. Method according to claim 1 further has a receiving process, comprising the steps of:

receiving a data packet, determining from the data packet the number of the data sets included in the data packet, repeating for the number of data sets the following steps;

deciding if the data set is received for the first time by comparing a pair of vehicle ID and timestamp of the data set with a vehicle data database,

storing the data set in the vehicle data database upon the decision,

determining a time to send according to the relative distance between the sending vehicle and the receiving vehicle,

sending the data set when time to send is reached and deleting the data set from the vehicle data database.

11. Apparatus for vehicle-to-vehicle multi-hop broadcast communication comprising:

a position determining unit for determining position data comprising a position, a velocity and a direction of a receiving vehicle,

a receiving unit for receiving position data comprising position, velocity and direction from sending vehicles,

a relative calculating unit for calculating a relative position, a relative velocity and a relative direction between the receiving vehicle and each sending vehicle,

a density calculating unit for calculating a density of vehicles from the calculated relative positions, and

a sending unit for periodically sending the position data of the receiving vehicle, wherein the sending unit sets a time for periodically sending the position data of the receiving vehicle in accordance with information with respect to vehicles.

12. Apparatus according to claim 11, wherein

the in formation with respect vehicles is the density of vehicles.

13. Apparatus according to claim 11, wherein

the information with respect to vehicles is the relative direction between the receiving vehicle and the sending vehicle.

14. Apparatus according to claim 11, wherein

the sending unit of the receiving vehicle periodically retransmits the position data of the receiving vehicle and position data of the sending vehicles.

15. Apparatus according to claim 11, wherein

the sending unit sets the time for periodically sending the position data of the receiving vehicle and position data of the sending vehicles in accordance with the relative position between the receiving vehicle and the respective sending vehicle.

16. Apparatus according to claim 11, wherein

the sending unit stops retransmitting the position data of the receiving vehicle and position data of the sending vehicles when the relative position between the receiving vehicle and the respective sending vehicle calculated by the relative calculating unit is larger than a predetermined threshold.

17. Apparatus according to claim 11, wherein

when the receiving unit of the receiving vehicle receives position data from the same sending vehicle twice within a predetermined time, the receiving vehicle decides upon the relative position to the sending vehicle about retransmitting the position data from the sending vehicle.

18. Apparatus according to claim 11, wherein

the position data is a data packet comprising a data set which is a set of data which comprises at least a vehicle ID and a timestamp.

19. Apparatus according to claim 11, wherein

the position data is a data packet comprising a data set which is a set of data which comprises at least a vehicle ID, a timestamp, an actual position, an actual speed, and an actual direction of the vehicle.

20. Apparatus for vehicle-to-vehicle broadcast communication comprising:

a position determining unit for determining a position data of a receiving vehicle,

a receiving unit for receiving a data packet from a sending vehicle;

the data packet comprising a vehicle ID, a timestamp, and a position data of a sending vehicle,

a calculating unit for calculating a relative position between the receiving vehicle and the sending vehicle based on the position data of the sending vehicle and the position data of the receiving vehicle; and

a sending unit for re-sending the data packet received from the sending vehicle, after determining whether the data packet received from the sending vehicle is sent or not in accordance with the relative position calculated by the calculating unit.