Vehicle-to-vehicle communication apparatus, vehicle-to-vehicle communication system, and method of determining applicability of moving image information to an application program

• US 7,751,945 B2
• Filed: 07/27/2006
• Issued: 07/06/2010
• Est. Priority Date: 08/11/2005
• Status: Active Grant

• Current Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Original Assignee: Alpine Electronics Incorporated (Alps Alpine Co., Ltd.)
• Inventors: Obata, Kijuro
• Primary Examiner(s): Tran; Khoi
• Assistant Examiner(s): SAMPLE, JONATHAN L
• Application Number:
  US11/494,276
• Publication Number:
  US 20070038772A1
• Time in Patent Office: 1,440 Days
• Field of Search: None
• US Class Current: 701/1
• CPC Class Codes: G08G 1/161 Decentralised systems, e.g. inter-vehicle communication
• CPC Class Codes: H04W 56/00 Synchronisation arrangements

Abstract

In a vehicle-to-vehicle communication system, when moving image information is transmitted between vehicles, a delay time acquisition unit determines a delay time that occurs when the moving image information is transmitted from a first vehicle to a second vehicle, and an applicability determination unit determines whether the moving image information transmitted with such a delay time is applicable to an application program running on an in-vehicle apparatus installed in the second vehicle. This makes it possible to transmit only moving image information which is usable by the in-vehicle apparatus.

Claims

1. A vehicle-to-vehicle communication apparatus comprising:

a wireless communication unit configured to wirelessly transmit and receive moving image information;

a time delay acquisition unit configured to acquire predicted delay time information representing an estimated length of time required to transmit the moving image information from one vehicle to another vehicle via a vehicle-to-vehicle transmission performed by the wireless communication unit;

an allowable delay table memory in which there is stored table information indicating an allowable delay time determined for at least one application program which uses the moving image information, the allowable delay time representing an allowable length of time required to transmit the moving image information from one vehicle to another vehicle; and

an applicability determination unit configured to determine the applicability of the moving image information to the at least one application program based on whether the predicted delay time information representing an estimated length of time required to transmit the moving image information from one vehicle to another vehicle acquired by the time delay acquisition unit is less than or equal to the allowable delay time stored in the allowable delay table memory.

2. The vehicle-to-vehicle communication apparatus according to claim 1, further comprising:

an image quality acquisition unit configured to acquire image quality information associated with the moving image information when the moving image information is transmitted between vehicles by the wireless communication unit; and

an allowable image quality table memory in which there is stored table information indicating allowable image quality determined for the at least one application program which uses the moving image information,

wherein the applicability determination unit determines the at least one applicability of the moving image information to the application program, based on the predicted delay time information acquired by the time delay acquisition unit, the allowable delay time stored in the allowable delay table memory, the image quality information acquired by the image quality acquisition unit, and the table information stored in the allowable image quality table memory.

3. A vehicle-to-vehicle communication system for wirelessly transmitting and receiving moving image information between a first vehicle-to-vehicle communication apparatus installed in a first vehicle and a second vehicle-to-vehicle communication apparatus installed in a second vehicle,

the first vehicle-to-vehicle communication apparatus including:

a time delay acquisition unit configured to acquire predicted delay time information representing an estimated length of time required to transmit the moving image information from the first vehicle to the second vehicle; and

a wireless transmission unit configured to wirelessly transmit the predicted delay time information acquired by the time delay acquisition unit and the moving image information to the second vehicle-to-vehicle communication apparatus,

the second vehicle-to-vehicle communication apparatus including;

a wireless reception unit configured to receive the moving image information and the predicted delay time information transmitted from the wireless transmission unit;

an allowable delay table memory in which there is stored table information indicating an allowable delay time determined for at least one application program which uses the moving image information, the allowable delay time representing an allowable length of time required to transmit the moving image information from one vehicle to another vehicle; and

an applicability determination unit configured to determine the applicability of the moving image information received by the wireless reception unit to the at least one application program, based on whether the predicted delay time information representing an estimated length of time required to transmit the moving image information from the first vehicle to the second vehicle received by the wireless reception unit is less than or equal to the allowable delay time stored in the allowable delay table memory.

4. The vehicle-to-vehicle communication system according to claim 3, wherein the wireless transmission unit wirelessly transmits the moving image information together with the predicted delay time information acquired by the time delay acquisition unit to the second vehicle-to-vehicle communication apparatus.

5. The vehicle-to-vehicle communication system according to claim 3, wherein:

the first vehicle-to-vehicle communication apparatus further includes a request reception unit configured to receive a request for transmission of the moving image information, the request being issued by the second vehicle-to-vehicle communication apparatus;

the wireless transmission unit is configured to wirelessly transmit the moving image information to the second vehicle-to-vehicle communication apparatus when the request reception unit receives the request for transmission of the moving image information from the second vehicle-to-vehicle communication unit as a response to the wireless transmission of the predicted delay time information acquired by the time delay acquisition unit to the second vehicle-to-vehicle communication apparatus; and

the second vehicle-to-vehicle communication apparatus further includes a request transmission unit configured to wirelessly transmit the request for transmission of the moving image information to the first vehicle-to-vehicle communication apparatus, when the applicability determination unit determines that the moving image information is applicable to an application program.

6. The vehicle-to-vehicle communication system according to claim 5, wherein:

the request reception unit is configured to receive a request for transmission of the moving image information in a modified format, the request being generated when the applicability determination unit determines that predicted delay time information is greater than the allowable delay time and is transmitted from the second vehicle-to-vehicle communication apparatus;

the moving image acquisition unit is configured to modify at least one of an encoding method, a compression ratio, and a frame rate of the moving image information in accordance with the request for transmission of the moving image information in the modified format so as to reduce a delay time that occurs when the moving image information is transmitted from the first vehicle to the second vehicle, the request being received by the request reception unit;

the wireless transmission unit is configured such that after the wireless transmission of the predicted delay time information acquired by the delay time acquisition unit to the second vehicle-to-vehicle communication apparatus, if the request reception unit receives the request for transmission of moving image information in the modified format, the wireless transmission unit wirelessly transmits, to the second vehicle-to-vehicle communication apparatus, the moving image information in the format modified in terms of at least one of the encoding method, the compression rate, and the frame rate; and

the request transmission unit is configured such that when the applicability determination unit determines that the moving image information is not applicable to an application program, the request transmission unit wirelessly transmits the request for transmission of the moving image information in the modified format to the first vehicle-to-vehicle communication apparatus.

7. A method of determining the applicability of moving image information to an application program, comprising:

a first step in which a time delay acquisition unit included in a first vehicle-to-vehicle communication apparatus installed in a first vehicle acquires predicted delay time information indicating an estimated length of delay time required to transmit the moving image information from the first vehicle to a second vehicle;

a second step in which a wireless transmission unit included in the first vehicle-to-vehicle communication apparatus transmits the moving image information together with the predicted delay time information acquired in the first step to a second vehicle-to-vehicle communication apparatus installed in the second vehicle;

a third step in which a wireless reception unit included in the second vehicle-to-vehicle communication apparatus receives the moving image information and the predicted delay time information transmitted in the second step; and

a fourth step in which an applicability determination unit included in the second vehicle-to-vehicle communication apparatus determines the applicability of the moving image information received in the third step to the application program based on whether the predicted delay time information representing an estimated length of time required to transmit the moving image information from the first vehicle to the second vehicle received in the third step is less than or equal to an allowable delay time determined for an application program which uses the moving image information, the allowable delay time representing an allowable length of time required to transmit the moving image information from the first vehicle to the second vehicle.

8. A method of determining the applicability of moving image information to an application program, comprising:

a first step in which a time delay acquisition unit included in a first vehicle-to-vehicle communication apparatus installed in a first vehicle acquires predicted delay time information indicating an estimated length of time required to transmit the moving image information from the first vehicle to a second vehicle;

a second step in which a wireless transmission unit included in the first vehicle-to-vehicle communication apparatus transmits the predicted delay time information acquired in the first step to a second vehicle-to-vehicle communication apparatus installed in the second vehicle;

a third step in which a wireless reception unit included in the second vehicle-to-vehicle communication apparatus receives the predicted delay time information transmitted in the second step;

a fourth step in which an applicability determination unit included in the second vehicle-to-vehicle communication apparatus determines the applicability of moving image information, which will be transmitted from the first vehicle-to-vehicle communication apparatus, to the application program based on whether the predicted delay time information received in the third step is less than or equal to an allowable delay time determined for an application program which uses the moving image information;

a fifth step in which, when the determination in the fourth step is that the moving image information is applicable to the application program, a request transmission unit included in the second vehicle-to-vehicle communication apparatus transmits a request for transmission of the moving image information to the first vehicle-to-vehicle communication apparatus;

a sixth step in which a request reception unit included in the first vehicle-to-vehicle communication apparatus receives the request for transmission of the moving image information transmitted in the fifth step; and

a seventh step in which when the request for transmission of the moving image information is received in the sixth step, the wireless transmission unit included in the first vehicle-to-vehicle communication apparatus transmits the moving image information to the second vehicle-to-vehicle communication apparatus.

9. The method of determining the applicability of moving image information to an application program according to claim 8, further comprising:

an eighth step in which when the determination in the fourth step is that the moving image information is not applicable to the application program because the predicted delay time information representing the estimated length of time required to transmit the moving image information from the first vehicle to the second vehicle is greater than the allowable delay time determined for the application program, the request transmission unit included in the second vehicle-to-vehicle communication apparatus transmits a request for transmission of the moving image information in a modified format to the first vehicle-to-vehicle communication apparatus;

a ninth step in which the request reception unit included in the first vehicle-to-vehicle communication apparatus receives the request for transmission of the moving image information in the modified format transmitted in the eighth step;

a tenth step in which a moving image acquisition unit included in the first vehicle-to-vehicle communication apparatus modifies at least one of an encoding method, a compression ratio, and a frame rate of the moving image information in accordance with the request for transmission of the moving image information in the modified format received in the ninth step so as to reduce a delay time that occurs when the moving image information is transmitted from the first vehicle to the second vehicle; and

an eleventh step in which the wireless transmission unit included in the first vehicle-to-vehicle communication apparatus transmits the moving image information acquired as the result of the process performed in the tenth step to the second vehicle-to-vehicle communication apparatus.