VEHICLE COMMUNICATION TERMINAL AND VEHICLE COMMUNICATION SYSTEM IN WHICH RADIO TRANSMISSIONS BY THE VEHICLE COMMUNICATION TERMINALS ARE CONTROLLED BY RADIO COMMUNICATION FROM BASE STATIONS

• US 20100299001A1
• Filed: 05/24/2010
• Published: 11/25/2010
• Est. Priority Date: 05/25/2009
• Status: Abandoned Application

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: SUZUKI, Tadao
• Application Number:
  US12/785,741
• Publication Number:
  US 20100299001A1
• Time in Patent Office: Days
• US Class Current: 701/2
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 48/02 Access restriction performed under specific conditions
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

In a vehicle communication system, a base station transmits radio signals conveying transmission control designation information to communication terminals of respective vehicles, and each vehicle communication terminal performs control of radio signal transmissions based on the most recently received transmission control designation information. Control may be specified for selected vehicle communication terminals or for all of the terminals, and can consist of selectively enabling/halting radio signal transmission, determining a maximum level of transmission power, etc. Information specifying a time point at which the transmission control is to commence may also be conveyed, and each vehicle communication terminal relays the received transmission control designation information to other vehicles, thereby increasing the effective service area of each base station.

Claims

1. A vehicle communication terminal conveyed by a motor vehicle, comprising a receiver circuit configured to receive externally transmitted radio signals and a transmitter circuit configured to transmit radio signals externally from said vehicle;

wherein said externally transmitted radio signals convey transmission control designation information relating to control of transmission operations of said transmitter circuit, and

said vehicle communication terminal comprises a transmission control circuit configured to be responsive to said transmission control designation information, when received by said receiver circuit, for controlling transmission operations of said transmitter circuit in accordance with said transmission control designation information.

2. A vehicle communication terminal as claimed in claim 1, wherein said transmission control designation information comprises transmission enable/halt information for selectively designating enabling and halting transmission of radio signals by said transmitter circuit, and wherein said transmission control circuit is configured to control said transmitter circuit to selectively enable and halt said transmission of radio signals by said transmitter circuit in accordance with said transmission enable/halt information.

3. A vehicle communication terminal as claimed in claim 1, wherein said transmission control designation information comprises transmission power-related information relating to a level of radio signal transmission power, and wherein said transmission control circuit is configured to control a level of transmission power of said transmitter circuit in accordance with said transmission power-related information.

4. A vehicle communication terminal as claimed in claim 3, wherein said transmission power-related information comprises maximum transmission power information specifying an upper limit level of power at which radio signals are to be transmitted by said transmitter circuit, and wherein said transmission control circuit is configured to control said transmitter circuit to limit a value of output power of said transmitter circuit in accordance with said upper limit specified by said maximum transmission power information.

5. A vehicle communication terminal as claimed in claim 1, wherein said transmission control designation information is transmitted together with control-time information expressing a time point for executing transmission control in accordance with said transmission control designation information by said transmission control circuit, and wherein said transmission control circuit is configured to initiate control of said transmitter circuit in accordance with said transmission control designation information at said time point expressed by said control-time information.

6. A vehicle communication terminal as claimed in claim 5, wherein

said control-time information specifies a time duration which is to elapse before said transmission control is to be initiated by said transmission control circuit,

said receiver circuit is configured to measure a time interval that has elapsed since a time point of receiving said transmission control designation information, and

said transmission control circuit is configured to commence execution of said transmission control in accordance with said transmission control designation information when said elapsed time interval coincides with said time duration specified by said control-time information.

7. A vehicle communication terminal as claimed in claim 5, comprising a current time measurement circuit for measuring a current time point, and wherein

said control-time information specifies a time point at which said transmission control is to be initiated by said transmission control circuit, and

said transmission control circuit is configured to commence execution of said transmission control in accordance with said transmission control designation information when said current time point coincides with said time point specified by control-time information.

8. A vehicle communication terminal as claimed in claim 1, wherein

said transmission control designation information comprises time stamp information expressing a time point at which said transmission control designation information was generated, and

said transmission control circuit is configured to utilize said time stamp information in performing transmission control of said transmitter circuit in accordance with said transmission control designation information.

9. A vehicle communication terminal as claimed in claim 8, comprising a current time measurement circuit for measuring a current time point, wherein said transmission control circuit is configured to modify utilization of currently received transmission control designation information when a difference between said time point expressed by said time stamp information of said currently received transmission control designation information and said current time point is judged to exceed a predetermined extent.

10. A vehicle communication system comprising

at least one vehicle communication terminal as claimed in claim 1, conveyed by a vehicle, and

at least one base station apparatus configured to transmit radio signals conveying said transmission control designation information;

wherein said receiver circuit of said vehicle communication terminal is configured to receive said radio signals transmitted by said base station apparatus, and wherein said transmission control circuit of said vehicle communication terminal is configured to perform transmission control of said transmitter circuit in accordance with said transmission control designation information conveyed by said radio signal from said base station apparatus.

11. A vehicle communication system as claimed in claim 10, wherein said base station apparatus comprises a roadside communication apparatus located adjacent to a road.

12. A vehicle communication system as claimed in claim 10, comprising a plurality of said vehicle communication terminals, conveyed by respective vehicles.

13. A vehicle communication system as claimed in claim 12, wherein each of said vehicle communication terminals conveyed by a vehicle

comprises an inter-vehicle communication circuit configured for effecting inter-vehicle communication to exchange information with a vehicle communication terminal conveyed by another one of said plurality of vehicles, and

receives, through said inter-vehicle communication, a radio signal transmitted from another one of said vehicle communication terminals conveying information previously received by said another vehicle communication terminal from a base station apparatus as a radio signal;

and wherein said received information comprises at least one of said transmission enable/halt information and said maximum transmission power information.

14. A vehicle communication system as claimed in claim 12, wherein

said transmission control designation information includes destination information, identifying at least one of said plurality of vehicle communication terminals as a vehicle communication terminal which is required to perform transmission control of said transmitter circuit thereof in accordance with said transmission control designation information, and

said transmission control circuit is configured for performing transmission control of said transmitter circuit in accordance with said transmission control designation information only when the vehicle communication terminal corresponding to said transmission control circuit is identified by said destination information contained in said transmission control designation information.