SYSTEM AND METHOD FOR SHORT RANGE COMMUNICATION USING ADAPTIVE CHANNEL INTERVALS

• US 20080232433A1
• Filed: 09/07/2007
• Published: 09/25/2008
• Est. Priority Date: 03/21/2007
• Status: Active Grant

• Current Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Original Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Inventors: McNew, Justin Paul, Dessouky, Khaled I., Moring, John Thomas
• Granted Patent: US 7,813,371 B2
• Time in Patent Office: Days
• US Class Current: 375/140
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover
• CPC Class Codes: H04W 28/18 Negotiating wireless communication parameters

Abstract

A system and method for data transmission on wireless discontinuous channels including a control/safety information (CSI) channel having a duty cycle, and a plurality of service channels. The system and method include: evaluating channel utilization of one or more of the channels; calculating an optimal CSI channel duty cycle responsive to the channel utilizations; adjusting the duty cycle of the CSI channel to the calculated optimal CSI channel duty cycle; broadcasting the optimal CSI channel duty cycle; and transmitting data during the optimal CSI channel duty cycle.

Claims

1. A method for data transmission on wireless discontinuous channels including a control/safety information (CSI) channel having a duty cycle, and a plurality of service channels, the method comprising:

evaluating channel utilization of one or more of the channels;

calculating an optimal CSI channel duty cycle responsive to the channel utilizations;

adjusting the duty cycle of the CSI channel to the calculated optimal CSI channel duty cycle;

broadcasting the optimal CSI channel duty cycle; and

transmitting data according to the optimal CSI channel duty cycle.

2. The method of claim 1, wherein the channels are discontinuous due to the transmitting unit switching to a different radio channel.

3. The method of claim 1, wherein the channels are discontinuous due to predetermined system access constraints.

4. The method of claim 1, wherein the optimal CSI channel duty cycle is broadcast in a service advertisement.

5. The method of claim 1, wherein evaluating channel utilization comprises evaluating channel utilization based on one or more of configuration parameters manually entered, data on the recent utilization of the CSI channel, data on the recent utilization of the service channels, current service channel allocation requests from applications utilizing the system, and relative priority of services on the CSI channel and the service channels.

6. The method of claim 1, further comprising imposing limits on the optimal CSI channel duty cycle.

7. The method of claim 1, further comprising increasing the optimal CSI channel duty cycle based on a high utilization of the CSI channel.

8. The method of claim 1, further comprising decreasing the optimal CSI channel duty cycle based on a high utilization of one or more of the service channels.

9. The method of claim 1, further comprising estimating the channel utilization of the CSI channel based on an estimate of a fraction of the CSI channel interval that is currently being used for transmissions or is currently being unavailable for data delivery.

10. The method of claim 9, wherein estimating the channel utilization of the CSI channel comprises directly monitoring the CSI channel during CSI channel interval.

11. The method of claim 1, further comprising estimating the channel utilization of a service channel based on an estimate of a fraction of a service channel interval that is currently being used for transmissions or is currently being unavailable for data delivery.

12. The method of claim 11, wherein estimating the channel utilization of the service channel comprises one or more of the steps:

directly monitoring the service channel during a service channel interval, monitoring service channel loading during each service channel interval, and utilizing predefined information.

13. A system for data transmission on wireless discontinuous channels including a control/safety information (CSI) channel having a duty cycle, and a plurality of service channels, comprising:

a channel controller device including a first processor and a first memory configured to evaluate channel utilization of one or more of the channels, calculate an optimal CSI channel duty cycle responsive to the channel utilizations, adjust the duty cycle of the CSI channel to the calculated optimal CSI channel duty cycle, and broadcast the optimal CSI channel duty cycle; and

a plurality of participant devices, each participant device including a second processor and a second memory configured to receive the broadcast optimal CSI channel duty cycle and transmit data during the optimal CSI channel duty cycle.

14. The system of claim 13, wherein the channels are discontinuous due to the transmitting unit switching to a different radio channel.

15. The system of claim 13, wherein the channels are discontinuous due to predetermined system access constraints.

16. The system of claim 13, wherein the channel controller device is configured to broadcast the optimal CSI channel duty cycle in a service advertisement.

17. The system of claim 13, wherein the channel controller device is further configured to evaluate channel utilization based on one or more of configuration parameters manually entered, data on the recent utilization of the CSI channel, data on the recent utilization of the service channels, current service channel allocation requests from applications utilizing the system, and relative priority of services on the CSI channel and the service channels.

18. The system of claim 13, wherein the channel controller device is further configured to estimate the channel utilization of the CSI channel based on an estimate of a fraction of the CSI channel interval that is currently being used for transmissions or is currently being unavailable for data delivery.

19. The system of claim 13, wherein the channel controller device is located in a roadside unit.

20. The system of claim 13, wherein the channel controller device is located in a vehicular onboard unit.

21. A method for adaptive channel switching in a Wireless Access in Vehicular Environments (WAVE) system including a control/safety information (CSI) channel and a plurality of service channels, the method comprising:

calculating optimal channel switch timings based on utilization of the CSI channel and utilization of the plurality of service channels;

broadcasting the calculated optimal channel switching times in a service advertisement;

adjusting channel switch timings to the calculated optimal channel switch timings; and

transmitting data according to the optimal channel switch timings.

22. The method of claim 21, further comprising estimating the channel utilization of the CSI channel based on an estimate of a fraction of the CSI channel interval that is currently being used for transmissions or is currently being unavailable for data delivery.

23. The method of claim 21, further comprising estimating the channel utilization of a service channel based on one or more of the steps:

directly monitoring the service channel during a service channel interval, monitoring service channel loading during each service channel interval, and utilizing predefined information.