System and method for short range communication using adaptive channel intervals

• US 7,813,371 B2
• Filed: 09/07/2007
• Issued: 10/12/2010
• Est. Priority Date: 03/21/2007
• Status: Active Grant

• Current Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Original Assignee: Kapsch TrafficCom AG (Datax Handelsgmbh)
• Inventors: Moring, John Thomas, McNew, Justin Paul, Dessouky, Khaled I.
• Primary Examiner(s): Moe, Aung S
• Assistant Examiner(s): ELLIOTT IV, BENJAMIN H
• Application Number:
  US11/852,054
• Publication Number:
  US 20080232433A1
• Time in Patent Office: 1,131 Days
• Field of Search: 370/264, 370/270, 370/315, 370/328, 370/329, 370/332, 370/339, 370/432, 370/433, 340/905, 375/346, 375/358, 375/267, 701/24, 701/205, 701/301, 701/302, 455/41.2, 455/512, 455/515, 455/24, 455/205, 455/301, 455/302, 455/62, 455/509, 455518-521
• US Class Current: 370/431
• 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 to a plurality of units 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 wireless discontinuous channels by directly monitoring the one or more wireless discontinuous channels;

calculating a single optimal CSI channel duty cycle responsive to the channel utilizations, wherein the single optimal CSI channel duty cycle is shared by all of the plurality of units to transmit data;

adjusting the duty cycle of the CSI channel to the calculated single optimal CSI channel duty cycle to be shared by all of the plurality of units to transmit data;

broadcasting the single optimal CSI channel duty cycle to all of the plurality of units; and

transmitting data according to the single optimal CSI channel duty cycle.

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

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

4. The method of claim 1, wherein the single 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, 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 single optimal CSI channel duty cycle.

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

8. The method of claim 1, further comprising decreasing the single 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 a 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 the 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 wireless discontinuous channels, calculate a single optimal CSI channel duty cycle responsive to the channel utilizations, adjust the duty cycle of the CSI channel to the calculated single optimal CSI channel duty cycle, and broadcast the single 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 single optimal CSI channel duty cycle and transmit data during the single optimal CSI channel duty cycle, wherein the channel controller device is configured to evaluate the channel utilization by directly monitoring the one or more channels.

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

15. The system of claim 13, wherein the wireless discontinuous 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 single 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 a 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 a 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 for a plurality of mobile units, based on recent history utilization of the CSI channel and recent history utilization of the plurality of service channels;

broadcasting the calculated optimal channel switching times to all of the plurality of mobile units, in a service advertisement;

adjusting channel switch timings to the calculated optimal channel switch timings to be shared by all of the plurality of mobile units to transmit data; 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 a 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.