Coexistence timer mechanism for wireless communication systems

• US 9,137,816 B2
• Filed: 11/02/2012
• Issued: 09/15/2015
• Est. Priority Date: 03/04/2010
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Bhoopalam, Bharath, Krishnan, Shriram, Luthra, Manev, Van Horn, Peter, Hirsch, Olaf J
• Primary Examiner(s): Pham, Brenda H
• Application Number:
  US13/667,913
• Publication Number:
  US 20130058316A1
• Time in Patent Office: 1,047 Days
• Field of Search: 370/310, 370/349, 370/324, 370/350, 370/252, 370/329, 370/341
• US Class Current: 1/1
• CPC Class Codes: H04W 72/1215 for collaboration of different radio technologies

Abstract

A common coexistence timer can be implemented on collocated or proximate wireless radio devices so that timing information associated with scheduled communications of each of the wireless radio devices is communicated with a common time reference. The coexistence timer provides the common time reference for the wireless radio devices. A transmitting wireless radio device can calculate a difference time associated with the timing information of a scheduled communication and can provide the difference time to a receiving wireless radio device. The receiving wireless radio device can convert the difference time into a time format corresponding to the receiving wireless radio device'"'"'s local time reference. This can minimize interference between the collocated or proximate wireless radio devices, thus minimizing performance degradation, packet collision, and interference. Moreover, this also can eliminate timing errors due to the wireless radio devices using different timers operating at different frequencies or being synchronized to different crystals.

Claims

1. A first wireless network device comprising:

a processor; and

a communication unit communicatively coupled with the processor, the communication unit to;

receive a difference time from a second wireless network device communicatively coupled with the first wireless network device, wherein the difference time is derived from timing information associated with a scheduled communication of the second wireless network device;

determine a clock cycle of a first coexistence timer associated with the first wireless network device, wherein the clock cycle corresponds to a start of a communication interval of the first wireless network device;

determine a first time value and a timing relationship between a local timer of the first wireless network device and the first coexistence timer based at least in part on the clock cycle; and

reconstruct the timing information based at least in part on adding the difference time to the first time value.

2. The first wireless network device of claim 1, wherein the communication unit is further to:

add the first time value to the difference time to generate reconstructed timing information associated with the second wireless network device; and

schedule a communication of the first wireless network device based, at least in part, on the reconstructed timing information.

3. The first wireless network device of claim 2, wherein after generating the reconstructed timing information, the communication unit is to

populate a scheduling table with the reconstructed timing information.

4. The first wireless network device of claim 1, wherein the communication interval comprises at least one member selected from the group consisting of a Bluetooth slot time interval and a wireless local area network (WLAN) beacon time interval, and

each clock cycle of the first coexistence timer comprises one member selected from the group consisting of a predetermined number of Bluetooth slot time intervals and a predetermined number of WLAN beacon intervals.

5. The first wireless network device of claim 1, wherein the communication unit is further to:

reconstruct the timing information in terms of the local timer based at least in part on the timing relationship.

6. The first wireless network device of claim 1, wherein when the first wireless network device is associated with a plurality of communication networks, the communication unit is further to:

store a timing relationship between the first coexistence timer and a local timer of the first wireless network device assigned for communication in the each of the plurality of communication networks.

7. The first wireless network device of claim 1, wherein the difference time is calculated by subtracting a second time value, of a second coexistence timer associated with the second wireless network device, from the timing information.

8. The first wireless network device of claim 7, wherein the first coexistence timer and the second coexistence timer are a common timer shared by the first wireless network device and the second wireless network device.

9. The first wireless network device of claim 7, wherein the first coexistence timer and the second coexistence timer are separate, synchronized coexistence timers.

10. The first wireless network device of claim 1, wherein the timing information comprises at least one member selected from the group consisting of a start time of the scheduled communication, an end time of the scheduled communication, and a duration of the scheduled communication.

11. The first wireless network device of claim 1, wherein the first coexistence timer is configured to switch to a low power operating state when the first wireless network device switches to the low power operating state.

12. The first wireless network device of claim 1, wherein the first wireless network device comprises a first instance of the first coexistence timer and a second instance of the first coexistence timer,

the first instance of the first coexistence timer is synchronized with a sleep mode timer and is operational when the first wireless network device is in a low power operating state,

the second instance of the first coexistence timer is synchronized with an active mode timer and is operational when the first wireless network device is in an active operating state, and

the sleep mode timer operates at a lower frequency than the active mode timer.

13. The first wireless network device of claim 12, wherein

the communication unit is to is further to:

copy a value of the first instance of the first coexistence timer into the second instance of the first coexistence timer when the first wireless network device switches from the low power operating state to the active operating state; and

copy a value of the second instance of the first coexistence timer into the first instance of the first coexistence timer when the first wireless network device switches from the active operating state to the low power operating state.

14. The first wireless network device of claim 1, wherein the first wireless network device is a wireless local area network device and the second wireless network device is a Bluetooth device.

15. The first wireless network device of claim 1, wherein the first wireless network device is a Bluetooth device and the second wireless network device is a wireless local area network device.

16. The first wireless network device of claim 1, wherein the first wireless network device and the second wireless network device comprise at least one member selected from the group consisting of collocated on a common integrated circuit, collocated on a common circuit board, and implemented on distinct integrated circuits in close proximity to each other.

17. A first communication network device comprising:

a processor unit; and

a communication unit communicatively coupled with the processor unit, the communication unit to;

receive a difference time from a second communication network device communicatively coupled with the first communication network device, wherein the difference time is derived from timing information associated with a scheduled communication of the second communication network device;

determine a clock cycle of a coexistence timer associated with the first communication network device, wherein the clock cycle corresponds to a start of a communication interval of the first communication network device;

determine a time value of the coexistence timer and a timing relationship between a local timer of the first communication network device and the coexistence timer based at least in part on the clock cycle, wherein the coexistence timer provides a common time reference for the first communication network device and the second communication network device; and

reconstruct the timing information by adding the time value to the difference time.

18. The first communication network device of claim 17, wherein the communication unit is further to:

populate a scheduling table with reconstructed timing information of the scheduled communication of the second communication network device, wherein the scheduling table comprises scheduling information of the scheduled communication of the second communication network device; and

schedule communications of the first communication network device based at least in part on the scheduling table.

19. The first communication network device of claim 17, wherein,

the communication interval comprises at least one member selected from the group consisting of a Bluetooth slot time interval and a wireless local area network (WLAN) beacon time interval, and

each clock cycle of the coexistence timer comprises at least one member selected from the group consisting of a predetermined number of Bluetooth slot time intervals and a predetermined number of WLAN beacon intervals.

20. The first communication network device of claim 17, wherein the first communication network device is a wireless local area network device and the second communication network device is a Bluetooth device.

21. A method comprising:

receiving, at a first wireless network device, a difference time from a second wireless network device communicatively coupled with the first wireless network device, wherein the difference time is derived from timing information associated with a scheduled communication of the second wireless network device,

determining a clock cycle of a coexistence timer associated with the first wireless network device, wherein the clock cycle corresponds to a start of a communication interval of the first wireless network device;

determining a time value and a timing relationship between a local timer of the first wireless network device and the coexistence timer based at least in part on the clock cycle; and

reconstructing, at the first wireless network device, the timing information based at least in part on adding the difference time to the time value.

22. The method of claim 21, further comprising:

adding the time value to the difference time to generate reconstructed timing information associated with the second wireless network device; and

scheduling communications of the first wireless network device based, at least in part, on the reconstructed timing information.

23. The method of claim 21, wherein said reconstructing the timing information comprises:

reconstructing the timing information in terms of the local timer based at least in part on the timing relationship.

24. A non-transitory, machine-readable storage medium having instructions stored thereon, which when executed by a processor of a first network device, cause the first network device to:

receive a difference time from a second network device communicatively coupled with the first network device, wherein the difference time is derived from timing information associated with a scheduled communication of the second network device;

determine a clock cycle of a coexistence timer associated with the first network device, wherein the clock cycle corresponds to a start of a communication interval of the first network device;

determine a time value and a timing relationship between a local timer of the first network device and the coexistence timer based at least in part on the clock cycle; and

reconstruct the timing information by adding the time value to the difference time.

25. The non-transitory, machine-readable storage medium of claim 24, wherein the instructions executed by the processor cause the first network device to:

schedule communications of the first network device based, at least in part, on reconstructed timing information associated with the second network device.

26. The non-transitory, machine-readable storage medium of claim 24, wherein the instructions executed by the processor cause the first network device to:

reconstruct the timing information in terms of the local timer based at least in part on the timing relationship between the local timer and the coexistence timer.

27. A first wireless network device comprising:

a processor; and

a communication unit communicatively coupled with the processor, the communication unit to;

determine timing information of a scheduled communication of the first wireless network device;

determine a time value of a coexistence timer, wherein the coexistence timer provides a common time reference for the first wireless network device and a second wireless network device that is communicatively coupled with the first wireless network device;

determine a difference time associated with the timing information based at least in part on the time value; and

provide the difference time to the second wireless network device to indicate a timing associated with the scheduled communication, wherein the coexistence timer is configured to switch to a low power operating state when the first wireless network device switches to the low power operating state.

28. The first wireless network device of claim 27, wherein the communication unit is further to:

determine the difference time by subtracting the time value from the timing information.

29. The first wireless network device of claim 27, wherein the communication unit is further to:

determine a clock cycle of the coexistence timer, wherein the clock cycle corresponds to a start of a communication interval of the first wireless network device;

determine a number of communication intervals of the first wireless network device until a start time of the scheduled communication; and

determine the timing information based, at least in part, on the number of communication intervals and the clock cycle.

30. The first wireless network device of claim 27, wherein

the first wireless network device comprises a first instance of the coexistence timer and a second instance of the coexistence timer,

the first instance of the coexistence timer is synchronized with a sleep mode timer and is operational when the first wireless network device is in the low power operating state,

the second instance of the coexistence timer is synchronized with an active mode timer and is operational when the first wireless network device is in an active operating state, and

the sleep mode timer operates at a lower frequency than the active mode timer.

31. The first wireless network device of claim 30, wherein the communication unit is further to,

copy a value of the first instance of the coexistence timer into the second instance of the coexistence timer when the first wireless network device switches from the low power operating state to the active operating state;

and

copy a value of the second instance of the coexistence timer into the first instance of the coexistence timer when the first wireless network device switches from the active operating state to the low power operating state.

32. The first wireless network device of claim 27, wherein the first wireless network device and the second wireless network device comprise at least one member selected from the group consisting of collocated on a common integrated circuit, collocated on a common circuit board, and implemented on distinct integrated circuits in close proximity to each other.

33. The first wireless network device of claim 27, wherein

the first wireless network device is a wireless local area network (WLAN) device and the second wireless network device is a Bluetooth device, or

the first wireless network device is a Bluetooth device and the second wireless network device is a WLAN device.