Paging windows for power conservation in wireless networks

• US 8,073,470 B1
• Filed: 03/15/2006
• Issued: 12/06/2011
• Est. Priority Date: 01/31/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Jasper Wireless, Inc. (Cisco Systems, Inc.)
• Inventors: Collins, Daniel G., Gupta, Amit, Mohammed, Jahangir
• Primary Examiner(s): Appiah, Charles
• Assistant Examiner(s): HOLLIDAY, JAIME MICHELE
• Application Number:
  US11/377,902
• Time in Patent Office: 2,092 Days
• Field of Search: 455/458, 455/574
• US Class Current: 455/458
• CPC Class Codes: H04W 56/0015 one node acting as a reference for the others
• CPC Class Codes: H04W 68/00 User notification, e.g. alerting and paging, for incoming communication, change of service or the like
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Improved paging for wireless networks is disclosed. A wireless terminal clock is synchronized to a server clock. A paging window and a dormant window are set for communicating between the server and the wireless terminal using the synchronized time. The paging window and the dormant window are set using a set of instructions. During the paging window, a control channel for a cellular network is found by the wireless terminal, and a page is received from the server at the wireless terminal.

Claims

1. A method of paging for wireless networks comprising:

synchronizing a window clock of a wireless terminal to a server window clock, wherein the server window clock is separate from and is only synchronized periodically with the window clock of the wireless terminal;

determining whether the wireless terminal is in a traffic mode or a standby mode;

in the event that the wireless terminal is in standby mode, determining whether the window clock of the wireless terminal indicates that the wireless terminal is in a paging window or in a dormant window using a set of instructions, wherein the paging window has a duration at least as long as a duration from a start of a first paging slot to an end of a second paging slot between the wireless terminal and the server such that the paging window overlaps at least one paging slot between the wireless terminal and a base station, and wherein the dormant window has a duration greater than at least twice a period between the first paging slot and the second paging slot, wherein the period between the first paging slot and the second paging slot is based at least in part on a paging clock of the base station or a paging clock of the wireless terminal; and

in the event that the wireless terminal is in the dormant window, maintaining sleep of the circuitry of the wireless terminal and not waking up circuitry for any paging slots between the wireless terminal and the server;

in the event that the wireless terminal is in the paging window;

waking up circuitry to receive and to respond to the page;

determining a paging interval and a paging period, wherein the paging interval is based at least in part on a function of the wireless terminal identifier, a time, and a first paging period to distribute a paging load of the wireless network;

listening for the page during the paging period occurring at a time based at least in part on the paging interval;

receiving the page from the server at the wireless terminal if and only if a message is sent from the server to the wireless terminal; and

causing the circuitry of the wireless terminal to sleep.

2. A system of paging for wireless networks comprising:

a wireless terminal, wherein the wireless terminal includes a window clock;

a server for a cellular network, wherein the server includes a window clock, wherein the window clock of the server clock is separate from and is only synchronized periodically with the window clock of the wireless terminal; and

a processor; and

a memory coupled with the processor, wherein the memory is configured to provide the processor with instructions which when executed cause the processor to;

synchronize a clock of a wireless terminal to a server clock;

determine whether the wireless terminal is in a traffic mode or a standby mode;

in the event that the wireless terminal is in standby mode, determine whether the clock of the wireless terminal indicates that the wireless terminal is in a paging window or in a dormant window using a set of instructions, wherein the paging window has a duration at least as long as a duration from a start of a first paging slot to an end of a second paging slot between the wireless terminal and the server such that the paging window overlaps at least one paging slot between the wireless terminal and a base station, and wherein the dormant window has a duration greater than at least twice a period between the first paging slot and the second paging slot, wherein the period between the first paging slot and the second paging slot is based at least in part on a paging clock of the base station or a paging clock of the wireless terminal; and

in the event that the wireless terminal is in the dormant window, maintaining sleep of the circuitry of the wireless terminal and not waking up circuitry for any paging slots between the wireless terminal and the server;

in the event that the wireless terminal is in the paging window;

wake up circuitry to receive and to respond to the page;

determine a paging interval and a paging period, wherein the paging interval is based at least in part on a function of the wireless terminal identifier, a time, and a first paging period to distribute a paging load of the wireless network;

listen for the page during the paging period occurring at a time based at least in part on the paging interval;

receive the page from the server at the wireless terminal if and only if a message is sent from the server to the wireless terminal; and

cause the circuitry of the wireless terminal to sleep.

3. A system as recited in claim 2, wherein the set of instructions is set by the server.

4. A system as recited in claim 2, wherein the set of instructions is set by the wireless terminal.

5. A system as recited in claim 2, wherein the set of instructions is downloaded from the server to the wireless terminal.

6. A system as recited in claim 2, wherein the set of instructions is selected by a control signal.

7. A system as recited in claim 2, wherein the set of instructions includes a modulo function.

8. A system as recited in claim 2, wherein the set of instructions includes a bitwise-XOR function.

9. A system as recited in claim 2, wherein the set of instructions includes using a wireless terminal identifier as a parameter.

10. A system as recited in claim 2, wherein the set of instructions includes using a subscriber identifier as a parameter.

11. A system as recited in claim 2, wherein the set of instructions includes using the synchronized time as a parameter.

12. A system as recited in claim 2, wherein the set of instructions includes using a paging window periodicity as a parameter.

13. A system as recited in claim 2, wherein the set of instructions includes using a time length of the paging window as a parameter.

14. A system as recited in claim 2, wherein the set of instructions is a fixed set of instructions.

15. A system as recited in claim 2, wherein finding the control channel for the cellular network includes searching a list of control channels based on a location provided by GPS location information.

16. A system as recited in claim 2, wherein finding the control channel for the cellular network includes searching a list of control channels based on a location provided by the cellular network.

17. A system as recited in claim 2, wherein finding the control channel for the cellular network includes searching a list of control channels from all past locations.

18. A system as recited in claim 2, wherein finding the control channel for the cellular network includes searching a list of control channels based on anticipated locations.

19. A system as recited in claim 2, wherein finding the control channel for the cellular network includes searching a preprogrammed list of control channels.

20. A system as recited in claim 2, further comprising providing to a base station from the wireless terminal a location update.

21. A system as recited in claim 2, wherein synchronizing the wireless terminal clock to the server clock comprises synchronizing the wireless terminal clock to a first external time reference and synchronizing the server clock to a second external time reference, wherein the first and second external time references are synchronized with each other.

22. A system as recited in claim 2, wherein during the dormant window the clock rate is lowered to conserve power.

23. A system as recited in claim 2, wherein the processor is further configured to initiate communication with the server if no page has been received within a timeout interval.

24. A system as recited in claim 23, wherein the communication includes information to synchronize the wireless terminal window clock to the server window clock.

25. A system as recited in claim 23, wherein the communication includes information to recalibrate the wireless terminal window clock.

26. A system as recited in claim 23, wherein the communication includes information about pages to be sent to the wireless terminal.

27. A system as recited in claim 23, wherein the communication includes information to change one or more of the following:

the paging window, the dormant window, and the timeout interval.

28. A system as recited in claim 23, wherein the communication uses a packet switched network.

29. A system as recited in claim 23, wherein the communication uses one or more of the following:

a GPRS packet switched network, an EDGE packet switched network, and a WCDMA packet switched network.

30. A system as recited in claim 23, wherein the communication uses a paging network.

31. A system as recited in claim 23, wherein the communication uses a SMS paging network.