Method and apparatus for periodically re-activating a mobile telephone system clock prior to receiving polling signals

• US 5,758,278 A
• Filed: 02/06/1996
• Issued: 05/26/1998
• Est. Priority Date: 02/07/1995
• Status: Expired due to Term

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Mobile Phones UK Limited (Nokia Corporation)
• Inventors: Lansdowne, Richard
• Primary Examiner(s): Pham, Chi H.
• Application Number:
  US08/595,976
• Time in Patent Office: 840 Days
• Field of Search: 455/38.3, 455/127, 455/343, 455/574, 340/825.44, 370/311
• US Class Current: 455/343.4
• CPC Class Codes: H04W 52/029 reducing the clock frequency of the controller
• CPC Class Codes: H04W 74/06 using polling
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A mobile telephone has a high frequency system clock and processing means. In a stand-by condition, when the telephone is not being used as such but is ready to receive incoming calls, polling signals are processed during a predetermined portion of a repeated periodic cycle. After completing cycle processing, the system clock is de-activated. However, it is not necessary to calculate a de-activation period. Re-activation occurs at a predetermined position within the repeated periodic cycle in anticipation of receiving the next polling signals.

Claims

1. A mobile telephone having a high frequency system clock and processing means, wherein said processing means is arranged to process polling signals received during a predetermined portion of a repeated periodic cycle, comprising:

means for de-activating said system clock after completing cycle processing, said cycle processing occurring during a cycle processing interval having a variable duration, and

means for re-activating said system clock at a predetermined position within said repeated periodic cycle in anticipation of receiving polling signals, said means for re-activating operating without regard for the duration of said cycle processing interval.

2. A mobile telephone according to claim 1, wherein said system clock oscillates at a frequency of between 5 megahertz and 20 megahertz.

3. A mobile telephone according to claim 1, wherein polling signals are received during a predetermined frame of a superframe multiplex.

4. A telephone according to claim 3, wherein each superframe includes from ten to fifty frame periods.

5. A telephone according to claim 4, wherein each frame period includes time allocation for transmission and time allocation for reception.

6. A telephone according to claim 1, wherein the system clock is de-activated when the telephone is in a stand-by condition ready to receive incoming calls.

7. A telephone according to claim 1, wherein the predetermined position within the repeated periodic cycle is determined with reference to a low frequency sleep clock.

8. A telephone according to claim 7, wherein a predetermined number of sleep clock pulses are counted to produce re-activation signals.

9. A telephone according to claim 7, wherein the sleep clock is calibrated with reference to the system clock and with reference to timing signals received from base stations.

10. A method for use in a mobile telephone of a type that comprises a system clock and a data processor coupled to the system clock, the data processor operating to periodically process polling signals during a polling signal processing interval, the polling signals being received during a predetermined portion of a repeated periodic cycle, comprising steps of:

de-activating the system clock at a termination of a polling signal processing interval, the polling signal processing interval being capable of having a duration that differs from a duration of a previous polling signal processing interval; and

re-activating the system clock at a predetermined position within the repeated periodic cycle prior to the receipt of a next polling signal to be processed, wherein the step of re-activating operates to re-activate the system clock without regard for a time that the previous polling signal processing interval was terminated.

11. A method according to claim 10, wherein the system clock oscillates at a frequency of between about 5 megahertz and about 20 megahertz.

12. A method according to claim 10, wherein polling signals are received during a predetermined frame of a superframe multiplex, and wherein each superframe includes from ten to fifty frames.

13. A method according to claim 12, wherein each frame includes a reception portion and a transmission portion.

14. A method according to claim 10, wherein the polling signal processing interval occurs when the telephone is in a stand-by condition ready to receive incoming calls.

15. A method according to claim 10, wherein the predetermined position within the repeated periodic cycle is determined with reference to a sleep clock having a lower frequency that the system clock.

16. A method according to claim 15, wherein the step of re-activating includes steps of:

counting a predetermined number of sleep clock pulses; and

generating a system clock re-activation signal after a predetermined number of sleep clock pulses have been counted.

17. A method according to claim 15, and further comprising a step of calibrating the sleep clock with reference to the system clock and with reference to timing signals received from an external transmitter.

18. A mobile telephone having a system clock that drives a data processor, wherein said data processor processes polling signals received during a predetermined portion of a repeated periodic cycle, comprising:

means for de-activating said system clock and said data processor after completing cycle processing, said cycle processing occurring during a cycle processing interval having a variable duration; and

means for re-activating said system clock and said data processor at a predetermined position within said repeated periodic cycle in anticipation of receiving polling signals, said means for re-activating being synchronized to said repeated periodic cycle and operating without regard for the duration of said cycle processing interval.