Reduced power sleep modes for mobile telephones

• US 5,991,635 A
• Filed: 12/18/1996
• Issued: 11/23/1999
• Est. Priority Date: 12/18/1996
• Status: Expired due to Term

• Current Assignee: Blackberry Limited
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Rydbeck, Nils R., Raith, A. Krister, Dent, Paul W., Sawyer, Francois
• Primary Examiner(s): LE, THANH C
• Application Number:
  US08/768,976
• Time in Patent Office: 1,070 Days
• Field of Search: 455/422, 455/38.1, 455/38.3, 455/507, 455/517, 455/550, 455/572, 455/574, 455/575, 455/343, 455/458
• US Class Current: 455/517
• 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

In a mobile radio-telephone system including at least one base station transmitting information to subscriber telephones indicating whether they are being called, a method comprising the steps of dividing a repetitive frame period into a number of sleep-mode slots, determining a sleep-mode slot number to be used for transmitting a call to a particular subscriber telephone using an assigned subscriber telephone number, transmitting a calling message in said determined sleep-mode slot including the assigned subscriber telephone number, repeating transmission of the calling message a number of times as determined by system loading and available capacity to transmit such calls, and transmitting an indication of the number of repeated transmissions capacity and loading currently permits.

Claims

1. A unit for use in a wireless telephone system having battery-saving standby modes, said unit comprising:

receiver circuits for receiving transmissions from said telephone system;

means for entering a first low-power sleep-mode during periods of normal expected use by disabling said receiver circuits and awakening from said low-power sleep-mode at regular intervals to receive a signal from said telephone system;

means for entering a second low-power sleep-mode during periods of low expected use from which said telephone awakens less frequently than in said first low-power sleep mode and wherein said means for entering said second sleep-mode includes means for monitoring paging messages sent to other telephones to determine a periodicity of paging message transmission and wherein said means for entering said second sleep-mode enters said second sleep mode at times based upon said periodicity.

2. The unit according to claim 1, wherein said second low-power sleep-mode has a lower power level than said first low-power sleep-mode.

3. The unit according to claim 1, wherein said means for entering said second sleep-mode enters said second sleep-mode when an indication that said second sleep-mode is permitted is transmitted by said system.

4. The unit according to claim 1, wherein said means for entering said second sleep-mode enters said second sleep-mode when a user of said telephone inputs a command to enter said second sleep-mode.

5. A unit according to claim 1 in which said periods of low expected use are determined by a time-of-day clock.

6. A unit according to claim 5 in which said time-of-day clock is included in said telephone.

7. A unit according to claim 5 in which said time-of-day clock is broadcast by said radio communications system.

8. A unit according to claim 1 in which said periods of low expected use are determined by a time since last call.

9. A unit according to claim 8 in which said time since last call is measured using a timer built into said portable telephone.

10. A unit according to claim 1 further comprising:

means to monitor activity by computing a cumulative activity value;

means to increase said cumulative activity value whenever a call is placed or received;

means to gradually decrease said cumulative activity value whenever said phone is not being used for conversation; and

means to place said telephone in said first or second sleep mode based on said cumulative activity value.

11. A method for conserving battery power of a remote unit in a radiocommunication system comprising the steps of:

operatively powering receiver circuitry when said remote unit is actively engaged in a connection with said radiocommunication system;

entering a first low-power sleep-mode after said remote unit has released said connection, and during periods of normal expected use, by disabling said receiver circuits and awakening from said low-power sleep-mode at regular intervals to receive a signal from said telephone system;

entering a second low-power sleep-mode during periods of low expected use from which said telephone awakens less frequently than in said first low-power sleep mode; and

monitoring paging messages sent to other telephones to determine a periodicity of paging message transmission and wherein said means for entering said second sleep-mode enters said second sleep mode at times based upon said periodicity.

12. The method according to claim 11, wherein said second low-power sleep-mode has a lower power level than said first low-power sleep-mode.

13. The method according to claim 11, wherein said step of entering said second sleep-mode further comprises the step of:

entering said second sleep-mode when an indication that said second sleep-mode is permitted is transmitted by said system.

14. The method according to claim 11, wherein said step of entering said second sleep-mode further comprises the step of:

entering said second sleep-mode when a user of said telephone inputs a command to enter said second sleep-mode.

15. A unit for use in a wireless telephone system having battery-saving standby modes, said unit comprising:

receiver circuits for receiving transmissions from said telephone system;

means for entering a first low-power sleep-mode by disabling said receiver circuits and awakening from said low-power sleep-mode at regular intervals to receive a signal from said telephone system;

means for entering a second low-power sleep-mode during which said unit awakens less frequently than in said first low-power sleep mode;

wherein said means for entering said second low-power sleep-mode is commanded by a signal received from said telephone system.

16. A method for conserving battery power of a remote unit in a radiocommunication system comprising the steps of:

operatively powering receiver circuitry when said remote unit is actively engaged in a connection with said radiocommunication system;

entering a first low-power sleep-mode after said remote unit has released said connection by disabling said receiver circuits and awakening from said low-power sleep-mode at regular intervals to receive a signal from said telephone system;

receiving a command from said system to enter a second low-power sleep mode; and

entering, responsive to said command, a second low-power sleep-mode from which said remote unit awakens less frequently than in said first low-power sleep mode.

17. A unit for use in a wireless telephone system having battery-saving standby modes, said unit comprising:

receiver circuits for receiving transmissions from said telephone system;

means for entering a first low-power sleep-mode by disabling said receiver circuits and awakening from said low-power sleep-mode at regular intervals to receive a signal from said telephone system;

means for entering a second low-power sleep-mode during which said unit awakens less frequently than in said first low-power sleep mode;

wherein said means for entering said second low-power sleep-mode includes means for monitoring an accumulated activity level of said unit and entering said second low-power sleep mode based on said accumulated activity level.

18. A method for conserving battery power of a remote unit in a radiocommunication system comprising the steps of:

operatively powering receiver circuitry when said remote unit is actively engaged in a connection with said radiocommunication system;

entering a first low-power sleep-mode after said remote unit has released said connection by disabling said receiver circuits and awakening from said low-power sleep-mode at regular intervals to receive a signal from said telephone system;

accumulating an activity level of said remote unit; and

entering, responsive to said accumulated activity level, a second low-power sleep-mode from which said remote unit awakens less frequently than in said first low-power sleep mode.