Imminent change warning

• US 5,722,068 A
• Filed: 01/26/1994
• Issued: 02/24/1998
• Est. Priority Date: 01/26/1994
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: OKI Telecom, Inc. (OKI Electric Industry Company Limited)
• Inventors: Bartle, Alden S., Erickson, George D.
• Primary Examiner(s): Coles, Sr., Edward L.
• Assistant Examiner(s): Williams, Kimberly A.
• Application Number:
  US08/186,777
• Time in Patent Office: 1,490 Days
• Field of Search: 379/58, 379/59, 379/60, 379/63, 455/33.1, 455/33.2, 455/54.1, 455/421, 455/422, 455/436, 455/438, 455/524, 371/2.1, 371/5.1
• US Class Current: 455/421
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 36/14 Reselecting a network or an air interface
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 76/30 Connection release
• CPC Class Codes: H04W 84/042 Public Land Mobile systems, e.g. cellular systems
• CPC Class Codes: H04W 88/02 Terminal devices

Abstract

A cellular telephone, in its most preferred embodiment, performs a method for notifying a digital cellular telephone user of an imminent communication disconnection. The preferred method includes, at least, generating at least one condition indication representative of at least one communication condition, analyzing the condition indication, determining whether a communication disconnection is imminent, enhancing quality of received communication signals when possible, and notifying the user of an imminent communication disconnection. Exemplary condition indications include, at least, continuous count and rate indications of frame checksum errors, insufficient quality frames, symbol errors, and chip errors, output power level indication, received signal strength indication, soft handoff status indication, other pilot signal indication, and current pilot signal strength indication. One exemplary analysis technique of determining when a communication disconnection is imminent includes evaluating whether any of a set of condition indications violates a predefined threshold indication, while other exemplary analysis techniques include evaluating whether fixed or historically adaptive combinations of condition indications violate run predefined thresholds, and evaluating combinations of condition indications weighted according to the degree of threshold violation. The process further uses a memory flag in a delayed redundant comparison before enabling a warning, examples of which include visual, sensory, and audible notification methods, including adding generated noise to the received audio signal. Alternate methods of the invention include notifying a user of an imminent inter-system handoff or an imminent change in communication mode.

Claims

1. A method of notifying a user of a code division multiple access digital cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating, at the code division multiple access digital cellular telephone, a condition indication representative of a communication condition;

analyzing the condition indication to determine at the code division multiple access digital cellular telephone whether a communication disconnection is imminent;

enhancing received communication signal quality, responsive to determining the communication disconnection is imminent, wherein the enhancing step includes a step of operating additional demodulator fingers to enhance received communication quality; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

2. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating, at the cellular telephone, a condition indication representative of a communication condition, wherein the generating a condition indication step includes steps of

evaluating current frame validity, including steps of

calculating a current frame checksum, and

comparing the calculated frame checksum to a predefined frame checksum,

generating a frame checksum error responsive to the calculated frame checksum differing from the predefined frame checksum, and

generating a count of continuous frame checksum errors indication;

analyzing the condition indication to determine at the cellular telephone whether a communication disconnection is imminent;

continually repeating the generating and analyzing steps during a telephone call; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

3. The method of claim 2, wherein the generating a condition indication step further includes a step of

generating a rate of frame checksum errors indication.

4. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating, at the cellular telephone, a condition indication representative of a communication condition, wherein the generating a condition indication step includes steps of

evaluating current frame quality to determine whether the current frame is of insufficient quality,

generating a current insufficient quality frame error responsive to determining the current frame is of insufficient quality, and

generating a count of continuous insufficient quality frame errors indication;

analyzing the condition indication to determine at the cellular telephone whether a communication disconnection is imminent;

continually repeating the generating and analyzing steps during a telephone call; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

5. The method of claim 4, wherein the generating a condition indication step further includes a step of generating a rate of insufficient quality frame errors indication.

6. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating, at the cellular telephone, a condition indication representative of a communication condition, wherein the generating a condition indication step includes steps of

evaluating current symbol quality to determine whether the current symbol is of insufficient quality,

generating a current insufficient quality symbol error responsive to determining the current symbol is of insufficient quality, and

generating a count of continuous insufficient quality symbol errors indication;

analyzing the condition indication to determine at the cellular telephone whether a communication disconnection is imminent;

continually repeating the generating and analyzing steps during a telephone call; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

7. The method of claim 6, wherein the generating a condition indication step further includes a step of generating a rate of insufficient quality symbol errors indication.

8. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating, at the cellular telephone, a condition indication representative of a communication condition, wherein the generating a condition indication step includes steps of

evaluating current chip quality to determine whether the current chip is of insufficient quality,

generating a current insufficient quality chip error responsive to determining the current chip is of insufficient quality, and

generating a count of continuous insufficient quality chip errors indication;

analyzing the condition indication to determine at the cellular telephone whether a communication disconnection is imminent;

continually repeating the generating and analyzing steps during a telephone call; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

9. The method of claim 8, wherein the generating a condition indication step further includes a step of generating a rate of insufficient quality chip errors indication.

10. A method of notifying a user of a code division multiple access digital cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating, at the code division multiple access digital cellular telephone, a condition indication representative of a communication condition;

analyzing the condition indication to determine at the code division multiple access digital cellular telephone whether a communication disconnection is imminent;

enhancing received communication signal quality, responsive to determining the communication disconnection is imminent, wherein the enhancing step includes a step of operating additional echo cancellers to cancel additional inter-symbol interference; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

11. A method of notifying a user of a code division multiple access digital cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating, at the code division multiple access digital cellular telephone, a condition indication representative of a communication condition;

analyzing the condition indication to determine at the code division multiple access digital cellular telephone whether a communication disconnection is imminent;

enhancing received communication signal quality, responsive to determining the communication disconnection is imminent, wherein the enhancing step includes a step of substituting previous frames for current frames; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

12. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising the steps of:

generating a first condition indication at the cellular telephone representative of a communication condition during a first period;

comparing, at the cellular telephone, the first condition indication to a predefined condition threshold;

setting a flag memory element at the cellular telephone responsive to the step of comparing the first condition indication;

generating a second condition indication at the cellular telephone representative of the communication condition during a second period;

comparing, at the cellular telephone, the second condition indication to the predefined condition threshold;

analyzing, at the cellular telephone, the flag memory element and the comparing of the second condition to determine whether a communication disconnection is imminent; and

notifying the user that a communication disconnection is imminent responsive to determining a communication disconnection is imminent.

13. The method of claim 12, further comprising a step of delaying for a predefined amount of time after the setting step before the step of generating a second condition indication.

14. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating, at the cellular telephone, a condition indication representative of a communication condition;

analyzing the condition indication to determine at the cellular telephone whether a communication disconnection is imminent; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent, wherein the notifying step includes steps of

generating an audible noise sound including a step of generating random data words with a random pattern generator, and

adding the noise to received audio signals including a step of summing the random data words with received digitized audio data.

15. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating a first condition indication at the cellular telephone representative of a first communication condition;

generating a second condition indication at the cellular telephone representative of a second communication condition, wherein the first communication condition and the second communication condition are distinct and different types of communication conditions;

analyzing, at the cellular telephone, both the first condition indication and the second condition indication to determine whether a communication disconnection is imminent, wherein the analyzing step includes a step of evaluating each condition indication as a weighted factor in determining whether the communication disconnection is imminent; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

16. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating a first condition indication at the cellular telephone representative of a first communication condition;

generating a second condition indication at the cellular telephone representative of a second communication condition, wherein the first communication condition and the second communication condition are distinct and different types of in progress call communication quality conditions;

analyzing, at the cellular telephone, both the first condition indication and the second condition indication to determine whether a communication disconnection is imminent, wherein the analyzing step includes steps of

comparing the first condition indication to a predefined first condition threshold,

comparing the second condition indication to a predefined second condition threshold, and

determining that the communication disconnection is imminent if either predefined condition threshold is violated; and

notifying the user through a common notification that the communication disconnection is imminent responsive to determining the communication disconnection is imminent based upon any communication condition indication.

17. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating a cellular handoff status indication at the cellular telephone representative of a cellular handoff status;

generating a current pilot signal strength indication at the cellular telephone representative of a current pilot signal strength, wherein the cellular handoff status and the current pilot signal strength are distinct and different types of communication conditions;

analyzing, at the cellular telephone, both the cellular handoff status indication and the current pilot signal strength indication to determine whether a communication disconnection is imminent, wherein the analyzing step includes determining that the communication disconnection is imminent when both the current pilot signal strength is below a predefined threshold and the cellular telephone is not experiencing a soft handoff; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

18. A method of notifying a user of a cellular telephone during cellular communication of an imminent communication disconnection, said method comprising steps of:

generating an other pilot signal detection indication at the cellular telephone representative of whether a pilot signal other than a current pilot signal is detectable;

generating a current pilot signal strength indication at the cellular telephone representative of a current pilot signal strength, wherein whether the pilot signal other than the current pilot signal is detectable and the current pilot signal strength are distinct and different types of communication conditions;

analyzing, at the cellular telephone, both the other pilot signal detection indication and the current pilot signal strength indication to determine whether a communication disconnection is imminent, wherein the analyzing step includes determining that the communication disconnection is imminent when both the current pilot signal strength is below a predefined threshold and only the current pilot signal is detected; and

notifying the user that the communication disconnection is imminent responsive to determining the communication disconnection is imminent.

19. A method of notifying a cellular telephone user during cellular communication of an imminent communication disconnection, said method comprising the steps of:

generating a first plurality of condition indications representative of a first plurality of communication conditions, including the steps of

generating a count of continuous frame checksum errors indication,

generating a rate of frame checksum errors indication,

generating a count of continuous insufficient quality frames indication,

generating a rate of insufficient quality frames indication,

generating a count of continuous symbol errors indication,

generating a rate of symbol errors indication,

generating a count of continuous chip errors indication,

generating a rate of chip errors indication,

generating a transmitter output power level indication, and

generating a received signal strength indication;

analyzing the first plurality of condition indications to determine that a communication disconnection is imminent if any one of indications violates a predefined indication threshold;

generating a second plurality of condition indications representative of a second plurality of communication conditions, including the steps of

generating a soft handoff indication, generating an other pilot signal detection indication, and

generating a current pilot signal strength indication;

analyzing the second plurality of condition indications to determine that a communication disconnection is imminent if both the current pilot signal strength indication is below a predefined threshold and neither a soft handoff indication nor an other pilot signal detection indication is generated; and

audibly and visually notifying the user that a communication disconnection is imminent responsive to determining a communication disconnection is imminent.