Adaptive speakerphone system

• US 5,333,171 A
• Filed: 02/09/1993
• Issued: 07/26/1994
• Est. Priority Date: 06/28/1991
• Status: Expired due to Term

• Current Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Original Assignee: Lifeline Systems Company (Koninklijke Philips N.V.)
• Inventors: Wang, William, Reich, Richard M.
• Primary Examiner(s): Kuntz, Curtis
• Assistant Examiner(s): Chan, Jason
• Application Number:
  US08/015,619
• Time in Patent Office: 532 Days
• Field of Search: 379/37, 379/38, 379/39, 379/40, 379/388, 379/389, 379/390, 381/104, 381/107, 381/108, 340/565, 455/68, 455/38.3, 455/127, 455/343, 455/69, 455/34.1, 371/32, 371/33
• US Class Current: 379/37
• CPC Class Codes: H04M 11/04 with alarm systems, e.g. fire, police or burglar alarm systems

Abstract

A system and method for adjusting telephonic control signals transmitted from a central station to a remote station. The signals are automatically adjusted according to the response of the remote station. The signals are adjusted to control speakerphone operation at the remote station in such a way as to provide communication with minimum audible annoyance. The method is especially useful in a personal emergency response system in which the speakerphone is part of a subscriber station to achieve a greater voice range than a voice activated speakerphone system.

Claims

1. A method of operating a communications system including a central station and a remote station, said method comprising the steps of:

a. sending a request signal from the remote station to the central station;

b. receiving at the central station the request signal sent from said remote station;

c. sending a control signal in response to said request signal to said remote station from said central station, said control signal having a signal strength and a signal duration, said control signal for determining signal strength and duration characteristics capable of evoking an acknowledge signal from said remote station and permitting subsequent voice communication;

d. starting a central timer to measure a predetermined amount of time subsequent to sending said control signal;

e. determining if said acknowledge signal has been received from said remote station prior to said central timer measuring said predetermined amount of time;

f. sending a next control signal to said remote station from said central station if said determining step indicates that said acknowledge signal has not been received from said remote station, said next control signal having at least one of;

a signal strength greater than said signal strength of said control signal sent immediately previous to said next control signal; and

a signal duration greater than said signal duration of said control signal sent immediately previous to said next control signal;

g. repeating steps d through f until a first one of;

said remote station responds with said acknowledge signal; and

said steps d through f have been repeated a predetermined number of times; and

h. if said remote station responds with said acknowledge signal, sending at least one subsequent control signal to said remote station from said central station said at least one subsequent control signal having a signal strength and duration equal to the signal strength and duration of the control signal sent by said central station to which said remote station responded.

2. The method of claim 1 further including the step of measuring the strength of the request signal received from said remote station by said central station prior to sending said control signal to said remote station.

3. The method recited in claim 1 wherein said signal strength and duration characteristics are related to signal attenuation during transmission between said remote station and said central station.

4. A system comprising:

a central station; and

a remote station for communicating with said central station wherein said remote station initiates communication with said central station by sending a request signal to said central station and wherein, in response to said request signal, said central station sends a control signal to said remote station, said control signal having a control signal strength and a control signal duration, said control signal for determining signal strength and duration characteristics capable of evoking an acknowledge signal from said remote station and permitting subsequent voice communication;

wherein said central station comprises;

a central timer for measuring a predetermined amount of time following the sending of said control signal; and

a processor for determining if said acknowledge signal has been received from said remote station prior to said central timer measuring said predetermined amount of time, and wherein if said acknowledge signal has not been received from said remote station, said central station sends a next control signal to said remote station, said next control signal having at least one of;

a signal strength greater than said signal strength of said control signal sent immediately previous to said next control signal; and

a signal duration longer than said signal duration of said control signal sent immediately previous to said next control signal; and

wherein said central station sends subsequent control signals with a signal strength and signal duration equal to the signal strength and signal duration of the control signal to which said remote station responded.

5. The system of claim 4 further comprising a signal processing circuit for measuring the signal strength of the request signal received from said remote station.

6. The system recited in claim 4 wherein said signal strength and duration characteristics are related to signal attenuation during transmission between said remote station and said central station.

7. A central station for communicating with a speakerphone at a remote station, said central station comprising:

a central timer for measuring a predetermined amount of time; and

a processor for determining if an acknowledge signal has been received from said remote station prior to said central timer measuring said predetermined amount of time wherein said central station sends a control signal to said remote station in response to a request signal sent to said central station by said remote station, said control signal having a control signal strength and a control signal duration, said control signal for determining signal strength and duration characteristics capable of evoking said acknowledge signal from said remote station and permitting subsequent voice communication, wherein if said central station fails to receive the acknowledge signal from said remote station, said central station sends a subsequent control signal to said remote station said subsequent control signal having at least one of;

a control signal strength greater than the control signal strength of said control signal; and

a control signal duration longer than the control signal duration of said control signal; and

sending additional subsequent control signals at a control signal strength and a control signal duration equal to the control signal strength and the control signal duration of the control signal to which said remote station responded.

8. The central station recited in claim 7 wherein said signal strength and duration characteristics are related to signal attenuation during transmission between said remote station and said central station.