Method and means for digital conferencing

• US 4,267,593 A
• Filed: 06/15/1979
• Issued: 05/12/1981
• Est. Priority Date: 06/15/1979
• Status: Expired due to Term

• Current Assignee: Wescom Switching Incorporated
• Original Assignee: Wescom Switching Incorporated
• Inventors: Regan, John F., Mehta, Bakulesh A.
• Primary Examiner(s): BROWN, THOMAS
• Application Number:
  US06/048,830
• Time in Patent Office: 697 Days
• Field of Search: 179/18 BC, 179/1 CN, 370/62
• US Class Current: 370/261
• CPC Class Codes: H04M 3/569 using the instant speaker's algorithm speech detection per se G10L25/78

Abstract

A digital conferencing arrangement for use in a digital telecommunications switching system. Digital coded signals representative of sampled analog signals are compared and the results of the comparison noted to identify the present speaker in the conference. A comparison result indicating a proposed new speaker initiates a delay interval during which subsequent samples are compared to assure that the proposed new speaker indeed has the largest analog signal during the delay window. Upon verification of the proposed new speaker, the control of the conference circuit is transferred to him.

Claims

1. In a conference circuit for a digital telecommunications switching system having a comparator for comparing digital samples of conferees and producing an output signal identifying the largest sample, and means for identifying a present speaker and outputting his sample to the conferees during each frame, the improvement comprising, delay means for initiating a delay following detection of a proposed new speaker by said comparator having a sample larger than that of the present speaker, logic means responsive to the comparator and operative during the delay for determining if the proposed new speaker has the largest analog signal during the delay, and means responsive to a positive determination by said logic means and operative upon the identifying means for updating the identity of the present speaker to that of the proposed new speaker.

2. In a conference circuit for a digital telecommunications switching system having comparison means for comparing digital samples of conferees and producing an output signal identifying the largest sample, and means for identifying a present speaker and outputting his sample to the conferees during each frame, the improvement comprising, delay means for initiating a delay following detection of a proposed new speaker by said comparison means having a sample larger than that of the present speaker, monitoring means for monitoring the comparison results during the delay to determine if the proposed new speaker or the present speaker has the largest overall signal, and means for updating the identity of the present speaker to that of the proposed new speaker if the monitoring means determines the proposed new speaker has the largest overall signal during the delay.

3. The improvement as set forth in claim 2 wherein the delay means comprises identity comparison means for comparing the identities of the proposed new speaker and the present speaker, means responsive to the identity comparison means for initiating said delay when said identities are different, means operative upon the completion of said delay for initiating said updating means, and means responsive to the identity comparison means for resetting said delay upon a determination that the identities of the present speaker and the proposed new speaker are the same.

4. The improvement as set forth in claim 2 wherein said delay means includes means for setting the delay at about 3 milliseconds.

5. In a conference circuit for a digital telecommunications switching system having comparison means for comparing digital samples of conferees and producing an output signal identifying the largest sample in a frame, and means for identifying a present speaker and outputting his sample to the conferees during each frame, the improvement comprising, means for identifying a proposed new speaker having the largest sample during a frame, identity comparison means for comparing the identities of the present speaker and the proposed new speaker, means responsive to the identity comparison means for activating a delay means when said identities are different to initiate a delay, means responsive to the delay means for updating the identity of the present speaker to that of the proposed new speaker at the end of said delay, and means responsive to the identity comparison means for prematurely terminating said delay when said identity comparison means indicates that identities are the same, thereby to prevent updating of the present speaker.

6. In a pulse code modulated communication system having a plurality of communication channels, a switching network for switching signals from said channels, and a conference circuit connected to said switching network, said conference circuit comprising comparator means for comparing pulse code modulated samples of conferees and producing as a comparison result an output signal identifying the conferee with the largest sample, means for identifying a present speaker and outputting his sample to the conferees during each frame, the improvement comprising circuit means for opening a decision window following detection of a proposed new speaker having a sample larger than that of the present speaker, logic means operative during the decision window for monitoring the comparison results during said window to determine whether the proposed new speaker or the present speaker has the largest signal during said window, and means for updating the identity of the present speaker to that of the proposed new speaker if the logic means determines the proposed new speaker has the largest signal during the delay window.

7. A method of conferencing in a digital switching system of the type which switches digital samples representing sampled analog signals, the method comprising the steps of, outputting the digital sample of the present speaker to conferees during each frame, comparing the digital samples of the conferees to determine the largest sample in a frame, opening a decision window following detection of a proposed new speaker having a digital sample larger than that of the present speaker, monitoring the results of the comparison during the decision window to determine if the proposed new speaker or the present speaker has the largest overall signal during the decision window, and updating the identity of the present speaker to that of the proposed new speaker if the determination indicates the proposed new speaker has the largest overall signal during the decision window.

8. A method of conferencing in a digital switching system of the type which switches digital samples representing sampled analog signals, the method comprising the steps of outputting the sample of the present speaker to conferees during each frame, comparing the digital samples of the conferees to determine the largest sample in a frame, opening a decision window following detection of a proposed new speaker having a digital sample greater than that of the present speaker, determining if the signal of the proposed new speaker is greater than that of the present speaker during the decision window, and updating the identity of the present speaker to that of the proposed new speaker if said determination is positive.