Digital voice conferencing bridge

• US 4,937,856 A
• Filed: 06/01/1987
• Issued: 06/26/1990
• Est. Priority Date: 06/01/1987
• Status: Expired due to Term

• Current Assignee: DSPC Technologies Limited
• Original Assignee: DSPC Technologies Limited
• Inventors: Natarajan, T. Raj
• Primary Examiner(s): Ng, Jin F.
• Assistant Examiner(s): Chan, Wing F.
• Application Number:
  US07/057,091
• Time in Patent Office: 1,121 Days
• Field of Search: 379/158, 379/202, 379/203, 379/204, 379/205, 379/158, 379/202-206, 370/62
• US Class Current: 379/158
• CPC Class Codes: H04M 3/561 by multiplexing
• CPC Class Codes: H04M 3/568 audio processing specific to telephonic conferencing, e.g. spatial distribution, mixing of participants echo suppression in two-way loud-speaking telephone systems H04M9/02; sound field processing per se H04S7/30
• CPC Class Codes: H04M 3/569 using the instant speaker's algorithm speech detection per se G10L25/78

Abstract

A conferencing bridge provides conferencing capabilities for a plurality of input lines and for a plurality of output lines. The conferencing bridge has a signal processor which processes the audio information transferred between the input lines and the output lines. A plurality of codecs analog to digital conversion and digital to analog conversion for interfacing the signal processor to the plurality of input lines and output lines. A control processor is operatively connected to the signal processor and controls and operation of the signal processor as well as the conferencing bridge through number codes that are inputted to the conference bridge via the telephone key pad. A tone converter converts the inputted tones to digital information to which the control processor will respond. The signal processor provides not only identification of the telephone line on which a speaker is talking but also performs an amplitude adjustment so that there is a minimum loss involved for the conferencing network.

Claims

1. A digital voice conferencing bridge comprising:

a first plurality of telephone line terminals;

a second plurality of telephone line terminals;

a first plurality of dual position relay contacts with each single contact being connected to a single telephone line terminal of the first plurality of telephone line terminals;

a second plurality of dual position relay contacts with each single relay contact being connected to a single telephone line terminal of the second plurality of telephone line terminals, each single member of the first plurality of the dual position relay contact being connected to a single member of the second plurality of relay contacts when the first and second plurality of relay contacts are in a first position;

a signal processor including a means for detecting a loudest telephone line based on the mean squared value of the audio energy on the telephone line;

a plurality of codecs connected between the first plurality of dual position relay contacts and the signal processor whereby each single telephone line terminal of the first plurality is connected to a single codec via a predetermined relay contact of the first plurality of relays contacts when the predetermined relay contact is in a second position of the dual positions;

a control processor operatively connected to the signal processor; and

an internal circuit connected between the signal processor and a preselected telephone line terminal of the second plurality of telephone line terminals via a preselected relay contact of the second plurality of relay contacts when the preselected contact is in a second position of the dual position.

2. The digital voice conferencing bridge according to claim 1 further comprising:

a tone converter operatively connected between the control processor and each single telephone line terminal of the predetermined member of the first plurality of relay contacts.

3. The digital voice conferencing bridge according to claim 1 further comprising:

a plurality of ring detectors operatively connected such (as) that each single telephone line terminal of the first plurality of telephone line terminals has a ring detector connected thereto, the plurality of ring detectors being operatively connected to the control processor.

4. The digital voice conferencing bridge according to claim 1 further comprising:

a dial tone detector operatively connected to detect dial tones on each of the first plurality of telephone line terminals.

5. The conferencing bridge according to claim 4 the dial tone detector further includes:

a multiplexer operatively connected between each single telephone line terminal of the first plurality of telephone line terminals and the dial tone detector.

6. A digital voice conferencing bridge comprising:

a first means for connecting a first plurality of telephone lines to the digital voice conferencing bridge;

a second means for connecting the digital voice conferencing bridge to a second plurality of telephone lines;

a signal processor means for processing signals applied thereto and includes a means for detecting a loudest telephone line based on the mean squared value of the audio energy on the telephone line;

a plurality of codec means for converting analog signals to digital signals when applied to a first input and for converting the digital signals to analog signals when applied to a second input, said plurality of codec means being operatively connected to signal processor means;

switch means for selectively switching predetermined members of the first and second means to preselected members of the plurality of codec means; and

a control processor means for controlling the operation of the switch means and signal processor means.

7. The digital voice conferencing bridge according to claim 6 further comprising:

a tone converter means operatively connected between the control processor means and the first and second means for converting tones applied thereto to digital data.

8. The digital voice conferencing bridge according to claim 6 further comprising:

ring detector means for detecting a telephone ring, the ring detector means being operatively connected to the first means and to pass an indication of a detected ring to the control processor means.

9. The digital voice conferencing bridge according to claim 6 further comprising:

means for adjusting the signal gain of each signal applied to the signal processor means.

10. A method of voice conferencing comprising:

connecting a first plurality of telephone lines to a digital voice conferencing bridge with a first means;

connecting the digital voice conferencing bridge to a second plurality of telephone lines with a second means;

processing signals applied with a signal processor means, including the step of adjusting the signal gain of each signal applied to the signal processor means;

converting analog signals to digital signals with a plurality of codec means when applied to a first input and for converting digital signals to analog signals when applied to a second input, said plurality of codec means being operatively connected to the signal processor means;

selectively switching predetermined members of the first and second means to preselected members of the plurality of codec means with a switch means; and

controlling the operation of the switch means and signal processor means with a control processor means.

11. The method according to claim 10 further comprising:

converting tones applied to preselected members of the first and second plurality of telephone lines to digital data.

12. The method according to claim 10 further comprising:

detecting a telephone ring with a ring detector means operatively connected to the first and second plurality of telephone lines and passing an indicator of a detected ring to the control processor means.

13. The method according to claim 10 further comprising the step of:

detecting a loudest telephone line based on the mean squared value of the audio energy on the telephone line.