Method of making conference call connections in computer-controlled digital telephone exchanges

• US 4,809,262 A
• Filed: 02/22/1988
• Issued: 02/28/1989
• Est. Priority Date: 02/23/1987
• Status: Expired due to Fees

• Current Assignee: Deutsche Telephonwerke und Kabelindustrie AG
• Original Assignee: Deutsche Telephonwerke und Kabelindustrie AG
• Inventors: Klose, Reinhard, Schroter, Jurgen
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Scutch, Frank
• Application Number:
  US07/158,574
• Time in Patent Office: 372 Days
• Field of Search: 370/62, 370/110.1, 370/58, 370/109, 379/202, 379/206
• US Class Current: 370/268
• CPC Class Codes: H04M 3/561 by multiplexing
• CPC Class Codes: H04M 3/569 using the instant speaker's algorithm speech detection per se G10L25/78

Abstract

A method of making conference call connections in computer-controlled telephone exchanges includes combining voice signals of conference participants on a digital basis, forming a signal of a total of speaking levels of a given number of the most active participants, distributing the signal in an undamped manner, and suppressing voice signals of the inactive participants. A bit stream of the conference participants reaching a conference assembly through an incoming line is distributed to m adding processors having n channels each, and the PCM words are linearized with a code table and stored in level memories for each particular participant. A total of the linear values is formed, is added to individual participant evaluation totals and is stored in evaluation memories for each particular participant. The participant evaluation totals are transmitted to an evaluation processor which determines active channels by using a delayed mean value of the participant levels and transmits it to the adding processors. A conference total signal is created by adding linear values of all channels. Transmission signals for all channels are formed in the adding processors by compressing the conference total signal, the individual linear value of the active participants being substracted before compression. The signals thus created are stored in transmitting memories and transmitted through an outgoing line.

Claims

1. In a method of making conference call connections in computer-controlled telephone exchanges, which includes combining voice signals of conference participants on a digital basis, forming a signal of a total of speaking levels of a given number of the most active participants, distributing the signal in an undamped manner, and suppressing voice signals of the inactive participants, the improvement which comprises:

distributing a bit stream of the conference participants reaching a conference assembly through an incoming line to m adding processors having n channels each, linearizing PCM words by means of a code table, storing the PCM words in level memories for each particular participant;

forming a total of the linear values, adding the total of the linear values to individual participant evaluation totals, and storing the total of the linear values in evaluation memories for each particular participant;

transmitting the participant evaluation totals to an evaluation processor which determines active channels by using a delayed average value of the participant levels and which transmits the active channels to the adding processors;

creating a conference total signal by adding linear values of all channels;

subtracting the individual linear value of the active participants, subsequently forming transmission signals for all channels in the adding processors by compressing the conference total signal;

storing the signals thus created in transmitting memories, and transmitting the signals through an outgoing line.

2. Method according to claim 1, which comprises forming the participant evaluation total by the integration of n linearized PCM words of an adding processor.

3. Method according to claim 2, which comprises reducing the integrated participant evaluation total to 1/n after exactly n PCM frames, and adding the integrated participant evaluation total to an integrated participant level reduced to (n-1)/n, for the formation of a delayed average value.

4. Method according to claim 1, which comprises immediately switching a channel from an inactive state to an active state, and switching a channel from the active state into the inactive state with a delay.

5. Method according to claim 2, which comprises immediately switching a channel from an inactive state to an active state, and switching a channel from the active state into the inactive state with a delay.

6. Method according to claim 3, which comprises immediately switching a channel from an inactive state to an active state, and switching a channel from the active state into the inactive state with a delay.

7. Method according to claim 1, which comprises keeping the channel which was last switched-on in the active state, during the inactive state of all channels.

8. Method according to claim 2, which comprises keeping the channel which was last switched-on in the active state, during the inactive state of all channels.

9. Method according to claim 3, which comprises keeping the channel which was last switched-on in the active state, during the inactive state of all channels.

10. Method according to claim 4, which comprises keeping the channel which was last switched-on in the active state, during the inactive state of all channels.