US5631958A — Automatic echo cancellation for an integrated ser…

Claim 1

Independent Claim 203 words

A method of processing telecommunications signals, comprising the steps of: detecting a request to establish a call to be conducted on a channel of a communication link having a plurality of channels; determining, from the request, whether the requested call is of a predetermined type requiring a signal processing function to be applied to signals communicated during the call; and applying said signal processing function to signals communicated during said call, when the call is determined to be of the predetermined type; wherein said detecting step comprises the steps of: monitoring transmissions conducted on a first channel of said communication link; identifying, within said first channel, a request message including said request to establish a call upon a second channel of the communication link; obtaining, from said request message, a first call reference value assigned to the requested call, an information content value identifying the type of information contained in said requested call, and a channel identification value identifying said second channel; comparing the information content value with a predetermined information content value for which said signal processing function is to be applied; and storing said call reference value, said channel identification value, and a flag indicating the outcome of said comparing step.

Claim 2

Independent Claim 203 words

A method of processing telecommunications signals, comprising the steps of: detecting a request to establish a call to be conducted on a channel of a communication link having a plurality of channels; determining, from the request, whether the requested call is of a predetermined type requiring a signal processing function to be applied to signals communicated during the call; and applying said signal processing function to signals communicated during said call, when the call is determined to be of the predetermined type; wherein said detecting step comprises the steps of: monitoring transmissions conducted on a first channel of said communication link; identifying, within said first channel, a request message including said request to establish a call upon a second channel of the communication link; obtaining, from said request message, a first call reference value assigned to the requested call, an information content value identifying the type of information contained in said requested call, and a channel identification value identifying said second channel; comparing the information content value with a predetermined information content value for which said signal processing function is to be applied; and storing said call reference value, said channel identification value, and a flag indicating the outcome of said comparing step.

Claim 3

Dependent Claim 89 words

The method of claim 1 wherein said determining step comprises the steps of: identifying, within said first channel, the presence of a call control message identifying an established call; obtaining, from said call control message, a second call reference value; comparing the second call reference value with the first call reference value from the request message; and instructing a signal processor whether to apply said signal processing function to signals within said second channel, on the basis of said flag stored in association with said first call reference value.

Claim 4

Dependent Claim 13 words

The method of claim 2 wherein said signal processing function includes echo cancellation.

Claim 5

Independent Claim 194 words

An apparatus for selectively canceling echo between a local communication network and an integrated services digital network, comprising: a send input for receiving a first multi-channel signal from a local communication network; a receive input for receiving a second multi-channel signal from an integrated services digital network; a receive output, connected with said receive input, for transmitting said second multi-channel signal to the local communication network; an echo canceler, connected with said receive input and with said send input, for removing echo from a channel of the first multi-channel signal, and thereby producing a third multi-channel signal having echo canceled from said channel; a send output for transmitting said third multi-channel signal to the integrated services digital network; and selection means for (i) monitoring a first channel of at least one of said first and second multi-channel signals, (ii) detecting a call control message within said first channel identifying the type of signal within a second channel of said at least one of said first and second multi-channel signals, (iii) determining whether said identified type of signal requires echo cancellation, and (iv) instructing said echo canceler to select said second channel for echo cancellation.

Claim 6

Independent Claim 194 words

An apparatus for selectively canceling echo between a local communication network and an integrated services digital network, comprising: a send input for receiving a first multi-channel signal from a local communication network; a receive input for receiving a second multi-channel signal from an integrated services digital network; a receive output, connected with said receive input, for transmitting said second multi-channel signal to the local communication network; an echo canceler, connected with said receive input and with said send input, for removing echo from a channel of the first multi-channel signal, and thereby producing a third multi-channel signal having echo canceled from said channel; a send output for transmitting said third multi-channel signal to the integrated services digital network; and selection means for (i) monitoring a first channel of at least one of said first and second multi-channel signals, (ii) detecting a call control message within said first channel identifying the type of signal within a second channel of said at least one of said first and second multi-channel signals, (iii) determining whether said identified type of signal requires echo cancellation, and (iv) instructing said echo canceler to select said second channel for echo cancellation.

Claim 7

Dependent Claim 144 words

The apparatus of claim 4 wherein said echo canceler comprises: a plurality of echo canceler modules, each connected for receiving a channel of said first multi-channel signal and removing echo therefrom, whereby a plurality of echo-cancelled signal channels can be provided; and a routing network operatively connected to said selection means for (i) routing an echo-cancelled signal from one of said echo canceler modules into a corresponding channel of the third multi-channel signal, in response to a first configuration control signal from said selection means and (ii) routing a signal within one of the channels of said first multi-channel signal into a corresponding channel of the third multi-channel signal in response to a second configuration control signal from said selection means, whereby echo cancellation in the channels of the first multi-channel signal is selectively provided in the corresponding channels of the third multi-channel signal.

Claim 8

Dependent Claim 228 words

An echo canceling system for an integrated services digital network, comprising a send input terminal for receiving a send input signal having a plurality of B-channels and a D-channel; a send output terminal for transmitting a send output signal having a plurality of B-channels; an activation controller connected with said send input terminal for (i) detecting a D-channel message within said send input signal, (ii) determining whether said detected D-channel message includes a call control message pertaining to a call on a send-input B-channel, and (iii) producing an activation signal indicating whether echo cancellation is required for said call on said send-input B-channel; an echo canceler having an input path for receiving a send-input B-channel signal from said send input terminal, and an output path for providing a send-output B-channel signal from which echo has been canceled relative to said send-input B-channel signal; and a routing network connected with said output path and said send input terminal, said routing network being configured (i) for routing a B-channel signal from said output path to said send output terminal when said activation signal indicates that echo cancellation is required on the corresponding send input B-channel and (ii) for routing a B-channel signal from said send input terminal directly to said send output terminal when said activation signal indicates that echo cancellation is not required on the corresponding send input B-channel.

Claim 9

Dependent Claim 228 words

An echo canceling system for an integrated services digital network, comprising a send input terminal for receiving a send input signal having a plurality of B-channels and a D-channel; a send output terminal for transmitting a send output signal having a plurality of B-channels; an activation controller connected with said send input terminal for (i) detecting a D-channel message within said send input signal, (ii) determining whether said detected D-channel message includes a call control message pertaining to a call on a send-input B-channel, and (iii) producing an activation signal indicating whether echo cancellation is required for said call on said send-input B-channel; an echo canceler having an input path for receiving a send-input B-channel signal from said send input terminal, and an output path for providing a send-output B-channel signal from which echo has been canceled relative to said send-input B-channel signal; and a routing network connected with said output path and said send input terminal, said routing network being configured (i) for routing a B-channel signal from said output path to said send output terminal when said activation signal indicates that echo cancellation is required on the corresponding send input B-channel and (ii) for routing a B-channel signal from said send input terminal directly to said send output terminal when said activation signal indicates that echo cancellation is not required on the corresponding send input B-channel.

Claim 10

Dependent Claim 110 words

The echo canceling system of claim 6, comprising: a receive input terminal for receiving a receive input signal having a plurality of B-channels and a D-channel; and a receive output terminal connected with said receive input terminal for transmitting said receive input signal as a receive output signal; and wherein said activation controller is connected with said receive input terminal for (i) detecting a second D-channel message within said receive input signal, (ii) determining whether said second D-channel message includes a predetermined call control message pertaining to a call on a B-channel, and for producing said activation signal indicating whether echo cancellation is required for said call on said B-channel.

Claim 11

Dependent Claim 25 words

The echo canceling system of claim 6, wherein said call control message includes a message associated with the establishment of a call on said B-channel.

Claim 12

Dependent Claim 24 words

The echo canceling system of claim 8, wherein said call control message is at least one of a SETUP message or CONNECT ACKNOWLEDGE message.

Claim 13

Dependent Claim 83 words

The echo canceling system of claim 8, wherein said activation controller is responsive to a further call control message associated with the termination of a call on said send input B-channel, and wherein said activation controller responds to said further call control message by producing an activation signal indicating that echo cancellation is required on said send input B-channel, whereby echo cancellation is activated by default on said B-channel regardless of any call control message detected prior to said further call control message.

Claim 14

Dependent Claim 188 words

An echo canceling system for use with a telecommunication link in which a multi-channel signal is transmitted, said system comprising: a protocol controller connected to receive a multi-channel signal containing a message frame that includes a plurality of data fields, said protocol controller being formed (i) to monitor a channel of the multi-channel signal, (ii) to detect the message frame in the monitored channel, and (iii) to provide an interrupt signal when the message frame is detected; a processor connected with said protocol controller for receiving the interrupt signal therefrom, and, in response to the interrupt signal, (i) receive the data fields from said protocol controller, (ii) determine whether the data fields contain a call control message pertaining to a call in a second channel of the multi-channel signal, (iii) determine whether the call control signal pertains to a call requiring echo cancellation, and (iv) provide an enable signal when the call control signal pertains to a call requiring echo cancellation; and an echo canceler operatively connected with said processor to receive said enable signal and to apply echo cancellation to the second channel of the multi-channel signal.

Claim 15

Dependent Claim 188 words

An echo canceling system for use with a telecommunication link in which a multi-channel signal is transmitted, said system comprising: a protocol controller connected to receive a multi-channel signal containing a message frame that includes a plurality of data fields, said protocol controller being formed (i) to monitor a channel of the multi-channel signal, (ii) to detect the message frame in the monitored channel, and (iii) to provide an interrupt signal when the message frame is detected; a processor connected with said protocol controller for receiving the interrupt signal therefrom, and, in response to the interrupt signal, (i) receive the data fields from said protocol controller, (ii) determine whether the data fields contain a call control message pertaining to a call in a second channel of the multi-channel signal, (iii) determine whether the call control signal pertains to a call requiring echo cancellation, and (iv) provide an enable signal when the call control signal pertains to a call requiring echo cancellation; and an echo canceler operatively connected with said processor to receive said enable signal and to apply echo cancellation to the second channel of the multi-channel signal.

Claim 16

Dependent Claim 55 words

The echo canceling system of claim 11 wherein said protocol controller comprises: a first protocol controller for detecting message frames transmitted in a first direction of transmission within the telecommunications link; and a second protocol controller for detecting message frames transmitted within the telecommunications link in a direction of transmission opposite to said first direction.

Claim 17

Dependent Claim 126 words

An echo canceling system for an integrated services digital network, comprising a send input terminal for receiving send input signals; a send output terminal for transmitting send output signals; an activation controller connected with said send input terminal for (i) detecting a D-channel message within said send input signals, (ii) determining whether said detected D-channel message includes a call control message pertaining to a call on at least one B-channel within said input signals, and (iii) producing an activation signal indicating whether echo cancellation is required for said call on said at least one B-channel; and an echo canceler operatively connected to receive said activation signal from said activation controller for applying echo cancellation to said at least one B-channel in response to said activation signal.

Claim 18

Dependent Claim 126 words

An echo canceling system for an integrated services digital network, comprising a send input terminal for receiving send input signals; a send output terminal for transmitting send output signals; an activation controller connected with said send input terminal for (i) detecting a D-channel message within said send input signals, (ii) determining whether said detected D-channel message includes a call control message pertaining to a call on at least one B-channel within said input signals, and (iii) producing an activation signal indicating whether echo cancellation is required for said call on said at least one B-channel; and an echo canceler operatively connected to receive said activation signal from said activation controller for applying echo cancellation to said at least one B-channel in response to said activation signal.

Claim 19

Dependent Claim 105 words

The echo canceling system of claim 13, comprising: a receive input terminal for receiving receive input signals; and a receive output terminal connected with said receive input terminal for transmitting said receive input signals as receive output signals; and wherein said activation controller is connected with said receive input terminal for (i) detecting a D-channel message within said receive input signals, (ii) determining whether said detected D-channel message includes a second call control message pertaining to a call on said at least one B-channel, and for producing an activation signal indicating whether echo cancellation is required for said call on said at least one B-channel.

Claim 20

Dependent Claim 28 words

The echo canceling system of claim 14, wherein said call control message includes a message associated with the establishment of a call on said at least one B-channel.

Claim 21

Dependent Claim 25 words

The echo canceling system of claim 15, wherein said call control message is at least one of a SETUP message or a CONNECT ACKNOWLEDGE message.

Claim 22

Dependent Claim 87 words

The echo canceling system of claim 14, wherein said activation controller is responsive to a further call control message associated with the termination of a call on said at least one B-channel, and wherein said activation controller responds to said further call control message by producing an activation signal indicating that echo cancellation is to be enabled on said B-channel, whereby echo cancellation is activated by default on said at least one B-channel regardless of any call control message detected prior to said further call control message.

Claim 23

Independent Claim 92 words

A method of canceling echo within a communication link having a plurality of communication channels, comprising the steps of: detecting a request message to establish a call on a channel of the communication link; determining, on the basis of information encoded within said request message, whether the requested call is of a type requiring echo cancellation to be applied to signals communicated during the call; and applying echo cancellation to signals communicated within said channel during said call when the information encoded in said request message indicates that echo cancellation is required.

Claim 24

Independent Claim 92 words

A method of canceling echo within a communication link having a plurality of communication channels, comprising the steps of: detecting a request message to establish a call on a channel of the communication link; determining, on the basis of information encoded within said request message, whether the requested call is of a type requiring echo cancellation to be applied to signals communicated during the call; and applying echo cancellation to signals communicated within said channel during said call when the information encoded in said request message indicates that echo cancellation is required.

Claim 25

Dependent Claim 34 words

The method of claim 18 wherein said applying step comprises the step of initiating echo cancellation within said channel in response to an acknowledgement message which signifies that the requested call has been established.

Claim 26

Dependent Claim 34 words

The method of claim 18 wherein said applying step comprises the step of disabling echo cancellation within said channel in response to an acknowledgement message which signifies that the requested call has been established.

Claim 27

Dependent Claim 32 words

The method of claim 20, further comprising: detecting a call control message indicating the termination of the call; and re-enabling echo cancellation within said channel in response to said call control message.

Claim 28

Dependent Claim 38 words

The method of claim 18 wherein said detecting step comprises storing said request message in a storage means for storing a plurality of messages, and wherein said determining step comprises retrieving said request message from the storage means.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2000-05-19	2000-11-18	2001-05-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2004-05-19	2004-11-18	2005-05-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2008-05-19	2008-11-18	2009-05-20	$7700.00	Window Closed / Lapsed

Automatic echo cancellation for an integrated services digital network interface

Abstract

Inventors

Bibliographic Details

Claims Analysis

References Cited (Backward Citations)

USPTO Annuity & Maintenance Windows

Assigned Categories & Tags

Assign Category Tag