US4797876A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conferencing bridge
Assignee: BCS TECHNOLOGIES Inc A DELAWARE Corp
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Filing: 1987-07-10
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Granted: 1989-01-10
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Expires: 2007-07-10
Abstract
Abstract A conferencing bridge is provided for an electronic telephone system to support telephone conversations involving three or more parties. The conferencing bridge implements a conferencing algorithm using simple arithmetic operations. The conferencing bridge circuitry implements the algorithm by summing each party's contribution to the conference deriving a grand total, and subtracting each party's contribution from the grand total.
Inventors
- 👤 Reginald Ratcliff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:07
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/42; H04M3/56; H04M3/561; H04M3/568
Claims Analysis
Total Claims: 39
Claim 1
Independent Claim
157 words
A conferencing bridge for supporting a telephone conversation involving more than two parties wherein each party transmits a unique PCM bit stream and receives a unique PCM bit stream; comprising: means for receiving first and second incoming serial PCM highways carrying said transmit and receive PCM bit streams; means for converting serial data on said PCM highways to parallel data; arithmetic logic means for implementing a conferencing algorithm and producing a sequence of PCM outputs; means for providing valid output PCM data when an arithmetic overflow occurs without passing said arithmetic logic unit output through a PROM so that propagation delay is minimized; means for providing valid output PCM data when a sum is being cleared without passing said arithmetic logic unit output through a PROM so that propagation delay is minimized; and means for receiving the PCM outputs from said arithmetic logic means, separating said outputs by highway, and converting said outputs to serial data streams.
Claim 2
Dependent Claim
157 words
A conferencing bridge for supporting a telephone conversation involving more than two parties wherein each party transmits a unique PCM bit stream and receives a unique PCM bit stream; comprising: means for receiving first and second incoming serial PCM highways carrying said transmit and receive PCM bit streams; means for converting serial data on said PCM highways to parallel data; arithmetic logic means for implementing a conferencing algorithm and producing a sequence of PCM outputs; means for providing valid output PCM data when an arithmetic overflow occurs without passing said arithmetic logic unit output through a PROM so that propagation delay is minimized; means for providing valid output PCM data when a sum is being cleared without passing said arithmetic logic unit output through a PROM so that propagation delay is minimized; and means for receiving the PCM outputs from said arithmetic logic means, separating said outputs by highway, and converting said outputs to serial data streams.
Claim 3
Dependent Claim
31 words
A conferencing bridge according to claim 1 wherein said algorithm comprises: phase inverting alternate parties; converting the data to fourteen bit two's-complement data; and summing the data creating a grand total.
Claim 4
Dependent Claim
25 words
A conferencing bridge according to claim 2 wherein said algorithm further comprises attenuating said fourteen bit two's-complement data by about three decibels whenever so commanded.
Claim 5
Dependent Claim
29 words
A conferencing bridge according to claim 2 wherein said algorithm further comprises generating a return signal for each party by subtracting each party's own contribution from said grand total.
Claim 6
Dependent Claim
38 words
A conferencing bridge according to claim 2 wherein said means for providing valid output PCM data when an arithmetic overflow occurs includes a logic gate substituting a zero or a predetermined value in response to an overflow condition.
Claim 7
Dependent Claim
40 words
A conferencing bridge according to claim 1 wherein said means for providing valid PCM output data when a sum is being cleared includes a logic gate substituting a zero or a predetermined value in response to a sum being cleared.
Claim 8
Dependent Claim
22 words
A conferencing bridge according to claim 6 further comprising means for selectively attenuating said fourteen bit two's-complement data by about three decibels.
Claim 9
Dependent Claim
28 words
A conferencing bridge according to claim 6 further comprising means for generating a return signal for each party by subtracting each party's own contribution from said grand total.
Claim 10
Dependent Claim
20 words
A conferencing bridge according to claim 1 wherein said conferencing bridge can accommodate up to sixty-four parties in a conference.
Claim 11
Dependent Claim
128 words
A conferencing bridge for supporting a telephone conversation involving more than two parties wherein each party transmits a stream of unique PCM data bits and receives a stream of unique PCM data bits; comprising: input means for receiving first and second incoming serial PCM highways carrying said transmit and receive PCM data and converting data on said PCM highways to parallel data; means for temporarily storing samples of said parallel data; means for storing a command byte associated with each of the parties to the conversation; arithmetic logic means for implementing a conferencing algorithm by performing sample summations and subtractions and producing PCM outputs; means for receiving the PCM outputs from said arithmetic logic means, separating said outputs by highway, and converting said outputs to serial data streams.
Claim 12
Dependent Claim
128 words
A conferencing bridge for supporting a telephone conversation involving more than two parties wherein each party transmits a stream of unique PCM data bits and receives a stream of unique PCM data bits; comprising: input means for receiving first and second incoming serial PCM highways carrying said transmit and receive PCM data and converting data on said PCM highways to parallel data; means for temporarily storing samples of said parallel data; means for storing a command byte associated with each of the parties to the conversation; arithmetic logic means for implementing a conferencing algorithm by performing sample summations and subtractions and producing PCM outputs; means for receiving the PCM outputs from said arithmetic logic means, separating said outputs by highway, and converting said outputs to serial data streams.
Claim 13
Dependent Claim
23 words
A conferencing bridge according to claim 10 further comprising logic gate means for providing valid output PCM data when an arithmetic overflow occurs.
Claim 14
Dependent Claim
24 words
A conferencing bridge according to claim 10 further comprising logic gate means for providing valid output PCM data when a sum is being cleared.
Claim 15
Dependent Claim
67 words
A conferencing bridge according to claim 10 wherein said input and output PCM data are in standard μ law companded format which is a piecewise linear approximation to a logarithmic curve and wherein said arithmetic logic means includes means for converting said input data to an equivalent linear format prior to performing sample summations and subtractions and afterwards transforming the data back to μ law companded format.
Claim 16
Dependent Claim
16 words
A conferencing bridge according to claim 13 wherein the equivalent linear format is signed two's complement.
Claim 17
Dependent Claim
20 words
A conferencing bridge according to claim 10 further comprising means for scaling contributions of each party to the input data.
Claim 18
Dependent Claim
24 words
A conferencing bridge according to claim 10 further comprising means for attenuating contributions of each party to the input data by about three decibels.
Claim 19
Dependent Claim
60 words
A conferencing bridge according to claim 10 wherein said input and output PCM data are in eight bit compressed format and wherein said arithmetic logic means includes means for converting said eight bit compressed data to fourteen bit linear format prior to performing sample summations and subtractions and afterwards transforming the fourteen bit linear format back to 8-bit compressed format.
Claim 20
Dependent Claim
31 words
A conferencing bridge according to claim 10 wherein said algorithm comprises: phase inverting alternate parties; converting the data to fourteen bit two's-complement data; and summing the data creating a grand total.
Claim 21
Dependent Claim
25 words
A conferencing bridge according to claim 18 wherein said algorithm further comprises attenuating said fourteen bit two's-complement data by about three decibels whenever so commanded.
Claim 22
Dependent Claim
29 words
A conferencing bridge according to claim 18 wherein said algorithm further comprises generating a return signal for each party by subtracting each party's own contribution from said grand total.
Claim 23
Dependent Claim
35 words
A conferencing bridge according to claim 18 further comprising: generating a return signal for each party by subtracting each party's own contribution from said grand total; limiting the result; and converting back to μ law.
Claim 24
Dependent Claim
35 words
A conferencing bridge according to claim 18 further comprising: means for phase inverting alternate parties; means for converting the data to fourteen bit two's-complement data; and means for summing the data creating a grand total.
Claim 25
Dependent Claim
22 words
A conferencing bridge according to claim 22 further comprising means for selectively attenuating said fourteen bit two's-complement data by about three decibels.
Claim 26
Dependent Claim
28 words
A conferencing bridge according to claim 22 further comprising means for generating a return signal for each party by subtracting each party's own contribution from said grand total.
Claim 27
Dependent Claim
37 words
A conferencing bridge according to claim 22 further comprising: means for generating a return signal for each party by subtracting each party's own contribution from said grand total, limiting the result, and converting back to μ law.
Claim 28
Dependent Claim
35 words
A conferencing bridge according to claim 10 wherein said PCM outputs from said arithmetic logic means are directly input to said receiving means without passing through a PROM that accomodates arithmetic overflow and zero substitution.
Claim 29
Dependent Claim
156 words
A conferencing bridge for supporting a telephone conversation involving more than two parties wherein each party transmits a stream of unique PCM data bits and receives a stream of unique PCM data bits; comprising: input means for receiving first and second incoming serial PCM highways carrying said transmit and receive PCM data and converting data on said PCM highways to parallel data; a first RAM means for temporarily storing samples of said parallel data; a second RAM means for storing a command byte associated each of said parties to the conference, said first and second RAM means being the only RAM means required for the PCM highways: arithmetic means for implementing a conferencing algorithm by performing only arithmetic functions and producing PCM outputs; means for receiving the PCM outputs directly from said arithmetic means without passing through a PROM for minimal propagation delay, separating said outputs by highway, and converting said outputs to serial data streams.
Claim 30
Dependent Claim
156 words
A conferencing bridge for supporting a telephone conversation involving more than two parties wherein each party transmits a stream of unique PCM data bits and receives a stream of unique PCM data bits; comprising: input means for receiving first and second incoming serial PCM highways carrying said transmit and receive PCM data and converting data on said PCM highways to parallel data; a first RAM means for temporarily storing samples of said parallel data; a second RAM means for storing a command byte associated each of said parties to the conference, said first and second RAM means being the only RAM means required for the PCM highways: arithmetic means for implementing a conferencing algorithm by performing only arithmetic functions and producing PCM outputs; means for receiving the PCM outputs directly from said arithmetic means without passing through a PROM for minimal propagation delay, separating said outputs by highway, and converting said outputs to serial data streams.
Claim 31
Dependent Claim
21 words
A conferencing bridge according to claim 27 further comprising means for providing valid output PCM data when an arithmetic overflow occurs.
Claim 32
Dependent Claim
28 words
A conferencing bridge according to claim 28 wherein an overflow gate is enabled in response to an arithmetic overflow thereby substituting a positive or negative sixteen bit value.
Claim 33
Dependent Claim
22 words
A conferencing bridge according to claim 27 further comprising means for providing valid output PCM data when a sum is being cleared.
Claim 34
Dependent Claim
32 words
A conferencing bridge according to claim 30 wherein a zero is gated and latched instead of an adder result, if a reset bit is set true, when a sum is being cleared.
Claim 35
Dependent Claim
66 words
A conferencing bridge according to claim 27 wherein said input and output PCM data are in standard μ law companded format which is a piecewise linear approximation to a logarithmic curve and wherein said arithmetic means includes means for converting said input data to an equivalent linear format prior to performing sample summations and subtractions and afterwards transforming the data back to μ law companded format.
Claim 36
Dependent Claim
16 words
A conferencing bridge according to claim 32 wherein the equivalent linear format is signed two's complement.
Claim 37
Dependent Claim
19 words
A conferencing bridge according to claim 27 further comprising means for attenuating contributions of party to the input data.
Claim 38
Dependent Claim
24 words
A conferencing bridge according to claim 27 further comprising means for attenuating contributions of each party to the input data by about three decibels.
Claim 39
Dependent Claim
60 words
A conferencing bridge according to claim 27 wherein said input and output PCM data are in eight bit compressed format and wherein said arithmetic logic means includes means for converting said eight bit compressed data to fourteen bit linear format prior to performing sample summations and subtractions and afterwards transforming the fourteen bit linear format back to 8-bit compressed format.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-01-10 | 1992-07-11 | 1993-01-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-10 | 1996-07-11 | 1997-01-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-10 | 2000-07-11 | 2001-01-10 | $7700.00 | Window Closed / Lapsed |