US5835538A
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US
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High speed communications system for analog subscriber connections
Assignee: TOWNSHEND INTELLECTUAL PROPERTY LLC
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Filing: 1996-09-06
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Granted: 1998-11-10
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Expires: 2016-09-06
Abstract
Abstract A new data communication system is described which enables data transmission over existing telephone lines at rates higher than possible with existing methods, including conventional modems. By using a novel asymmetric configuration of the two communication endpoints, the currently-accepted maximum theoretical limits on the data rate are no longer applicable. One endpoint is connected directly to a digital telephone network, whereas the other endpoint uses a conventional telephone connection. This reduces the transmission problem to compensation for a single telephone line interface and a single analog local loop. Means of providing this compensation and the required clock synchronization were also created, enabling a practical implementation of the system. The new system can achieve rates up to 64,000 bits-per-second and has broad utility in several active areas including wide-band audio transmission, video transmission, networking, facsimile transmission, and remote computer access.
Inventors
- 👤 Brent Townshend
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:12
CPC Classifications
H; H04; H04L; H04L7/00; H04L7/0016; H04L7/002; H04L7/0029; H04L25/00; H04L25/38; H04L25/40; H04L25/49; H04L25/4917; H04L25/4927; H04L5/00; H04L5/14; H04L5/1438; H04M; H04M11/00; H04M11/06; H04Q; H04Q11/00; H04Q11/04; H04Q11/0428; H04Q2213/00; H04Q2213/13034; H04Q2213/13036; H04Q2213/1305; H04Q2213/1309; H04Q2213/13103; H04Q2213/13107; H04Q2213/13174; H04Q2213/13179; H04Q2213/13199; H04Q2213/13202; H04Q2213/13204; H04Q2213/13209; H04Q2213/13299; H04Q2213/1332; H04Q2213/13337; H04Q2213/1336; H04Q2213/13385; H04Q2213/13396
Claims Analysis
Total Claims: 43
Claim 1
Independent Claim
87 words
A high speed data transfer encoder that generates digital signals for transmission over a digital telephone network and an analog loop to a subscriber, comprising: a converter that converts a source data stream into a sequence of codewords selected from a predetermined set of codewords corresponding to quantization values utilized by said telephone network, said converter comprising a serial to parallel converter and a compensator coupled to said serial to parallel converter; and an interface to the digital telephone network, said interface being coupled to the compensator.
Claim 2
Dependent Claim
87 words
A high speed data transfer encoder that generates digital signals for transmission over a digital telephone network and an analog loop to a subscriber, comprising: a converter that converts a source data stream into a sequence of codewords selected from a predetermined set of codewords corresponding to quantization values utilized by said telephone network, said converter comprising a serial to parallel converter and a compensator coupled to said serial to parallel converter; and an interface to the digital telephone network, said interface being coupled to the compensator.
Claim 3
Dependent Claim
18 words
A high speed data transfer encoder as claimed in claim 1, wherein said compensator comprises a DC eliminator.
Claim 4
Dependent Claim
29 words
A high speed data transfer encoder as claimed in claim 2, wherein said DC eliminator modifies said sequence by inserting DC restoration codewords into said sequence at regular intervals.
Claim 5
Dependent Claim
101 words
A high speed data transfer encoder that generates digital signals for transmission over a digital telephone network and an analog loop to a subscriber, comprising: a converter for converting a source data stream into a sequence of codewords selected from a predetermined set of codewords, wherein said predetermined set of codewords comprises a subset of digital telephone network codewords, said digital telephone network codewords corresponding to a set of quantization values applied in a line interface which couples said digital telephone network to said analog loop; and an interface to the digital telephone network, said interface being coupled to said converter.
Claim 6
Dependent Claim
101 words
A high speed data transfer encoder that generates digital signals for transmission over a digital telephone network and an analog loop to a subscriber, comprising: a converter for converting a source data stream into a sequence of codewords selected from a predetermined set of codewords, wherein said predetermined set of codewords comprises a subset of digital telephone network codewords, said digital telephone network codewords corresponding to a set of quantization values applied in a line interface which couples said digital telephone network to said analog loop; and an interface to the digital telephone network, said interface being coupled to said converter.
Claim 7
Dependent Claim
23 words
A high speed data transfer encoder as claimed in claim 4, wherein said digital telephone network codewords comprise a set of 255 codewords.
Claim 8
Dependent Claim
21 words
A high speed data transfer encoder as claimed in claim 4, wherein said digital telephone network codewords comprise μ-law encoded codewords.
Claim 9
Dependent Claim
19 words
A high speed data transfer encoder as claimed 4, wherein said digital telephone network codewords comprise A-law encoded codewords.
Claim 10
Dependent Claim
87 words
A high speed data transfer encoder that generates digital signals for transmission over a digital telephone network and an analog loop to a subscriber, comprising: a converter that converts a source data stream into a sequence of codewords selected from a predetermined set of codewords, wherein said predetermined set of codewords is determined based upon a transfer characteristic of said analog loop and corresponding to quantization values utilized by said telephone network; and an interface to the digital telephone network, said interface being coupled to said converter.
Claim 11
Dependent Claim
87 words
A high speed data transfer encoder that generates digital signals for transmission over a digital telephone network and an analog loop to a subscriber, comprising: a converter that converts a source data stream into a sequence of codewords selected from a predetermined set of codewords, wherein said predetermined set of codewords is determined based upon a transfer characteristic of said analog loop and corresponding to quantization values utilized by said telephone network; and an interface to the digital telephone network, said interface being coupled to said converter.
Claim 12
Dependent Claim
19 words
A high speed data transfer encoder as claimed in claim 8, further comprising a demodulator coupled to said interface.
Claim 13
Dependent Claim
24 words
A high speed data transfer encoder as claimed in claim 9, wherein said demodulator receives a digital input and produces a digital output signal.
Claim 14
Dependent Claim
26 words
A high speed data transfer encoder as claimed in claim 10, wherein said converter adjusts said set of codewords in accordance with said digital output signal.
Claim 15
Dependent Claim
23 words
A high speed data transfer encoder as claimed in claim 9, further comprising an echo canceler coupled between said converter and said demodulator.
Claim 16
Dependent Claim
101 words
A high speed data transfer encoder for producing a sequence of digital codewords for transmission, over a digital connection to a digital telephone network and a single analog loop, to a subscriber, comprising: a converter having an input and an output, said input being coupled to receive a digital data stream; and an interface coupled between the output of said converter and said digital telephone network; wherein said encoder produces said sequence of digital codewords in response to receiving said digital data stream and each of said codewords is associated with a predetermined quantizing level utilized by said digital telephone network.
Claim 17
Dependent Claim
101 words
A high speed data transfer encoder for producing a sequence of digital codewords for transmission, over a digital connection to a digital telephone network and a single analog loop, to a subscriber, comprising: a converter having an input and an output, said input being coupled to receive a digital data stream; and an interface coupled between the output of said converter and said digital telephone network; wherein said encoder produces said sequence of digital codewords in response to receiving said digital data stream and each of said codewords is associated with a predetermined quantizing level utilized by said digital telephone network.
Claim 18
Dependent Claim
23 words
A high speed data transfer encoder as claimed in claim 13, further comprising a DC eliminator coupled to the output of the converter.
Claim 19
Dependent Claim
27 words
A high speed data transfer encoder as claimed in claim 14, wherein said DC eliminator comprises a selector and a means for generating a DC restoration codeword.
Claim 20
Dependent Claim
32 words
A high speed data transfer encoder as claimed in claim 15, wherein said selector selects one of the output of the converter and the DC restoration codeword for coupling to the interface.
Claim 21
Dependent Claim
84 words
A high speed data transfer encoder for generating a plurality of digital signals for transmission over a digital telephone network to a plurality of analog subscribers, comprising: means for converting at least two source data streams into at least two corresponding sequences of codewords selected from a predetermined set of codewords corresponding to quantization values utilized by said telephone network; a server connection coupling said converting means to said digital telephone network; and a compensator coupled between said converting means and said server connection.
Claim 22
Dependent Claim
84 words
A high speed data transfer encoder for generating a plurality of digital signals for transmission over a digital telephone network to a plurality of analog subscribers, comprising: means for converting at least two source data streams into at least two corresponding sequences of codewords selected from a predetermined set of codewords corresponding to quantization values utilized by said telephone network; a server connection coupling said converting means to said digital telephone network; and a compensator coupled between said converting means and said server connection.
Claim 23
Dependent Claim
44 words
A high speed data transfer encoder as claimed in claim 17, wherein said converting means comprising an array of digital signal processors, each of said array of digital signal processors coupled to receive a different one of said at least two source data streams.
Claim 24
Dependent Claim
29 words
A high speed data transfer encoder as claimed in claim 17, further comprising means for demodulating a digital signal received by said server connection from said digital telephone network.
Claim 25
Dependent Claim
20 words
A high speed data transfer encoder as claimed in claim 17, wherein said server connection comprises and ISDN PRI interface.
Claim 26
Dependent Claim
105 words
A high speed data transfer encoder for generating a plurality of digital signals for transmission over a digital telephone network to a plurality of analog subscribers, comprising: means for converting at least two source data streams into at least two corresponding sequences of codewords selected from a predetermined set of codewords, wherein said predetermined set of codewords comprises a subset of digital telephone network codewords, said digital telephone network codewords corresponding to a set of quantization values applied in a line interface which couples said digital telephone network to said analog subscribers; and a server connection coupling said converting means to said digital telephone network.
Claim 27
Dependent Claim
105 words
A high speed data transfer encoder for generating a plurality of digital signals for transmission over a digital telephone network to a plurality of analog subscribers, comprising: means for converting at least two source data streams into at least two corresponding sequences of codewords selected from a predetermined set of codewords, wherein said predetermined set of codewords comprises a subset of digital telephone network codewords, said digital telephone network codewords corresponding to a set of quantization values applied in a line interface which couples said digital telephone network to said analog subscribers; and a server connection coupling said converting means to said digital telephone network.
Claim 28
Dependent Claim
136 words
A high speed data transfer encoding method for communicating from a data source to a subscriber, wherein said subscriber is connected to a digital telephone network by an analog loop and said data source is connected through a digital connection to said digital telephone network, said method comprising the steps of: selecting a subset of digital codewords from a set of digital telephone network codewords, said digital telephone network codewords corresponding to a set of quantization values applied at a line interface which couples said digital telephone network to said analog loop; converting a data stream produced by said data source into a sequence of digital codewords from said subset of digital codewords; sampling said sequence of digital codewords at a predetermined rate; and transmitting said samples through said digital connection to said digital telephone network.
Claim 29
Dependent Claim
136 words
A high speed data transfer encoding method for communicating from a data source to a subscriber, wherein said subscriber is connected to a digital telephone network by an analog loop and said data source is connected through a digital connection to said digital telephone network, said method comprising the steps of: selecting a subset of digital codewords from a set of digital telephone network codewords, said digital telephone network codewords corresponding to a set of quantization values applied at a line interface which couples said digital telephone network to said analog loop; converting a data stream produced by said data source into a sequence of digital codewords from said subset of digital codewords; sampling said sequence of digital codewords at a predetermined rate; and transmitting said samples through said digital connection to said digital telephone network.
Claim 30
Dependent Claim
25 words
A high speed data transfer encoding method as claimed in claim 22, wherein said digital telephone network codewords comprise PCM representations of said quantization values.
Claim 31
Dependent Claim
26 words
A high speed data transfer encoding method as claimed in claim 23, wherein said quantization values are μ-law quantization values utilized by said digital telephone network.
Claim 32
Dependent Claim
27 words
A high speed data transfer encoding method as claimed in claim 22, wherein said predetermined rate corresponds to a clock rate utilized by said digital telephone network.
Claim 33
Dependent Claim
21 words
A high speed data transfer encoding method as claimed in claim 22, wherein said predetermined rate is 8000 samples per second.
Claim 34
Dependent Claim
47 words
A high speed data transfer encoding method as claimed in claim 22, further comprising the step of inserting a compensating codeword into said sequence of codewords, said compensating codeword altering a frequency component of a resulting analog signal generated at said line interface to said analog loop.
Claim 35
Dependent Claim
20 words
A high speed data transfer encoding method as claimed in claim 27, wherein said frequency component is a DC component.
Claim 36
Dependent Claim
33 words
A high speed data transfer encoding method as claimed in claim 22, wherein said selection of said subset of digital codewords is made in accordance with a characteristic of said digital telephone network.
Claim 37
Dependent Claim
36 words
A high speed data transfer encoding method as claimed in claim 29, wherein said characteristic comprises periodically substituting a digital telephone network synchronization bit for a bit in a codeword from said sequence of digital codewords.
Claim 38
Dependent Claim
32 words
A high speed data transfer encoding method as claimed in claim 22, wherein said selection of said subset of digital codewords is made in accordance with a characteristic of said analog loop.
Claim 39
Dependent Claim
23 words
A high speed data transfer encoding method as claimed in claim 31, wherein said characteristic of said analog loop comprises transmission line distortion.
Claim 40
Dependent Claim
40 words
A high speed data transfer encoding method as claimed in claim 22, wherein said selection of said subset of digital codewords is made in accordance with a characteristic of said digital telephone network and a characteristic of said analog loop.
Claim 41
Dependent Claim
33 words
A high speed data transfer encoding method as claimed in claim 22, wherein said data stream is transmitted as said sequence of digital codewords at an uncompressed rate in excess of 33 kbps.
Claim 42
Dependent Claim
141 words
A high speed data transfer encoder for communicating digital data to a recipient coupled to a digital telephone network by an analog subscriber line, comprising: a converter for receiving said digital data and for converting said digital data into a sequence of codewords selected from a set of codewords associated with a digital-to-analog converter located at an interface between said digital telephone network and said analog subscriber line and corresponding to quantization values utilized by said telephone network; a DC eliminator coupled to said converter, said DC eliminator comprising a two-input selector having an output, wherein a first input to said two-input selector is coupled to said converter and a second input to said two-input selector is coupled to said output by a summer; and an interface for digitally coupling the output of the two-input selector to said digital telephone network.
Claim 43
Dependent Claim
141 words
A high speed data transfer encoder for communicating digital data to a recipient coupled to a digital telephone network by an analog subscriber line, comprising: a converter for receiving said digital data and for converting said digital data into a sequence of codewords selected from a set of codewords associated with a digital-to-analog converter located at an interface between said digital telephone network and said analog subscriber line and corresponding to quantization values utilized by said telephone network; a DC eliminator coupled to said converter, said DC eliminator comprising a two-input selector having an output, wherein a first input to said two-input selector is coupled to said converter and a second input to said two-input selector is coupled to said output by a summer; and an interface for digitally coupling the output of the two-input selector to said digital telephone network.
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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) | 2001-11-09 | 2002-05-11 | 2002-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-09 | 2006-05-11 | 2006-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-09 | 2010-05-11 | 2010-11-10 | $7700.00 | Window Closed / Lapsed |