US5450438A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fallback method to 1200 bits per second for use in mobile radio
Assignee: Paradyne Corp
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Filing: 1993-07-26
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Granted: 1995-09-12
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Expires: 2013-07-26
Abstract
Abstract In a mobile data communications system, a near-end modem initiates a data connection to a far-end modem at the highest permissible data rate, e.g., at 9600 bits per second (bps). If the communications channel subsequently degrades, either the near-end modem, or the far-end modem, initiates an autorate, or fallback sequence, e.g., to 4800 bps. However, if channel performance is still poor at 4800 bps, then one, or both, of the modems initiate a fallback to 1200 bps--skipping over the data rate of 2400 bps, which is not included within the fallback sequence.
Inventors
- 👤 Joan E. Landry
- 👤 Mahendra Patel
- 👤 Robert E. Scott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:52
CPC Classifications
H; H04; H04M; H04M11/00; H04M11/06; H04L; H04L1/00; H04L1/20; H04W; H04W28/00; H04W28/16; H04W28/18; H04W28/22; H04L1/12; H04L1/16; H04L1/18; H04L1/1803; H04L1/1867; H04L1/188
Claims Analysis
Total Claims: 32
Claim 1
Independent Claim
67 words
An autorating method for use in a modem, the method comprising the steps of: receiving a data signal from a far-end modem at a data rate of at least 4800 bits per second; detecting an error condition in the data signal; responding to the detection of the error to change the data rate from the at least 4800 bits per second directly to 1200 bits per second.
Claim 2
Dependent Claim
67 words
An autorating method for use in a modem, the method comprising the steps of: receiving a data signal from a far-end modem at a data rate of at least 4800 bits per second; detecting an error condition in the data signal; responding to the detection of the error to change the data rate from the at least 4800 bits per second directly to 1200 bits per second.
Claim 3
Dependent Claim
31 words
The method of claim 1 wherein the received data signal represents a plurality of received packets and the error condition represents an error in at least one of the received packets.
Claim 4
Dependent Claim
48 words
The method of claim 1 wherein the received data signal represents a plurality of received packets and the error condition is the detection of the lack of an acknowledgment signal in these received packets for at least one prior transmitted packet from the modem to the far-end modem.
Claim 5
Dependent Claim
29 words
The method of claim 1 wherein the error condition represents a signal-to-noise ratio value for the received data signal that is higher than a predetermined signal-to-noise ratio reference value.
Claim 6
Dependent Claim
28 words
The method of claim 1 further including the step of demodulating a cellular carrier signal to provide the data signal before the step of receiving a data signal.
Claim 7
Dependent Claim
90 words
An autorating method for use in a modem, the method comprising the steps of: transmitting a data signal to a far-end modem at a data rate of at least 4800 bits per second, the data signal representing a plurality of data packets; detecting a lack of an acknowledgment signal for at least one of the plurality of data packets; and responding to the detection of the lack of an acknowledgment signal to change the data rate from the at least 4800 bits per second directly to 1200 bits per second.
Claim 8
Dependent Claim
90 words
An autorating method for use in a modem, the method comprising the steps of: transmitting a data signal to a far-end modem at a data rate of at least 4800 bits per second, the data signal representing a plurality of data packets; detecting a lack of an acknowledgment signal for at least one of the plurality of data packets; and responding to the detection of the lack of an acknowledgment signal to change the data rate from the at least 4800 bits per second directly to 1200 bits per second.
Claim 9
Dependent Claim
66 words
The method of claim 6 wherein the step of detecting a lack of an acknowledgment signal includes the step of: setting a timer for a predetermined amount of time for the at least one of the plurality of data packets; and reaching the end of said predetermined amount of time without receiving the acknowledgment signal for the at least one of the plurality of data packets.
Claim 10
Dependent Claim
31 words
The method of claim 7 wherein the step of transmitting the data signal includes the step of modulating a cellular carder with the data signal for transmission to the far-end modem.
Claim 11
Independent Claim
109 words
A method for providing an autorate feature in a modem comprising the steps of: receiving a data signal from a far-end modem at a data rate of at least 4800 bits per second; counting the errors in the data signal to provide an accumulated number of errors; comparing the accumulated number of errors to the predetermined threshold at the expiration of a time interval; and changing the data rate from the at least 4800 bits per second directly to 1200 bits per second so that the far-end modem transmits the data signal at 1200 bits per second if the number of detected errors is greater than a predetermined threshold.
Claim 12
Independent Claim
109 words
A method for providing an autorate feature in a modem comprising the steps of: receiving a data signal from a far-end modem at a data rate of at least 4800 bits per second; counting the errors in the data signal to provide an accumulated number of errors; comparing the accumulated number of errors to the predetermined threshold at the expiration of a time interval; and changing the data rate from the at least 4800 bits per second directly to 1200 bits per second so that the far-end modem transmits the data signal at 1200 bits per second if the number of detected errors is greater than a predetermined threshold.
Claim 13
Dependent Claim
28 words
The method of claim 9 wherein the step of receiving the data signal includes the step of recovering the data signal from a received modulated cellular carrier signal.
Claim 14
Independent Claim
90 words
A method for providing an autorate feature in a modem comprising the steps of: receiving a data signal from a far-end modem at a data rate of 1200 bits per second; and counting errors in the data signal to provide an accumulated number of errors; comparing the accumulated number of errors to the predetermined threshold at the expiration of the time interval; and changing the data rate from 1200 bits per second directly to 4800 bits per second if the accumulated number of errors is less than the predetermined threshold.
Claim 15
Independent Claim
90 words
A method for providing an autorate feature in a modem comprising the steps of: receiving a data signal from a far-end modem at a data rate of 1200 bits per second; and counting errors in the data signal to provide an accumulated number of errors; comparing the accumulated number of errors to the predetermined threshold at the expiration of the time interval; and changing the data rate from 1200 bits per second directly to 4800 bits per second if the accumulated number of errors is less than the predetermined threshold.
Claim 16
Dependent Claim
28 words
The method of claim 11 wherein the step of receiving the data signal includes the step of recovering the data signal from a received modulated cellular carrier signal.
Claim 17
Independent Claim
118 words
A method for use in a modem for initiating a data connection with a far-end modem, the method comprising the steps of: originating a telephone call to the far-end modem; detecting an answer tone from the far-end modem; initiating a training sequence with the far-end modem, where the training sequence occurs at a data rate of at least 4800 bits per second; setting a timer for a predetermined amount of time; generating a timer signal upon the expiration of the predetermined amount of time; and responding to the expiration of the predetermined amount of time by falling back from the at least 4800 bits per second data rate directly to a data rate of 1200 bits per second.
Claim 18
Independent Claim
118 words
A method for use in a modem for initiating a data connection with a far-end modem, the method comprising the steps of: originating a telephone call to the far-end modem; detecting an answer tone from the far-end modem; initiating a training sequence with the far-end modem, where the training sequence occurs at a data rate of at least 4800 bits per second; setting a timer for a predetermined amount of time; generating a timer signal upon the expiration of the predetermined amount of time; and responding to the expiration of the predetermined amount of time by falling back from the at least 4800 bits per second data rate directly to a data rate of 1200 bits per second.
Claim 19
Dependent Claim
36 words
The method of claim 13 wherein the step of initiating a training sequence includes the step of modulating a cellular carrier with a data signal that represents information that is a pan of the training sequence.
Claim 20
Dependent Claim
69 words
Apparatus for providing an autorating feature in a modem, comprising: means for receiving a data signal from a far-end modem at a data rate of at least 4800 bits per second; means for detecting an error condition in the data signal; means for responding to the detection of the error to change the data rate from the at least 4800 bits per second directly to 1200 bits per second.
Claim 21
Dependent Claim
69 words
Apparatus for providing an autorating feature in a modem, comprising: means for receiving a data signal from a far-end modem at a data rate of at least 4800 bits per second; means for detecting an error condition in the data signal; means for responding to the detection of the error to change the data rate from the at least 4800 bits per second directly to 1200 bits per second.
Claim 22
Dependent Claim
120 words
Apparatus for providing an autorating feature in a modem, comprising: means for transmitting a data signal to a far-end modem at a data rate of at least 4800 bits per second, the data signal representing a plurality of data packets; timer means for measuring a predetermined amount of time for at least one of the plurality of data frames and for providing an indication of the expiration of the predetermined amount of time; and means responsive to the indication of the expiration of the predetermined amount of time for the at least one of the plurality of data packets for changing the at least 4800 bits per second data rate of the data signal directly to 1200 bits per second.
Claim 23
Dependent Claim
120 words
Apparatus for providing an autorating feature in a modem, comprising: means for transmitting a data signal to a far-end modem at a data rate of at least 4800 bits per second, the data signal representing a plurality of data packets; timer means for measuring a predetermined amount of time for at least one of the plurality of data frames and for providing an indication of the expiration of the predetermined amount of time; and means responsive to the indication of the expiration of the predetermined amount of time for the at least one of the plurality of data packets for changing the at least 4800 bits per second data rate of the data signal directly to 1200 bits per second.
Claim 24
Dependent Claim
14 words
The apparatus of claim 16 wherein the means for transmitting includes a cellular transceiver.
Claim 25
Dependent Claim
84 words
Apparatus for providing an autorating feature in a modem, comprising: means for receiving a data signal from a far-end cellular modem at a data rate of at least 4800 bits per second; means for detecting errors in the data signal; and means for counting the detected errors and for changing the data rate from the data rate of at least 4800 bits per second directly to a data rate of 1200 bits per second when the count of detected errors exceeds a predetermined threshold.
Claim 26
Dependent Claim
84 words
Apparatus for providing an autorating feature in a modem, comprising: means for receiving a data signal from a far-end cellular modem at a data rate of at least 4800 bits per second; means for detecting errors in the data signal; and means for counting the detected errors and for changing the data rate from the data rate of at least 4800 bits per second directly to a data rate of 1200 bits per second when the count of detected errors exceeds a predetermined threshold.
Claim 27
Dependent Claim
14 words
The apparatus of claim 18 wherein the means for receiving includes a cellular transceiver.
Claim 28
Dependent Claim
66 words
The apparatus of claim 18 wherein the means for counting includes: processor means; and memory means for storing program data; where the processor executes the program data to a) count the detected errors and b) change the data rate of at least 4800 bits per second directly to a data rate of 1200 bits per second when the count of detected errors exceeds the predetermined threshold.
Claim 29
Dependent Claim
68 words
The apparatus of claim 20 wherein the processor means includes: a CPU means; and a timer means for providing a first time-out and a second time-out, where the expiration of the first-time out causes the CPU means to count the detected errors, and the expiration of the second time-out causes the CPU means to change the data rate when the count of detected errors exceeds the predetermined threshold.
Claim 30
Dependent Claim
95 words
Apparatus for use in a modem for establishing a data connection with a far-end modem, the apparatus comprising: means for initiating a training sequence with the far-end modem, where the training sequence occurs at a data rate of at least 4800 bits per second; timer means for measuring a predetermined amount of time and for providing a timer signal at the expiration of the predetermined amount of time; and means responsive to the timer signal for directly falling back to a data rate of 1200 bits per second if the training sequence is still active.
Claim 31
Dependent Claim
95 words
Apparatus for use in a modem for establishing a data connection with a far-end modem, the apparatus comprising: means for initiating a training sequence with the far-end modem, where the training sequence occurs at a data rate of at least 4800 bits per second; timer means for measuring a predetermined amount of time and for providing a timer signal at the expiration of the predetermined amount of time; and means responsive to the timer signal for directly falling back to a data rate of 1200 bits per second if the training sequence is still active.
Claim 32
Dependent Claim
14 words
The apparatus of claim 22 wherein the means for initiating includes a cellular transceiver.
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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) | 1998-09-11 | 1999-03-13 | 1999-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-09-11 | 2003-03-13 | 2003-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-09-11 | 2007-03-13 | 2007-09-12 | $7700.00 | Window Closed / Lapsed |