US4918623A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Testing the performance of a communication line between two modems using modem processor
Assignee: Motorola Solutions Inc
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Filing: 1988-10-19
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Granted: 1990-04-17
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Expires: 2008-10-19
Abstract
Abstract Apparatus for testing the performance of a communication line that carries customer data between two modems, including a programmable processor (for example, a digital signal processor) in each modem that either performs modulation or demodulation of customer data or tests the line, and a controller (for example, a programmable host processor) that switches the programmable signal processor selectively between processing customer data and line testing. The communication line carries both customer data and network control commands that include a test command for initiating testing, and each host processor responds to the test command by switching the signal processor to the test mode. There are a plurality of modems forming a data network and a central network control system connected to the network for providing the test command. The test command names two of the modems to participate in the testing and the controller identifies whether a given modem is one of the participants. The controller causes all of the modems to cease processing customer data while the testing is in progress. The network carries progress signals while the testing is in progress. The controller causes all modems other than the two modems to monitor the network for the progress signals and to again process customer data when the progress signals cease to appear.
Inventors
- 👤 John A. Lockitt
- 👤 Kelly A. Lyndon
- 👤 Robert M. Wilson
- 👤 Bruce C. Giese
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:35
CPC Classifications
H; H04; H04L; H04L43/00; H04L43/50; G; G06; G06F; G06F11/00; G06F11/30; G06F11/34; G06F11/3466; G06F11/349; H04L1/00; H04L1/24
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
142 words
Apparatus for quantitatively testing the performance of a communication line that carries customer data in both directions between two modems, said communication line carrying both customer data and a test command for controlling said testing, said apparatus comprising a digital signal processor in each said modem coupled to said communication line for performing both digital modulation and demodulation of customer data carried on said line in accordance with a data program, and a series of quantitative tests of said line in accordance with a test program using test signal tones generated digitally, and in each said modem a programmable host processor separate from and coupled to said digital signal processor and responsive to said test command for selectively causing said digital signal processor to switch between performing said modulation and demodulation of customer data and said performing said series of quantitative tests.
Claim 2
Dependent Claim
142 words
Apparatus for quantitatively testing the performance of a communication line that carries customer data in both directions between two modems, said communication line carrying both customer data and a test command for controlling said testing, said apparatus comprising a digital signal processor in each said modem coupled to said communication line for performing both digital modulation and demodulation of customer data carried on said line in accordance with a data program, and a series of quantitative tests of said line in accordance with a test program using test signal tones generated digitally, and in each said modem a programmable host processor separate from and coupled to said digital signal processor and responsive to said test command for selectively causing said digital signal processor to switch between performing said modulation and demodulation of customer data and said performing said series of quantitative tests.
Claim 3
Dependent Claim
37 words
The apparatus of claim 1 further comprising a plurality of said modems coupled to said communication line to form a data network and a central network controller coupled to said communication line for providing said test command.
Claim 4
Dependent Claim
41 words
The apparatus of claim 2 wherein each said test command names two of said modems to participate in said testing, and said modem controller in each of said plurality of modems identifies whether each said modem is one of said participants.
Claim 5
Dependent Claim
87 words
The apparatus of claim 3 wherein said communication line of said network carries progress signals indicating that the testing is in progress, while said testing is in progress, said modem controllers in all said modems being responsive to said progress signals to cause said modems to cease modulating and demodulating customer data while said testing is in progress with all modems other than said two modems monitoring said network for said progress signals and again modulating and demodulating customer data when said progress signals cease to appear.
Claim 6
Dependent Claim
52 words
The apparatus of claim 2 wherein said central network controller generates a clear test command to indicate the end of the test, and one of said two modems responds to said clear test command by passing a clear test indication over said communication line to the other one of said two modems.
Claim 7
Dependent Claim
34 words
The apparatus of claim 5 wherein said clear test indication is passed by said one modem dropping a carrier signal for a period that is longer than a nominal quiescent period during said testing.
Claim 8
Dependent Claim
34 words
The apparatus of claim 1 wherein said central network controller discontinues the carrying of said customer data and said network control commands over said communication line temporarily beginning after said test command is received.
Claim 9
Dependent Claim
38 words
The apparatus of claim 1 further comprising a central network controller for said test command via said communication line to said two modems and wherein said modems return the results of said testing to said central network controller.
Claim 10
Dependent Claim
12 words
The apparatus of claim 1 wherein said line comprises a telephone line.
Claim 11
Dependent Claim
27 words
The apparatus of claim 1 wherein said customer data and said network control commands are respectively carried in two channels simultaneously over the same said communication line.
Claim 12
Dependent Claim
22 words
The apparatus of claim 10 wherein said customer data is carried in phase shift keyed form in a channel above 600 Hz.
Claim 13
Dependent Claim
22 words
The apparatus of claim 10 wherein said network commands are carried in frequency shift keyed form in a channel below 500 Hz.
Claim 14
Dependent Claim
13 words
The apparatus of claim 10 wherein said testing applies to both said channels.
Claim 15
Dependent Claim
41 words
The apparatus of claim 1 wherein said two modems each sends synchronizing signals to the other said modem on said communication line to synchronize said testing, and controls said testing based on said synchronizing signal received from the other said modem.
Claim 16
Dependent Claim
52 words
The apparatus of claim 14 wherein said communication line is characterized by a delay time for delivery of signals between said two modems, each said processor sends said test signals following said synchronizing signals, and said test signals are delayed, following said synchronizing signals, by a period longer than said delay time.
Claim 17
Dependent Claim
11 words
The apparatus of claim 1 wherein said performance includes signal-to-noise ratio.
Claim 18
Dependent Claim
11 words
The apparatus of claim 1 wherein said performance includes phase jitter.
Claim 19
Dependent Claim
11 words
The apparatus of claim 1 wherein said performance includes message noise.
Claim 20
Dependent Claim
11 words
The apparatus of claim 1 wherein said performance includes amplitude distortion.
Claim 21
Dependent Claim
18 words
The apparatus of claim 1 wherein said performance includes a delay of an envelope of a test signal.
Claim 22
Dependent Claim
11 words
The apparatus of claim 1 wherein said performance includes harmonic distortion.
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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) | 1993-04-16 | 1993-10-16 | 1994-04-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-16 | 1997-10-16 | 1998-04-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-16 | 2001-10-16 | 2002-04-17 | $7700.00 | Window Closed / Lapsed |