US3764760A
Expired / Lapsed
US
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Method of and means for emitting interrogation codes to supervise repeaters of pcm telecommunication system
Assignee: Italtel SpA
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Filing: 1971-12-27
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Granted: 1973-10-09
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Expires: 1991-12-27
Abstract
Abstract To test the performance of several repeaters cascaded along a PCM telecommunication channel, a pulse generator at a terminal station is settable to emit bipolar pulse trains in which a balanced pulse pattern, recurring m times in succession, alternates with an unbalanced modification of that pulse pattern, recurring n times in succession; the total number of cycles (n+m) per repetitive pulse sequence is variable to address different repeaters with output filters tuned to the respective repetition frequencies. By altering the degree of unbalance in the second (m-cycle) portion of the pulse sequence, the fidelity of the regenerating operation of the interrogated repeater can be ascertained from the presence or absence of correlation between the number of odd pulses per cycle and the amplitude of the lowfrequency wave passed by the output filter.
Inventors
- 👤 D Marchini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 07:01
CPC Classifications
H; H04; H04B; H04B17/00; H04B17/40; H04B17/401; H04B17/406
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
210 words
A network for transmitting interrogation codes over a pulsecode-modulation channel to test the performance of a repeater inserted in said channel, comprising: timing means emitting a continuous train of clock pulses recurring at intervals t: pulse-generating means controlled by said timing means for iteratively producing a balanced basic pulse pattern with an equal number of positive and negative pulses in the rhythm of said clock pulses extending over a cycle T pt, P being an integer; a source of unbalancing pulses, timed to coincide with a selected portion of said basic pulse pattern, controlled by said timing means for alternate operation and nonoperation during m and n consecutive cycles T, respectively, thereby making unequal the number of positive and negative pulses in said selected portion; synthesizing means connected to receive said basic pulse pattern from said pulse-generating means and said unbalancing pulses from said source for combining same into a recurrent code sequence consisting of n cycles of a balanced pulse pattern of duration T followed by m cycles of the same pulse pattern modified by said unbalancing pulses; and selector means coupled to said source for altering the recurrence rate of said unbalancing pulses, thereby altering the degree of unbalance of the pulse pattern modified by said unbalancing pulses.
Claim 2
Dependent Claim
210 words
A network for transmitting interrogation codes over a pulsecode-modulation channel to test the performance of a repeater inserted in said channel, comprising: timing means emitting a continuous train of clock pulses recurring at intervals t: pulse-generating means controlled by said timing means for iteratively producing a balanced basic pulse pattern with an equal number of positive and negative pulses in the rhythm of said clock pulses extending over a cycle T pt, P being an integer; a source of unbalancing pulses, timed to coincide with a selected portion of said basic pulse pattern, controlled by said timing means for alternate operation and nonoperation during m and n consecutive cycles T, respectively, thereby making unequal the number of positive and negative pulses in said selected portion; synthesizing means connected to receive said basic pulse pattern from said pulse-generating means and said unbalancing pulses from said source for combining same into a recurrent code sequence consisting of n cycles of a balanced pulse pattern of duration T followed by m cycles of the same pulse pattern modified by said unbalancing pulses; and selector means coupled to said source for altering the recurrence rate of said unbalancing pulses, thereby altering the degree of unbalance of the pulse pattern modified by said unbalancing pulses.
Claim 3
Dependent Claim
53 words
A network as defined in claim 1 wherein said timing means includes a generator of said clock pulses and a multistage binary counter connected to said generator for stepping by said clock pulses, said pulse-generating means and said source comprising logical circuitry connected to said generator and to several stages of said counter.
Claim 4
Dependent Claim
94 words
A network as defined in claim 2 wherein said logical circuitry includes a first coincidence gate forming part of said pulse-generating means and producing a succession of paired unipolar first pulses constituting said basic pattern, said circuitry further including a plurality of second coincidence gates forming part of said source and producinG trains of differently spaced unipolar second pulses, said selector means being operable to derive said unbalancing pulses from the pulse trains passing any one of said second coincidence gates, said synthesizing means including inverter means for alternate ones of said paired pulses.
Claim 5
Dependent Claim
106 words
A network as defined in claim 3 wherein said synthesizer forms a pair of parallel paths for said first pulses, said inverter means including a pair of gates in said paths, a coupling stage connected across said paths beyond said gates and a flip-flop with a switching input connected to said pulse-generating means for alternately unblocking said gates whereby said first pulses alternately traverse said coupling stage in opposite directions, said synthesizer further comprising additional gate means in tandem with said pair of gates connected to said selector means for modifying the travel of said first pulses along said paths in response to said unbalancing pulses.
Claim 6
Dependent Claim
44 words
A network as defined in claim 4 wherein said additional gate means comprises an AND gate with a noninverting input for said first pulses and an inverting input for said unbalancing pulses, thereby stopping said first pulses in the presence of said unbalancing pulses.
Claim 7
Dependent Claim
48 words
A network as defined in claim 4 wherein said additional gate means comprises a pair of switching gates inserted between said flip-flop and said pair of gates for reversing the effect of said flip-flop upon the travel of said first pulses in the presence of said unbalancing pulses.
Claim 8
Dependent Claim
40 words
A network as defined in claim 4 wherein said timing means includes a square-wave generator under the control of said counter connected to said additional gate means for inhibiting said unbalancing pulses during said n cycles of a code sequence.
Claim 9
Dependent Claim
70 words
A network as defined in claim 7 wherein said square-wave generator comprises a second binary counter connected to be stepped by a stage output of the first-mentioned counter and provided with presetting means for emitting a switching signal upon a count of a selected number of cycles, and bistable means responsive to said signal for alternately switching said presetting means to establish said count alternately at m and n cycles.
Claim 10
Dependent Claim
55 words
A network as defined in claim 8 wherein said second counter has a capacity q at least equal to the maximum values of m and n, said presetting means including a logic matrix connected to said second counter for preloading same with a respective count of q-m and q-n in response to alternate switching signals.
Claim 11
Dependent Claim
26 words
A network as defined in claim 9 wherein said logic matrix is provided with enabling means selectively operable to establish various values for m and n.
Claim 12
Independent Claim
166 words
A method of testing the performance of a repeater in a pulse-code-modulation transmission channel, comprising the steps of: generating an interrogation code in the form of a sequence of bipolar pulses recurring with a predetermined repetition frequency which corresponds to a pass frequency of a filter in the output of the repeater to be tested, said sequence being divided into a balanced first part with an equal number of positive and negative pulses and an unbalanced second part with at least one pulse of one polarity unmatched by a pulse of the other polarity whereby a response signal at said repetition frequency is generated in the output of the properly functioning repeater; modifying the degree of unbalance of said second part by changing the number of unmatched pulses thereof; and comparing the amplitude of said response signal generated with different degrees of unbalance to determine the presence of correlation between said amplitudes and said degree of unbalance as a measure of the efficiency of the repeater.
Claim 13
Independent Claim
166 words
A method of testing the performance of a repeater in a pulse-code-modulation transmission channel, comprising the steps of: generating an interrogation code in the form of a sequence of bipolar pulses recurring with a predetermined repetition frequency which corresponds to a pass frequency of a filter in the output of the repeater to be tested, said sequence being divided into a balanced first part with an equal number of positive and negative pulses and an unbalanced second part with at least one pulse of one polarity unmatched by a pulse of the other polarity whereby a response signal at said repetition frequency is generated in the output of the properly functioning repeater; modifying the degree of unbalance of said second part by changing the number of unmatched pulses thereof; and comparing the amplitude of said response signal generated with different degrees of unbalance to determine the presence of correlation between said amplitudes and said degree of unbalance as a measure of the efficiency of the repeater.
Claim 14
Dependent Claim
23 words
A method as defined in claim 11, comprising the further step of varying said repetition frequency to test different repeaters in said channel.
Claim 15
Dependent Claim
60 words
A method as defined in claim 12 wherein the duration of said first part is a multiple nT and the duration of said second part is a multiple mT of a basic period T, said repetition frequency being varied by changing the value of (m+n) while holding the difference between m and n equal to at most one period T.
Claim 16
Dependent Claim
27 words
A method as defined in claim 11 wherein the step of modifying said degree of unbalance includes alternately suppressing pulses of both polarities in said second part.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-08 | 1977-04-09 | 1977-10-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-08 | 1981-04-09 | 1981-10-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-08 | 1985-04-09 | 1985-10-09 | $7700.00 | Window Closed / Lapsed |