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US3692964A
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Remote-testing arrangement for two-way transmission channel of pcm telecommunication system
Assignee: Italtel SpA
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Filing: 1970-12-21
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Granted: 1972-09-19
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Expires: 1990-12-21
Abstract
Abstract To test several repeaters in a two-way transmission channel designed for pulse-code-modulation message signals, an identification code individual to a given repeater is sent out from a terminal station over one signal path and is picked up by a decoder at that repeater which, in response to several recurrences of the same code, closes a loop through the other signal path for feeding the code back to the originating station. The identification code is inserted four times in a binary sequency, sandwiched between guard codes of first-order and second-order periodicity to limit the possibility of accidental formation within the sequence of a code assigned to a different repeater.
Inventors
- 👤 Roberto Camiciottoli
- 👤 Maurizio Palombari
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:05
CPC Classifications
H; H04; H04B; H04B17/00; H04B17/40; H04B17/401; H04B17/406
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
275 words
In a pulse-code-modulation telecommunication system including a two-way transmission channel with a pair of signal paths extending from a local station to a remote station and with a multiplicity of intervening repeater stations in series each provided with amplifier means in said path, the combination therewith of: pulse-generating means including a multidigit selector at said local station for establishing a multiplicity of different identification codes of n bits each, n being an integer greater than 1, assigned to respective repeater stations and for iteratively transmitting a predetermined sequence of bits over one path of said channel, said sequence including one of said identification codes individual to a selected repeater station, said pulse-generating means further including a programmer controlled by said selector for repeating each identification code several times in said sequence with intervening multidigit guard codes of periodic character having a low-order periodicity with a recurrence period of m bits where m is substantially smaller than n; decoding means at said repeater station connected to said one path for picking up said identification code; switch means at said repeater station responsive to recognition of said identification code by said decoding means for completing a loop through said amplifier means back to said local station by way of the other path of said channel and for feeding back a recurrence of said sequence via said loop; detector means at said local station connected to said other path for receiving and recognizing said identification code, said detector means being coupled to said selector for registration of a replica of the transmitted code; and signaling means controlled by said detector means for indicating the closure of said loop.
Claim 2
Dependent Claim
275 words
In a pulse-code-modulation telecommunication system including a two-way transmission channel with a pair of signal paths extending from a local station to a remote station and with a multiplicity of intervening repeater stations in series each provided with amplifier means in said path, the combination therewith of: pulse-generating means including a multidigit selector at said local station for establishing a multiplicity of different identification codes of n bits each, n being an integer greater than 1, assigned to respective repeater stations and for iteratively transmitting a predetermined sequence of bits over one path of said channel, said sequence including one of said identification codes individual to a selected repeater station, said pulse-generating means further including a programmer controlled by said selector for repeating each identification code several times in said sequence with intervening multidigit guard codes of periodic character having a low-order periodicity with a recurrence period of m bits where m is substantially smaller than n; decoding means at said repeater station connected to said one path for picking up said identification code; switch means at said repeater station responsive to recognition of said identification code by said decoding means for completing a loop through said amplifier means back to said local station by way of the other path of said channel and for feeding back a recurrence of said sequence via said loop; detector means at said local station connected to said other path for receiving and recognizing said identification code, said detector means being coupled to said selector for registration of a replica of the transmitted code; and signaling means controlled by said detector means for indicating the closure of said loop.
Claim 3
Dependent Claim
32 words
The combination defined in claim 1 wherein said programmer includes circuitry for alternating between a predetermined number of mutually different but individually invariable guard codes in a fixed order within said sequence.
Claim 4
Dependent Claim
33 words
The combination defined in claim 2 wherein said decoding means comprises an integrating circuit responsive to a multiplicity of recurrences of said identification code at the rate of recurrence thereof in said sequence.
Claim 5
Dependent Claim
44 words
The combination defined in claim 3 wherein said decoding means comprises an n-stage shift register and a coincidence gate with n inputs respectively connected to the stages of said shift register, said integrating circuit being connected to receive the output of said coincidence gate.
Claim 6
Dependent Claim
32 words
The combination defined in claim 2 wherein said detector means comprises an n-stage comparison network settable by said selector and a shift register with n stages having output connections to said network.
Claim 7
Dependent Claim
65 words
The combination defined in claim 5 wherein said detector means further comprises a coincidence gate with n inputs respectively connected to the stages of said shift register and an integrating circuit inserted between said coincidence gate and said signaling means for actuating the latter only in response to a multiplicity of recurrences of said identification code at the rate of recurrence thereof in said sequence.
Claim 8
Dependent Claim
82 words
The combination defined in claim 1 wherein said programmer comprises a source of clock pulses, a counter for said clock pulses with n+p stages where p is substantially greater than n, an n-stage shift register with input connections to the stages thereof energizable by said selector, and logical circuitry jointly controlled by said source and said counter for periodically stepping said stages, said circuitry including blocking means for disabling said input connections upon said counter registering a pulse count other than n+p.
Claim 9
Dependent Claim
55 words
The combination defined in claim 7 wherein said circuitry further includes switchover means inserted between said source and a first one of said stages for alternately feeding 0''s and 1''s thereto in the disabled condition of said input circuitry, and binary means settable in certain counting cycles of each sequence for inhibiting said switchover means.
Claim 10
Dependent Claim
20 words
The combination defined in claim 2 wherein m 2 and the number of said mutually different guard codes equals 4.
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) | 1975-09-19 | 1976-03-20 | 1976-09-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-19 | 1980-03-20 | 1980-09-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-19 | 1984-03-20 | 1984-09-19 | $7700.00 | Window Closed / Lapsed |