Patent US3970799A successfully refreshed from Google Patents.
US3970799A
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Common control signaling extraction circuit
Assignee: AT&T Inc
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Filing: 1975-10-06
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Granted: 1976-07-20
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Expires: 1995-10-06
Abstract
Abstract A signaling extraction circuit utilizes common control circuitry to carry out the signal extraction function for all of a plurality of time multiplexed, digital data groups (digroups), each of which comprises 24 time division multiplexed, PCM encoded channels. Each digroup uses eight bits for transmitting digital information for each channel, but the eighth bit (D8) is borrowed for signaling purposes in every sixth frame. To identify these signaling digits, signaling frame information is inserted in a digroup bit stream in the framing bit position of every other frame (i.e., the subframes). A signaling subframe pattern store comprising a shared recirculating memory serves to maintain a continuing real time record of the pattern of the signaling framing information for each digroup, as well as a test digroup. When a predetermined pattern has been recorded for a digroup (i.e., a zero subframe bit preceded by a string of exactly three ones, or a one subframe bit preceded by a string of exactly three zeros) a signal bit store is enabled to receive the D8 bits of the signaling frame which follows the recording of said predetermined pattern.
Inventors
- 👤 John Robert Colton
- 👤 Robert Bruce Heick
- 👤 Henry Mann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:46
CPC Classifications
H; H04; H04J; H04J3/00; H04J3/02; H04J3/12; H04J3/06; H04J3/0602; H04Q; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
176 words
In a time division multiplex system wherein a plurality of digital groups of time division multiplexed channels are time multiplexed together on to a transmission link, each digital group including a similar predetermined framing bit pattern, each digital group using n-bits for transmitting digital information for each channel with the nth bit borrowed for signaling purposes in every mth frame, each digital group also including signaling framing bits in a given bit position of every f frames for the purpose of identifying the signaling bits of the group; a signaling extraction circuit characterized by signaling framing pattern store means including a shared recirculating memory for maintaining a continuing real time record of the pattern of the signaling framing bits for each digital group, a signal bit storage means for storing the nth signaling bit of each channel of each digital group, and means for enabling the signal bit storage means to receive the nth signaling bit of each chananel of a digital group after a predetermined signaling framing bit pattern has been recorded for the group.
Claim 2
Dependent Claim
176 words
In a time division multiplex system wherein a plurality of digital groups of time division multiplexed channels are time multiplexed together on to a transmission link, each digital group including a similar predetermined framing bit pattern, each digital group using n-bits for transmitting digital information for each channel with the nth bit borrowed for signaling purposes in every mth frame, each digital group also including signaling framing bits in a given bit position of every f frames for the purpose of identifying the signaling bits of the group; a signaling extraction circuit characterized by signaling framing pattern store means including a shared recirculating memory for maintaining a continuing real time record of the pattern of the signaling framing bits for each digital group, a signal bit storage means for storing the nth signaling bit of each channel of each digital group, and means for enabling the signal bit storage means to receive the nth signaling bit of each chananel of a digital group after a predetermined signaling framing bit pattern has been recorded for the group.
Claim 3
Dependent Claim
31 words
A signaling extraction circuit as defined in claim 1 including means for freezing the stored signaling bits of the channels of a digital group which is or about to be out-of-frame.
Claim 4
Dependent Claim
69 words
A signaling extraction circuit as defined in claim 1 including means for preventing the write in of the signaling bits of a digital group into the signal bit storage means when a frame deletion or repetition in the digital group signal is produced by the multiplex system, said write in being prevented until such time as a new predetermined signaling framing bit pattern has been recorded for the group.
Claim 5
Dependent Claim
39 words
A signaling extraction circuit as defined in claim 1 wherein the shared recirculating memory comprises a plurality of parallel shift registers that are clocked in time coincidence with the appearance of the digital groups on the multiplexed transmission link.
Claim 6
Dependent Claim
30 words
A signaling extraction circuit as defined in claim 4 wherein each of the shift registers comprises a number of cells that exceed by one the number of multiplex digital groups.
Claim 7
Dependent Claim
27 words
A time division system as defined in claim 1 wherein n = 8 and the least significant bit of each channel is periodically borrowed for signaling purposes.
Claim 8
Dependent Claim
32 words
A time division system as defined in claim 6 wherein m = 6 and f = 2, with the signaling framing bits positioned in the framing bit location of every other frame.
Claim 9
Dependent Claim
40 words
A signaling extraction circuit as defined in claim 1 wherein the signal bit storage means comprises a shared recirculating memory with a capacity to store the signaling bits of a signaling frame for each of the plurality of digital groups.
Claim 10
Dependent Claim
232 words
In a time division switching system wherein a plurality of digital groups of time division multiplexed channels are time multiplexed together on to a common bus, each digital group including a similar predetermined framing bit pattern, each digital group using n-bits for transmitting digital information for each channel with the least significant bit of each channel borrowed for signaling purposes in every mth frame, each digital group also including a predetermined pattern of signaling framing bits disposed in the framing bit positions of every other frame for the purpose of identifying the signaling bits of the group, a signaling extraction circuit comprising signaling framing pattern store means coupled to the common bus and including a shared recirculating memory for maintaining a continuing real time record of the pattern of the signaling framing bits for each digital group, signaling bit storage means including a shared recirculating memory with a capacity to store the signaling bits of a mth frame for each of the plurality of digital groups, and gating means coupled to said pattern store means for enabling the signaling bit storage means to receive the signaling bits of the channels of a digital group after a predetermined signaling framing bit pattern has been recorded for the group, said gating means further serving to freeze the stored signaling bits of the channels of a digital group during an out-of-frame condition of the same.
Claim 11
Dependent Claim
232 words
In a time division switching system wherein a plurality of digital groups of time division multiplexed channels are time multiplexed together on to a common bus, each digital group including a similar predetermined framing bit pattern, each digital group using n-bits for transmitting digital information for each channel with the least significant bit of each channel borrowed for signaling purposes in every mth frame, each digital group also including a predetermined pattern of signaling framing bits disposed in the framing bit positions of every other frame for the purpose of identifying the signaling bits of the group, a signaling extraction circuit comprising signaling framing pattern store means coupled to the common bus and including a shared recirculating memory for maintaining a continuing real time record of the pattern of the signaling framing bits for each digital group, signaling bit storage means including a shared recirculating memory with a capacity to store the signaling bits of a mth frame for each of the plurality of digital groups, and gating means coupled to said pattern store means for enabling the signaling bit storage means to receive the signaling bits of the channels of a digital group after a predetermined signaling framing bit pattern has been recorded for the group, said gating means further serving to freeze the stored signaling bits of the channels of a digital group during an out-of-frame condition of the same.
Claim 12
Dependent Claim
69 words
A signaling extraction circuit as defined in claim 9 including means for preventing the write in of the signaling bits of a digital group into the signaling bit storage means when a frame deletion or repetition in the digital group signal is produced by the multiplex system, said write in being prevented until such time as a new predetermined signaling framing bit pattern has been recorded for the group.
Claim 13
Dependent Claim
171 words
In a time division multiplex system wherein a plurality of digital groups of time division multiplexed channels are time multiplexed together on to a transmission link, each digital group including a similar predetermined framing bit pattern, each digital group using n-bits for transmitting digital information for each channel with the nth bit borrowed for signaling purposes in every mth frame, each digital group also including signaling framing bits in a given bit position of every f frames for the purpose of identifying the signaling bits of the group; a signaling extraction circuit characterized by signaling framing pattern store means for maintaining a continuing real time record of the pattern of the signaling framing bits for each digital group, a signal bit storage means for storing the nth signaling bit of each channel of each digital group, and means for enabling the signal bit storage means to receive the nth signaling bit of each channel of a digital group after a predetermined signaling framing bit pattern has been recorded for the group.
Claim 14
Dependent Claim
171 words
In a time division multiplex system wherein a plurality of digital groups of time division multiplexed channels are time multiplexed together on to a transmission link, each digital group including a similar predetermined framing bit pattern, each digital group using n-bits for transmitting digital information for each channel with the nth bit borrowed for signaling purposes in every mth frame, each digital group also including signaling framing bits in a given bit position of every f frames for the purpose of identifying the signaling bits of the group; a signaling extraction circuit characterized by signaling framing pattern store means for maintaining a continuing real time record of the pattern of the signaling framing bits for each digital group, a signal bit storage means for storing the nth signaling bit of each channel of each digital group, and means for enabling the signal bit storage means to receive the nth signaling bit of each channel of a digital group after a predetermined signaling framing bit pattern has been recorded for the group.
References Cited (Backward Citations)
US3166734A
Cited
US3401235A
Cited
US3796835A
Cited
US3872257A
Cited
US3909540A
Cited
US3931473A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-07-20 | 1980-01-19 | 1980-07-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-07-20 | 1984-01-19 | 1984-07-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-07-20 | 1988-01-19 | 1988-07-20 | $7700.00 | Window Closed / Lapsed |