EP0211675A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Line terminating apparatus
Assignee: Plessey Overseas Ltd
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Filing: 1986-08-08
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Granted: —
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Expires: 2006-08-08
Abstract
Abstract To provide facilities to handle many different types of customer line which may be connected to a telephone exchange each line circuit includes adjustable terminating and amplifying devices responsive to signals received from a control unit to adjust (e.g.) line terminating impedance and gain. The line circuits are grouped together with associated group multiplexers and address decoding facilities. Stored parameters held by the control unit may be dynamically updated in response to changes in line condition detected by power feed circuitry in the line circuits, the power feed circuitry being arranged to provide a constant current feed to the line pair and to send AGC signals reflecting increased or decreased line resistance by way of the respective group multiplexer to the control unit. Other facilities of the apparatus include provision of calling signals to line and the provision of subscriber private metering (SPM) signals. Each pulse of dialled digits is detected in the line circuit and multiplexed to the control unit which accumulates the dialled digits forwarding each complete digit to the communications exchange.
Inventors
- 👤 Christopher Charles Andrew Priest
- 👤 Ian Walker
- 👤 Steven Hancock
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 20:22
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/40; H04M3/005; H04Q; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
213 words
Line terminating apparatus comprising a control unit and a plurality of groups of n line circuits (where n is an integer of at least 2), each of said line circuits is arranged for connection to a respective line pair, said control unit comprising an interface for inter-communication of data with a processor controlled telecommunications exchange, a memory for storing data relating to line conditions of each connected line pair and processing means, each of said plurality of groups comprising at least one multiplexer arranged to concentrate at least one data parameter from the n respective line circuits in the group and address decoding means arranged to recognise addressing signals received from said control unit which signs indentify one of the n respective line circuits in the group and to enable a line circuit so addressed to interchange data with said control unit, said processing means being arranged to cause addressing of each line circuit at periodic intervals to transmit respective data parameters from said memory and to receive data relating to activity on the respective line pairs whereby line parameters initially specified by said processor controlled exchange are periodically refreshed in the line circuits and data received from the line circuits may be pre-processed and concentrated for forwarding to said processor controlled exchange.
Claim 2
Dependent Claim
213 words
Line terminating apparatus comprising a control unit and a plurality of groups of n line circuits (where n is an integer of at least 2), each of said line circuits is arranged for connection to a respective line pair, said control unit comprising an interface for inter-communication of data with a processor controlled telecommunications exchange, a memory for storing data relating to line conditions of each connected line pair and processing means, each of said plurality of groups comprising at least one multiplexer arranged to concentrate at least one data parameter from the n respective line circuits in the group and address decoding means arranged to recognise addressing signals received from said control unit which signs indentify one of the n respective line circuits in the group and to enable a line circuit so addressed to interchange data with said control unit, said processing means being arranged to cause addressing of each line circuit at periodic intervals to transmit respective data parameters from said memory and to receive data relating to activity on the respective line pairs whereby line parameters initially specified by said processor controlled exchange are periodically refreshed in the line circuits and data received from the line circuits may be pre-processed and concentrated for forwarding to said processor controlled exchange.
Claim 3
Dependent Claim
24 words
Line terminating apparatus as claimed in claim l wherein the stored data parameters include data parameters relating to loop conditions of each line pair.
Claim 4
Dependent Claim
31 words
Line terminating apparatus as claimed in claim 2 wherein said data parameters relating to loop conditions are used to adjust amplification of signals received from or sent to said line pairs.
Claim 5
Dependent Claim
41 words
Line terminating apparatus as claimed in claim l, claim 2 or claim 3 wherein said stored data parameters include data relating to terminating impedances for each line pair, such data being used to adjust programmable impedances connected across the line pairs.
Claim 6
Dependent Claim
62 words
Line terminating apparatus as claimed in any preceding claim wherein each line circuit includes two-wire to four-wire conversion circuitry for each line pair whereby signals received from such line pairs are forwarded to a connected communications exchange on a forward two wire circuit and signals received from such communications exchange on a reverse two wire circuit are forwarded to such line pairs.
Claim 7
Dependent Claim
61 words
Line terminating apparatus as claimed in claim 5 wherein each line circuit includes an analogue to digital conversion circuit and a digital to analogue conversion circuit whereby analogue signals received from the line pairs are converted to digital levels for forwarding to the exchange and digital signals received from the exchange are converted to analogue for forwarding to the line pairs.
Claim 8
Dependent Claim
43 words
Line terminating apparatus as claimed in claim 6 wherein said analogue to digital conversion circuit converts analogue signals to linear encoded pulse code modulated (pcm) digital signals and said digital to analogue conversion circuit converts linear encoded pcm digital signals to analogue signals.
Claim 9
Dependent Claim
32 words
Line terminating apparatus as claimed in claim 7 wherein pcm signals to and from the line circuits are time division multiplexed (tdm) onto a digital bus from and to the control unit.
Claim 10
Dependent Claim
81 words
Line terminating apparatus as claimed in claim 8 wherein the control unit includes a linear to A-law conversion circuit and an A-law to linear conversion circuit, said circuits respectively being arranged to convert a linear encoded pcm-tdm data stream from the line circuits to an A-law encoded pcm-tdm data stream for forwarding to the exchange and to convert an A-law encoded pcm-tdm data stream received from the exchange to a linear encoded pcm-tdm data stream for forwarding to the line circuits.
Claim 11
Dependent Claim
51 words
l0. Line terminating apparatus as claimed in any preceding claim wherein each line circuit includes switching means responsive to signals received from the processing means of the control unit to apply calling signals to the respective connected line pair whereby cadencing of calling signals may be programmed in said control unit.
Claim 12
Dependent Claim
35 words
Line terminating apparatus according to any preceding claim wherein each line circuit includes a power feed circuit which is responsive to conditions on the connected line pair to increase or decrease the voltage applied thereto.
Claim 13
Dependent Claim
51 words
Line terminating apparatus according to claim ll wherein said power feed circuit provides signals to said control unit reflecting loop resistance of the respective connected line pair, said control unit being arranged to modify the stored data parameters to increase or decrease gain settings to be applied in said line circuit.
Claim 14
Dependent Claim
32 words
Line terminating apparatus according to claim l2 wherein the signals from the power feed circuits are multiplexed in each group by said at least one mulitplexer for forwarding to the control unit.
Claim 15
Dependent Claim
33 words
Line terminating apparatus according to any preceding claim wherein said control unit includes tone generation means arranged to provide tones for application to the line pairs to effect operation of remote metering apparatus.
Claim 16
Dependent Claim
42 words
Line terminating apparatus according to claim l4 wherein each of said line units includes means operable in response to signals from said control unit to mix the signals from said tone generation means with speech signals forwarded to the connected line pair.
Claim 17
Dependent Claim
62 words
Line terminating apparatus according to any preceding claim wherein each of said line circuits includes means operable in response to signals received from said control unit to effect interconnection between the respective connected line pair and a line pair of the exchange whereby testing of the forward and reverse paths from the line circuit may be carried out by the exchange apparatus.
Claim 18
Dependent Claim
52 words
Line terminating apparatus according to any preceding claim wherein each of said line circuits includes detection means responsive to signals on the respective line pair which signals provide answer or calling indications to the exchange, said detector means providing signals to the control unit indicating a change of status of the line.
Claim 19
Dependent Claim
26 words
Line terminating apparatus according to claim l7 wherein the signals from the detection means are multiplexed in the group multiplexer for forwarding to the control unit.
Claim 20
Dependent Claim
30 words
Line terminating apparatus according to claim l7 or claim l8 wherein said detection means also detects signals relating to routing information which signals are received from the connnected line pair.
Claim 21
Dependent Claim
49 words
Line terminating apparatus according to claim l9 in which the control unit is arranged to accumulate the signals received by the detector means of each of said line circuits, said control unit forwarding the information to a connected exchange on receipt of a complete digit of such routing information.
References Cited (Backward Citations)
No citation records indexed.
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