EP0206641A2
Expired / Lapsed
EP
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Telecommunications exchanges
Assignee: GPT Ltd
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Filing: 1986-06-11
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Granted: —
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Expires: 2006-06-11
Abstract
Abstract In a time division multiplexed digital switching system intercommunication between telephony groups is by way of a serially operated data bus (2). Allocation of bandwidth on'the data bus (2) is on a needs basis under control of a common control responsive (3) to requests from either applications processors or interface modules (10,20). The interface modules (10,20) receive addressing information from the common control (5) on a serially operated control bus (1) only when a change of status of a communication at least partly affecting that module - (10,20) occurs. Such changes of status include new communication set-ups, communication clear-down, bandwidth increase and bandwidth decrease. Dynamic re-allocation of bandwidth of the data bus (2) occurs without affecting communications in progress.
Inventors
- 👤 Paul Allan
- 👤 Keith Edmund Drage
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 23:14
CPC Classifications
H; H04; H04L; H04L12/00; H04L12/28; H04L12/40; H04L12/40006; H04L12/40019; H04L12/403; H04L12/4035; H04Q; H04Q11/00; H04Q11/04
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
127 words
A telecommunications exchange comprising a plurality of interface units having a respective plurality of communications terminals attached thereto wherein a common control allocates to each terminal a required channel bandwidth on the data bus, said bandwidth being defined by a start address and a stop address, the addresses being forwarded to the interface units on a control bus between the common control and the interface units, each of the interface units including means to identify the current address on the data bus, means to compare the current address with the respective start and stop addresses for each terminal thereon and means to cause the respective terminals to start or stop transmitting and/or receiving when identity between the current address and the allocated start or stop address occurs.
Claim 2
Dependent Claim
127 words
A telecommunications exchange comprising a plurality of interface units having a respective plurality of communications terminals attached thereto wherein a common control allocates to each terminal a required channel bandwidth on the data bus, said bandwidth being defined by a start address and a stop address, the addresses being forwarded to the interface units on a control bus between the common control and the interface units, each of the interface units including means to identify the current address on the data bus, means to compare the current address with the respective start and stop addresses for each terminal thereon and means to cause the respective terminals to start or stop transmitting and/or receiving when identity between the current address and the allocated start or stop address occurs.
Claim 3
Dependent Claim
66 words
A telecommunications exchange as claimed in claim 1 wherein each of the interface units has respective transmit start, transmit stop, receive start and receive stop registers in respect of each communications terminal thereon, each register addressing a respective comparator which is arranged to forward a start signal or a stop signal to a respective transmit or receive buffer associated with a respective one of the terminals.
Claim 4
Dependent Claim
120 words
A telecommunications exchange as claimed in claim 1 or claim 2 in which each of the interface units has a respective plurality of transmit start, transmit stop, receive start and receive stop registers in respect of each communications terminal thereon, each interface unit including respective transmit start, transmit stop, receive start and receive stop comparators arranged to provide start and stop signals to transmit and receive buffers associated with a respective one of the terminals, and switching means selects respective ones of the registers to provide signals to said comparison means in each cycle of the data bus whereby the bandwidth allocated to any particular terminal may be adjusted by signals from the central control without loss of communication occurring.
Claim 5
Dependent Claim
41 words
A telecommunications exchange as claimed in claim 1, claim 2 or claim 3 in which the current address of the data bus is identified by a counter which is responsive to clock pulses representing the transmission rate of the data bus.
Claim 6
Dependent Claim
28 words
A telecommunications exchange as claimed in claim 4 in which the counter is periodically adjusted in response to signals on the data bus identifying a particular address thereof.
Claim 7
Dependent Claim
42 words
A telecommunications exchange as claimed in any preceding claim in which each terrninal may be allocated a plurality of receive start and receive stop addresses whereby a receiving terminal may receive data from a plurality of transmitting terminals to permit multiway communications.
Claim 8
Dependent Claim
40 words
A telecommunications exchange as claimed in any one. of claims 1 to 5 in which the data bus is divided into two parallel buses to permit synchronous transmission and reception of data whereby respective transmit and receive addresses are identical.
References Cited (Backward Citations)
No citation records indexed.
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