GB1498316A - Multiple connection device for a digital tdm switching centre - Google Patents
Multiple connection device for a digital tdm switching centreInfo
- Publication number
- GB1498316A GB1498316A GB1815376A GB1815376A GB1498316A GB 1498316 A GB1498316 A GB 1498316A GB 1815376 A GB1815376 A GB 1815376A GB 1815376 A GB1815376 A GB 1815376A GB 1498316 A GB1498316 A GB 1498316A
- Authority
- GB
- United Kingdom
- Prior art keywords
- subscriber
- samples
- store
- multiple connection
- speech
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04M—TELEPHONIC COMMUNICATION
- H04M3/00—Automatic or semi-automatic exchanges
- H04M3/42—Systems providing special services or facilities to subscribers
- H04M3/56—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities
- H04M3/561—Arrangements for connecting several subscribers to a common circuit, i.e. affording conference facilities by multiplexing
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04Q—SELECTING
- H04Q11/00—Selecting arrangements for multiplex systems
- H04Q11/04—Selecting arrangements for multiplex systems for time-division multiplexing
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Use Of Switch Circuits For Exchanges And Methods Of Control Of Multiplex Exchanges (AREA)
- Time-Division Multiplex Systems (AREA)
Abstract
1498316 Automatic exchange systems INTERNATIONAL STANDARD ELECTRIC CORP 4 May 1976 [7 May 1975] 18153/76 Heading H4K An electrical switching device for establishing a variable number of multiple connections, i.e. more than two parties, in a TDM digital switching centre, in which each party can be placed in any one of N states each corresponding to a particular type of connection, e.g. conference call, momentary isolation &c., comprises means for converting at an input, the non-linear codes of the samples into linear codes and conversely at an output, a store for storing recent samples, an adder for summing the most recent samples of all parties in each multiple connection and a subtractor for subtracting, in a particular time slot, the coded sample of the respective party from the sum of coded samples corresponding to the multiple connection involving said party. In a particular embodiment the device (2, Fig. 1, not shown) is connected to the time-space-time digital switch (1) of a TDM switching centre together with a plurality of subscribers (at least 256) each one of which is allocated to a time slot t (1-256) of a frame Tn; each time slot is divided into three phases tA, tB and tC. The device, Fig. 2, is connected to the switch (1) through a receive path R and a send path S through which all the subscribers taking part in multiple connections are connected to the device. The device includes registers 3, 14 for storing the incoming and outgoing speech samples respectively, a non-linear to linear code converter 6 and a linear to non-linear code converter 7, a speech memory 4 for storing the speech samples of each subscriber, an adder 18 for adding all the speech samples in a multiple connection, an accumulator 15 storing all the added samples, a subtractor 8 for subtracting a subscriber's own speech sample and a memory 19 which stores the addresses and states of all subscribers. Store 19 receives its information from the marker of the switching centre. Operation.-State El: temporary isolation; AND gates 5, 11 and 17 are disabled and no speech samples are written or read-out of accumulator 15 in a time slot thq hence the subscriber cannot be heard by and cannot listen to other parties. State E2: Conference call; at each time slot of frame Tn corresponding to a subscriber taking part in a conference call, memory 19 is addressed at tA, and memory 4 and accumulator 15 are read out at tB, and the samples from the previous frame T(n - 1) corresponding to a particular subscriber, (from store 4) and to a particular multiple connection (from accumulator 15) are fed to subtractor 8 which, at tC provides the sample to be sent to the subscriber corresponding to each slot. At tC, also, the speech sample from the same subscriber corresponding to frame Tn is stored in store 4 and also added to the output of subtractor 8 by adder 18 and stored in the accumulator 15. Thus all subscribers in each multiple connection can converse with each other. State E3: A subscriber can listen to other parties in a connection but he cannot be heard by the other parties. The operation is as for state E2 except that AND gates 5 are not enabled when the particular subscriber is addressed and thus his speech samples are not stored in store 4 or added to the contents of accumulator 15. State E4: A subscriber can hear only one party in a multiple connection but cannot be heard by any of the other parties. AND gates 5 and 17 are not enabled during the time slot corresponding to the subscriber and memory 19 does not contain the address of the multiple connection but of the particular party which the subscriber will listen to, so that the speech sample sent to the subscriber is that stored in store 4 in the address defined by store 19 and which corresponds to the particular party.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
FR7514401A FR2310669A1 (en) | 1975-05-07 | 1975-05-07 | MULTIPLE CONNECTION DEVICE FOR TIME-DISTRIBUTED DIGITAL SWITCHING CENTER |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1498316A true GB1498316A (en) | 1978-01-18 |
Family
ID=9154999
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB1815376A Expired GB1498316A (en) | 1975-05-07 | 1976-05-04 | Multiple connection device for a digital tdm switching centre |
Country Status (5)
Country | Link |
---|---|
BE (1) | BE841556A (en) |
CH (1) | CH615307A5 (en) |
DE (1) | DE2619555C2 (en) |
FR (1) | FR2310669A1 (en) |
GB (1) | GB1498316A (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0025225A1 (en) * | 1979-09-10 | 1981-03-18 | Western Electric Company, Incorporated | Broadcast and alternate message time slot interchanger |
GB2128448A (en) * | 1982-10-08 | 1984-04-26 | Standard Telephones Cables Ltd | Telephone exchange conference circuit |
GB2134751A (en) * | 1983-01-18 | 1984-08-15 | Plessey Co Plc | Conference bridge |
GB2146506A (en) * | 1983-09-08 | 1985-04-17 | Plessey Co Plc | Telephone conference bridge circuit arrangements |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2470495B1 (en) * | 1979-11-21 | 1988-06-24 | Int Standard Electric Corp | DIGITAL TELECOMMUNICATIONS SWITCHING SYSTEM CAPABLE OF ESTABLISHING MULTILATERAL TELECONFERENCE AND SELECTIVE INFORMATION OR SIGNAL BROADCAST CONNECTIONS |
DE3170917D1 (en) * | 1980-02-29 | 1985-07-18 | Ibm | Time division multiple access broadcasting, multipoint, and conferencing communication apparatus and method |
GB8301323D0 (en) * | 1983-01-18 | 1983-02-16 | Plessey Co Plc | Conference bridge |
US4570258A (en) * | 1984-02-13 | 1986-02-11 | Wang Laboratories, Inc. | Exchange switch |
Family Cites Families (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3551600A (en) * | 1968-02-23 | 1970-12-29 | Stromberg Carlson Corp | High capacity,high side-tone suppression,4-wire conference circuit |
DE2041605C3 (en) * | 1970-08-21 | 1980-04-24 | Telefonbau Und Normalzeit Gmbh, 6000 Frankfurt | Method for the establishment of inquiry calls in time-division multiplex switching equipment |
-
1975
- 1975-05-07 FR FR7514401A patent/FR2310669A1/en active Granted
-
1976
- 1976-05-03 CH CH551576A patent/CH615307A5/en not_active IP Right Cessation
- 1976-05-04 GB GB1815376A patent/GB1498316A/en not_active Expired
- 1976-05-04 DE DE19762619555 patent/DE2619555C2/en not_active Expired
- 1976-05-07 BE BE2055012A patent/BE841556A/en not_active IP Right Cessation
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0025225A1 (en) * | 1979-09-10 | 1981-03-18 | Western Electric Company, Incorporated | Broadcast and alternate message time slot interchanger |
GB2128448A (en) * | 1982-10-08 | 1984-04-26 | Standard Telephones Cables Ltd | Telephone exchange conference circuit |
US4566096A (en) * | 1982-10-08 | 1986-01-21 | Standard Telephones And Cables, Public Limited Company | Telephone exchange conference circuit |
GB2134751A (en) * | 1983-01-18 | 1984-08-15 | Plessey Co Plc | Conference bridge |
GB2146506A (en) * | 1983-09-08 | 1985-04-17 | Plessey Co Plc | Telephone conference bridge circuit arrangements |
Also Published As
Publication number | Publication date |
---|---|
DE2619555C2 (en) | 1984-10-11 |
FR2310669B1 (en) | 1981-06-19 |
CH615307A5 (en) | 1980-01-15 |
DE2619555A1 (en) | 1976-11-25 |
FR2310669A1 (en) | 1976-12-03 |
BE841556A (en) | 1976-11-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US4119807A (en) | Digital time division multiplex switching system | |
US4280217A (en) | Time division switching system control arrangement | |
US4224688A (en) | Digital conference circuit | |
US4190742A (en) | Process and apparatus for producing conference connections in a PCM time multiplex switching system | |
GB1498316A (en) | Multiple connection device for a digital tdm switching centre | |
JPH0238033B2 (en) | ||
US3736383A (en) | Multicustomer centralized call diverter | |
US3692947A (en) | Time division switching system conference circuit | |
WO1983002205A1 (en) | Demultiplexer circuit | |
GB1542794A (en) | Telephone and/or data network for mobile subscribers | |
GB1286909A (en) | Multi-stage time division multiplex highway switching network | |
US3268669A (en) | Common control for remote telephone switch units | |
GB1521127A (en) | Telecommunication systems | |
US3542965A (en) | Inter-office call diverter | |
EP0089716A1 (en) | Method of and arrangement for establishing a conference connection in a TDM communication system | |
US3812294A (en) | Bilateral time division multiplex switching system | |
US3050589A (en) | Multiplex signaling system | |
JPS5879365A (en) | Controller for absence transfer | |
SE316213B (en) | ||
EP0066576B1 (en) | A method and apparatus for transferring the same information to a plurality of subscribers | |
US3426158A (en) | Remote switch unit in a common control telephone system | |
US3395254A (en) | Pcm time division communication system conference circuit | |
US4013843A (en) | Marker for extending calls to remote junctions in a telecommunications system | |
US3904831A (en) | Tone control arrangement for electronic PABX | |
GB2009564A (en) | Telephone exchange apparatus providing short dialling |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
PCNP | Patent ceased through non-payment of renewal fee |