GB1409610A - Telephone exchanges - Google Patents
Telephone exchangesInfo
- Publication number
- GB1409610A GB1409610A GB4916872A GB4916872A GB1409610A GB 1409610 A GB1409610 A GB 1409610A GB 4916872 A GB4916872 A GB 4916872A GB 4916872 A GB4916872 A GB 4916872A GB 1409610 A GB1409610 A GB 1409610A
- Authority
- GB
- United Kingdom
- Prior art keywords
- linear
- code
- bit
- conferee
- pcm
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Multimedia (AREA)
- Signal Processing (AREA)
- Interconnected Communication Systems, Intercoms, And Interphones (AREA)
Abstract
1409610 Automatic exchange systems POST OFFICE 17 Jan 1974 [25 Oct 1972] 49168/72 Heading H4K In a PCM, TDM conference circuit for conferencing more than three subscribers, a translator converts non-linear PCM code words representing the speech of each conferee into linear PCM code words. For each conferee the linear code words of the other conferees are added together and the sum is then converted into a non-linear PCM code for transmission to the conferee. In the disclosed arrangement the conference circuit can handle up to six simultaneous conferences each having up to five conferees. The circuitry is mainly concerned with the conversion of 8-bit non-linear codes into a 12-bit linear code, the binary addition of the 12-bit codes and the subsequent conversion of the summed code into an 8-bit code, and attention is directed to the Specification for a detailed description.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB4916872A GB1409610A (en) | 1972-10-25 | 1972-10-25 | Telephone exchanges |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
GB4916872A GB1409610A (en) | 1972-10-25 | 1972-10-25 | Telephone exchanges |
Publications (1)
Publication Number | Publication Date |
---|---|
GB1409610A true GB1409610A (en) | 1975-10-08 |
Family
ID=10451418
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB4916872A Expired GB1409610A (en) | 1972-10-25 | 1972-10-25 | Telephone exchanges |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB1409610A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4225956A (en) | 1978-08-28 | 1980-09-30 | E-Systems, Inc. | Multiplex conference bridge |
US4229814A (en) * | 1978-07-21 | 1980-10-21 | E-Systems, Inc. | Multiplex conference bridge |
FR2472318A1 (en) * | 1979-12-18 | 1981-06-26 | Telecommunications Sa | Telephone conference system - adds samples of selected subscriber channels and retransmits and distributes sum to subscribers as second order digital signal |
EP0358028A2 (en) * | 1988-09-07 | 1990-03-14 | Siemens Aktiengesellschaft | Device for a time division multiplexed digital telecommunication exchange |
EP0358981A2 (en) * | 1988-09-07 | 1990-03-21 | Siemens Aktiengesellschaft | Circuit for setting up conference connections in a digital time multiplexed telecommunication exchange |
-
1972
- 1972-10-25 GB GB4916872A patent/GB1409610A/en not_active Expired
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4229814A (en) * | 1978-07-21 | 1980-10-21 | E-Systems, Inc. | Multiplex conference bridge |
US4225956A (en) | 1978-08-28 | 1980-09-30 | E-Systems, Inc. | Multiplex conference bridge |
FR2472318A1 (en) * | 1979-12-18 | 1981-06-26 | Telecommunications Sa | Telephone conference system - adds samples of selected subscriber channels and retransmits and distributes sum to subscribers as second order digital signal |
EP0358028A2 (en) * | 1988-09-07 | 1990-03-14 | Siemens Aktiengesellschaft | Device for a time division multiplexed digital telecommunication exchange |
EP0358981A2 (en) * | 1988-09-07 | 1990-03-21 | Siemens Aktiengesellschaft | Circuit for setting up conference connections in a digital time multiplexed telecommunication exchange |
EP0358981A3 (en) * | 1988-09-07 | 1990-07-18 | Siemens Aktiengesellschaft | Circuit for setting up conference connections in a digital time multiplexed telecommunication exchange |
EP0358028A3 (en) * | 1988-09-07 | 1990-07-18 | Siemens Aktiengesellschaft | Device for a time division multiplexed digital telecommunication exchange |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
PS | Patent sealed | ||
746 | Register noted 'licences of right' (sect. 46/1977) | ||
732 | Registration of transactions, instruments or events in the register (sect. 32/1977) | ||
PCNP | Patent ceased through non-payment of renewal fee |