GB1362653A - Data network terminal unit - Google Patents

Data network terminal unit

Info

Publication number
GB1362653A
GB1362653A GB1101671A GB1101671A GB1362653A GB 1362653 A GB1362653 A GB 1362653A GB 1101671 A GB1101671 A GB 1101671A GB 1101671 A GB1101671 A GB 1101671A GB 1362653 A GB1362653 A GB 1362653A
Authority
GB
United Kingdom
Prior art keywords
bit
bits
data
signal
control
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
Application number
GB1101671A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
STC PLC
Original Assignee
Standard Telephone and Cables PLC
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Standard Telephone and Cables PLC filed Critical Standard Telephone and Cables PLC
Priority to GB1101671A priority Critical patent/GB1362653A/en
Priority to CH592272A priority patent/CH551724A/en
Publication of GB1362653A publication Critical patent/GB1362653A/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/05—Electric or magnetic storage of signals before transmitting or retransmitting for changing the transmission rate

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Synchronisation In Digital Transmission Systems (AREA)

Abstract

1362653 Speed changing in digital data transmission systems STANDARD TELEPHONES & CABLES Ltd 8 Feb 1972 [23 April 1971] 11016/71 Heading H4P To match the slower operating bit rate of a subscriber data terminal to the higher line transmission speed, a unit adds, or extracts according to the direction of transmission, M control bits for every N data bits transmitted, or received. In the arrangement described for every group of eight data bits a control bit is added after the fourth and eighth data bits, for synchronization or error correction purposes. Fig. 1 shows a circuit for receiving bits D from the line arriving at a bit rate A which are sampled by clocked bi-stable FF2 at n/n+m, i.e. 4/5, the rate A, i.e. with a sampling signal having a bit period 1<SP>1</SP>/ 5 th of the bit period of the arriving bits D, whereby no sampling takes place during the periods of the two control bits per group of eight, which control bits are sampled by bistable FF1 clocked by signal G. A synchronization clock F is compared with that one of the control bits acting as a synchronization bit to maintain the system in synchronism by adjusting the counter which generates clock signals F, G and C from the fundamental bit rate A and twice this frequency B. In the transmitting circuit Fig. 2, data from the terminal is sampled by bi-stable FF3 clocked by signal C at 4/5ths the transmission line bit rate A, to produce a data stream J, which is blocked by gate GG1 for the period of the synchronization control bit, i.e. overlapping the junction of bits 4 and 5 of signal J, which synchronization bit is then introduced by gate GG2 clocked by signal K, and for the other control bit period overlying data bit 8 of one group and data bit 1 of the next group, which second control bit is introduced by bi-stable FF4 and gate GG3 clocked by signal L. The data bits J and two control bits are combined at OR gate GG4 and then sampled for transmission to the output line by bi-stable FF5 clocked by the line bit rate signal A.
GB1101671A 1971-04-23 1971-04-23 Data network terminal unit Expired GB1362653A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB1101671A GB1362653A (en) 1971-04-23 1971-04-23 Data network terminal unit
CH592272A CH551724A (en) 1971-04-23 1972-04-21 ADAPTATION DEVICE BETWEEN A PARTICIPANT DATA EQUIPMENT AND A TRANSMISSION SYSTEM.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB1101671A GB1362653A (en) 1971-04-23 1971-04-23 Data network terminal unit

Publications (1)

Publication Number Publication Date
GB1362653A true GB1362653A (en) 1974-08-07

Family

ID=9978506

Family Applications (1)

Application Number Title Priority Date Filing Date
GB1101671A Expired GB1362653A (en) 1971-04-23 1971-04-23 Data network terminal unit

Country Status (2)

Country Link
CH (1) CH551724A (en)
GB (1) GB1362653A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1988007301A1 (en) * 1987-03-11 1988-09-22 Telefonaktiebolaget L M Ericsson Method and apparatus for transmitting a synchronous data signal on a transmission medium on which the transmission rate is greater than the data signal bit rate
EP0993158A1 (en) * 1998-10-07 2000-04-12 Siemens Aktiengesellschaft Apparatus and method for data rate conversion

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1988007301A1 (en) * 1987-03-11 1988-09-22 Telefonaktiebolaget L M Ericsson Method and apparatus for transmitting a synchronous data signal on a transmission medium on which the transmission rate is greater than the data signal bit rate
EP0993158A1 (en) * 1998-10-07 2000-04-12 Siemens Aktiengesellschaft Apparatus and method for data rate conversion

Also Published As

Publication number Publication date
CH551724A (en) 1974-07-15

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Legal Events

Date Code Title Description
PS Patent sealed
435 Patent endorsed 'licences of right' on the date specified (sect. 35/1949)
PCNP Patent ceased through non-payment of renewal fee