tailieunhanh - Giáo trình tiếng anh điện tử viễn thông - digital telephone exchanges p3

Classification a. Means of transmission b. Service c. Circuit switched network d. Method of signalling e. Electronic system f. Light sources g. Remote part of an exchange Characteristics /Function A. It provides a means of asynchronous data transmission. B. It uses one pair for performing all signalling functions of one route. C. It involves the sampling and coding of analogue signals. D. They enable PCM transmission to be used further out in the local network. | Unit 7. Computer Communications Classification light sources Characteristics Function They produce light of a closely defined wavelength. - Lasers are light sources producing light of a closely defined wavelength. Practice . Use the table below to put together the definitions. Example 1. f E Name Classification Characteristics Function 1. Lasers 2. PCM 3. Electronic mail 4. Telefax 5. CCS 6. SPC 7. Remote concentrators 8. Nordic Public Data network a. Means of transmission b. Service c. Circuit switched network d. Method of signalling e. Electronic system f. Light sources g. Remote part of an exchange A. It provides a means of asynchronous data transmission. B. It uses one pair for performing all signalling functions of one route. C. It involves the sampling and coding of analogue signals. D. They enable PCM transmission to be used further out in the local network. E. They produce light of a closely defined wavelength. F. It uses data processing and computer techniques for switching. G. It enables videotex subscribers to send messages directly and instantaneously to one another. H. It provides for the transmission and reproduction of still pictures and printed matters. B. Analyse the following definitions. Identify whether the underlined parts are Term T Group G or Characteristics C . Example A computer is a machine with an intricate network of electronic circuits that Term T Group G Characteristics C operate switches or magnetize tiny metal cores. 1. Silicon is a nonmetallic element with semiconductor characteristics. 2. An abacus is a bead frame in which the beads are moved form left to right. 3. Input is the information presented to the computer. 4. The term computer includes those parts of hardware in which calculations and other data manipulations are performed and the high-speed interval memory in which data and calculations are stored during actual executions of programs. 5. A system is a good mixture of integrated parts working together to form a .