20 September (Ethiopia ) within release 6rd World Telecommunications Exhibition, Geneva goes into circulation Stamp Dish antenna face value 45 Ethiopian cent
Stamp Dish antenna in catalogues | |
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Stamp Number: | Sn:ET 944 |
Stamp is square format.
Data entry completed
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Stamp Dish antenna in digits | |
Country: | Ethiopia |
Date: | 1979-09-20 |
Print: | Photogravure |
Perforation: | 11½ |
Emission: | Commemorative |
Format: | Stamp |
Face Value: | 45 Ethiopian cent |
Stamp Dish antenna it reflects the thematic directions:
Telecommunication, often used in its plural form or abbreviated as telecom, is the transmission of information with an immediacy comparable to face-to-face communication. As such, slow communications technologies like postal mail and pneumatic tubes are excluded from the definition. Many transmission media have been used for telecommunications throughout history, from smoke signals, beacons, semaphore telegraphs, signal flags, and optical heliographs to wires and empty space made to carry electromagnetic signals. These paths of transmission may be divided into communication channels for multiplexing, allowing for a single medium to transmit several concurrent communication sessions. Several methods of long-distance communication before the modern era used sounds like coded drumbeats, the blowing of horns, and whistles. Long-distance technologies invented during the 20th and 21st centuries generally use electric power, and include the telegraph, telephone, television, and radio.