Essay about pomegranate

 In this report, we will have a comprehensive look at fiber optics and its applications. At present, optical fiber due to the appropriate transmission characteristics (high bandwidth, low drop, etc.) has found an important place in telecommunication transmission networks and it is predicted that in the future the most important and best transmission environment, for use in long distances and Be close. The purpose of this report is to review and introduce this transmission environment in terms of building aspects and advantages and disadvantages.

1 -1- A window to the world of the telegraph The telegraph was originally invented by the American Morse in 1832, 1212 AD. This was the first sentence to be transmitted by telegram. 1-2- Invention of telephone On the afternoon of June 2, 1875, Alexander Graham Bell of England, with the help of his friend Watson, invented the telephone, and in January 1876, the telephone was put into operation.

Fourteen years later, in 1890, Stroger built the automatic telephone system. 1-3- Telecommunications in Iran and Tehran Telegraph The news of the new invention (telegraph) by Aga Khan Nouri, the then Prime Minister of Iran reached Nasser al-Din Shah and attracted his attention and it was decided that this device would be used in Iran. In March of 1236, 14 years after the transmission of the first telegram message of Samuel Morse, the telegraph system under the supervision of Ali Mirza Etezad Al-Saltanah (affiliated to the Qajar court) and with the collaboration of Rezaghili Khanullah Bashi Tabarestani (then head of the Academy of Arts) by "Karshsh" ( One of the art teachers) was successfully tested and the following sentence was transmitted: Immediately, karsim drawing began between Ark Palace and Lalehzar Garden in Tehran, and this telegraph line also started operating in 1237 AD. The first relatively long telegraph line in Iran, 300 km away, was established in July 1238 AD between Tehran and Chaman Soltanieh (Nasser al-Din Shah summer camp near Zanjan) and started operating. Tehran-Tabriz telegraph connection was established in 1240 and the following year the Tehran-Gilan telegraph line started operating. For the first time, Iran's telegraph connection with Russia was established through the connection of the Tehran-Tabriz line with the Russian telegraph network in 1342, and the Russian emperor and the king of Iran exchanged congratulatory telegrams. In 1253, after separating from the Ministry of Science, the Telegraph Office became the Ministry of Telegraphs. Phone In 1265 AD, coinciding with 1886 AD, for the first time in Iran, a series of telephone wires between Tehran and Prince Abdolazim with a length of 8.7 km was laid by the Belgian Boatal, which had the privilege of the Ray railway, but in fact the second stage of telecommunication technology. In Tehran, since 1268 AD, that is, 13 years after the invention of the telephone, the establishment between the two smoky car stations of Tehran and the city of Rey began. After that, a telephone connection was established between Kamraniyeh (Shemiran) and the building of the Ministry of War in Tehran, and then between the summer residence of Shah Qajar (former Sultanabad) and the Royal Mansion of Tehran. The Ministry of Telegraph was merged with the Ministry of Post in 1287 AD and was renamed the Ministry of Post and Telegraph. In 1302, a contract was signed with Siemens and Halske for the construction of underground telephone lines, and three years later, in October 1305, a new automatic telephone was put into operation on 2300 cable lines in the center of Ekbatan.