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Telecommunications In North Korea
Telecommunications in North Korea refers to the communication services available in North Korea. North Korea has not fully adopted mainstream Internet technology due to its isolationist policies. Telephone North Korea has an adequate telephone system, with 1.18 million fixed lines available in 2008. However, most phones are only installed for senior government officials. Someone wanting a phone installed must fill out a form indicating their rank, why they want a phone, and how they will pay for it. Most of these are installed in government offices, collective farms, and state-owned enterprises (SOEs), with only perhaps 10 percent controlled by individuals or households. By 1970 automatic switching facilities were in use in Pyongyang, Sinŭiju, Hamhŭng, and Hyesan. A few public telephone booths were beginning to appear in Pyongyang around 1990. In the mid-1990s, an automated exchange system based on an E-10A system produced by Alcatel joint-venture factories in China was in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
North Korea
North Korea, officially the Democratic People's Republic of Korea (DPRK), is a country in East Asia. It constitutes the northern half of the Korean Peninsula and shares borders with China and Russia to the north, at the Yalu (Amnok) and Tumen rivers, and South Korea to the south at the Korean Demilitarized Zone. North Korea's border with South Korea is a disputed border as both countries claim the entirety of the Korean Peninsula. The country's western border is formed by the Yellow Sea, while its eastern border is defined by the Sea of Japan. North Korea, like its southern counterpart, claims to be the legitimate government of the entire peninsula and adjacent islands. Pyongyang is the capital and largest city. In 1910, Korea was annexed by the Empire of Japan. In 1945, after the Japanese surrender at the end of World War II, Korea was divided into two zones along the 38th parallel, with the north occupied by the Soviet Union and the south occupied by the U ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Signature
A digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents. A valid digital signature, where the prerequisites are satisfied, gives a recipient very high confidence that the message was created by a known sender ( authenticity), and that the message was not altered in transit ( integrity). Digital signatures are a standard element of most cryptographic protocol suites, and are commonly used for software distribution, financial transactions, contract management software, and in other cases where it is important to detect forgery or tampering. Digital signatures are often used to implement electronic signatures, which includes any electronic data that carries the intent of a signature, but not all electronic signatures use digital signatures. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microwave Transmission
Microwave transmission is the transmission of information by electromagnetic waves with wavelengths in the microwave frequency range of 300MHz to 300GHz(1 m - 1 mm wavelength) of the electromagnetic spectrum. Microwave signals are normally limited to the line of sight, so long-distance transmission using these signals requires a series of repeaters forming a microwave relay network. It is possible to use microwave signals in over-the-horizon communications using tropospheric scatter, but such systems are expensive and generally used only in specialist roles. Although an experimental microwave telecommunication link across the English Channel was demonstrated in 1931, the development of radar in World War II provided the technology for practical exploitation of microwave communication. During the war, the British Army introduced the Wireless Set No. 10, which used microwave relays to multiplex eight telephone channels over long distances. A link across the English Channel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Frequency-division Multiplexing
In telecommunications, frequency-division multiplexing (FDM) is a technique by which the total bandwidth available in a communication medium is divided into a series of non-overlapping frequency bands, each of which is used to carry a separate signal. This allows a single transmission medium such as a microwave radio link, cable or optical fiber to be shared by multiple independent signals. Another use is to carry separate serial bits or segments of a higher rate signal in parallel. The most common example of frequency-division multiplexing is radio and television broadcasting, in which multiple radio signals at different frequencies pass through the air at the same time. Another example is cable television, in which many television channels are carried simultaneously on a single cable. FDM is also used by telephone systems to transmit multiple telephone calls through high capacity trunklines, communications satellites to transmit multiple channels of data on uplink and down ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intersputnik
The Intersputnik International Organization of Space Communications, commonly known as Intersputnik, is an international satellite communications services organization founded on 15 November 1971, in Moscow by the Soviet Union along with a group of eight formerly socialist states (Poland, Czechoslovakia, East Germany, Hungary, Romania, Bulgaria, Mongolia, and Cuba). The objective was and continues to be the development and common use of communications satellites. It was created as the Eastern Bloc's response to the Western Intelsat organization. As of 2008 the organization has 25 member states, among them the Federal Republic of Germany as the legal successor of the GDR. Intersputnik nowadays is a commercially aligned organization. It operates 12 satellites in orbit and 41 transponders. In June 1997 Intersputnik created the Lockheed Martin Intersputnik (LMI) joint venture together with Lockheed Martin, which built and operated the satellites of the same name. In September 2006, L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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