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Mobile Radio Telephone
Mobile radio telephone systems were telephone systems of a wireless type that preceded the modern cellular mobile form of telephony technology. Since they were the predecessors of the first generation of cellular telephones, these systems are sometimes retroactively referred to as pre-cellular (or sometimes zero generation, that is, 0G) systems. Technologies used in pre-cellular systems included the Push to Talk (PTT or manual), Mobile Telephone Service (MTS), Improved Mobile Telephone Service (IMTS), and Advanced Mobile Telephone System (AMTS) systems. These early mobile telephone systems can be distinguished from earlier closed radiotelephone systems in that they were available as a commercial service that was part of the public switched telephone network, with their own telephone numbers, rather than part of a closed network such as a police radio or taxi dispatching system. These mobile telephones were usually mounted in cars or trucks (thus called '' car phones''), alth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bell System
The Bell System was a system of telecommunication companies, led by the Bell Telephone Company and later by the American Telephone and Telegraph Company (AT&T), that dominated the telephone services industry in North America for over one hundred years from its creation in 1877 until its antitrust breakup in 1983. The system of companies was often colloquially called Ma Bell (as in "Mother Bell"), as it held a vertical monopoly over telecommunication products and services in most areas of the United States and Canada. At the time of the breakup of the Bell System in the early 1980s, it had assets of $150 billion (equivalent to $ billion in ) and employed over one million people. Ever since the 1910s, American antitrust regulators had been observing and accusing the Bell System of abusing its monopoly power, and had brought legal action multiple times over the decades, until in 1974 the Antitrust Division of the U.S. Department of Justice brought a lawsuit against B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
AMR Radiotelephone Network (Czechoslovakia)
The very first analog mobile radio telephone in Czechoslovakia (and in the whole Eastern Bloc) was AMR (sometimes AMRAD), in Czech Automatizovaný městský radiotelefon (''Automated Municipal Radiotelephone''). The system was developed by company Tesla in Pardubice. Since 1978 it was tested in experimental mode and in 1983 it switched into full mode. At the time it was used mainly for communication between distant employees (typically in telecommunication industry). After 1989 commercial use was allowed and the network stayed until 1999 when it was stopped. The network was owned and operated by state telecom company "SPT Telecom" (later Český Telecom, then Telefónica O2 Czech Republic). Technical features * The complete network has 63 base stations and capacity for 9,999 users (4 numbers were used for identification). * Reach of base station was 15 – 25 km, the radiophones were also able to communicate directly with one another. * Three frequency bands were used: 162/1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finland
Finland ( fi, Suomi ; sv, Finland ), officially the Republic of Finland (; ), is a Nordic country in Northern Europe. It shares land borders with Sweden to the northwest, Norway to the north, and Russia to the east, with the Gulf of Bothnia to the west and the Gulf of Finland across Estonia to the south. Finland covers an area of with a population of 5.6 million. Helsinki is the capital and largest city, forming a larger metropolitan area with the neighbouring cities of Espoo, Kauniainen, and Vantaa. The vast majority of the population are ethnic Finns. Finnish, alongside Swedish, are the official languages. Swedish is the native language of 5.2% of the population. Finland's climate varies from humid continental in the south to the boreal in the north. The land cover is primarily a boreal forest biome, with more than 180,000 recorded lakes. Finland was first inhabited around 9000 BC after the Last Glacial Period. The Stone Age introduced several different ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
