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Home > Mobile phone


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:Cellular links here. For the 2004 movie, Cellular, see Cellular (movie).


A mobile phone is a mobile device which acts as a normal

telephone whilst being able to move over a wide area. Mobile

phones allow connections to be made to the

telephone network, normally by

directly dialling the other party's number on an inbuilt keypad. Most current mobile phones use a combination of radio wave

transmission and conventional telephone circuit switching, though packet switching is already in use for some parts of the mobile phone network, especially for services such as push to talk.

There are also specialist communication systems related to, but distinct from mobile phones, such as satellite phones and Professional Mobile Radio.

1 History


Mobile rigs, such as ham radio gear installed in automobiles were the predecessor of mobile phones, along with taxicab radios, two way radios in police cruisers, and the like. A large community of mobile radio users, known as the mobileers, popularized the technology that would eventually give way to the mobile phone. Originally, mobile phones were permanently installed in vehicles, but later versions such as the so-called "bag phones" were equipped with a cigarette lighter plug so that they could also be carried, and thus could be used as either mobile or as portable phones.

What was possibly the first real mobile phone, in the sense that it was connected to the telephone network, was tested by the Swedish police in 1946Events January January 4 Theodore Schurch becomes the last person to be executed for offences committed under the Treachery Act of 1940 January 7 Allied recognize Austrian republic with 1937 borders the country is divided into four occupation zones Januar, for use in police cruisers. A half dozen calls could be made before the police car's battery ran out. Radiophones began to be publicly available, in the US, at the end of the 1940s[1] though the distinction between such phones and a two way radio becomes blurry since special systems are required to "patch" into the phone networkA wide variety of systems of interconnected components are called networks . Specific examples include: television networks transport networks, roads, railroads, shipping routes and airlines, pipelines (gas, petroleum, water, sewage), electric circuits a with the assistance of human operators. Recognisable mobile phones with direct dialling have existed at least since the 1950sCenturies: 19th century 20th century 21st century Decades: 1900s 1910s 1920s 1930s 1940s 1950s 1960s 1970s 1980s 1990s 2000s Years: 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 Events and trends Technology United States tests the first fusion bomb.

Modern mobile telephony is often considered to have started on April 3April 3 is the 93rd day of the year (94th in leap years) in the Gregorian calendar, with 272 days remaining. Events 1559 The Treaty of the Peace of Cateau-Cambresis is signed. 1860 The first successful Pony Express run from Saint Joseph, Missouri to Sacra, 1973Events January events January 1 United Kingdom, Ireland, and Denmark enter the European Economic Community now known as the European Union January 3 Columbia Broadcasting System (CBS) sells the New York Yankees for $10 million to a 12-person syndicate led, when Martin Cooper – then an employee of MotorolaMotorola started as Galvin Manufacturing Corporation in 1928. The name of the company was changed to Motorola in 1947, but the word had been used as a trademark since the 1930s. The company is based in Schaumburg, Illinois, a Chicago suburb. Founder Paul – placed the first call to the company's rival AT&TAT&T formerly an abbreviation for American Telephone and Telegraph Corporation is an American telecommunications company, publicly listed on the New York Stock Exchange under the ticker symbol T . AT&T provides voice, video, data, and Internet telecommuni's Bell LabsBell Telephone Laboratories or Bell Labs was originally the research and development arm of the United States Bell System, and was the premier corporate facility of its type, developing a range of revolutionary technologies from telephone switches to spec, while walking the streets of New York City. Motorola (Motor-ola) has a long history of making automotive radio, especially two-way radios for taxicabs and police cruisers.

Mobile phones began to proliferate through the 1980s with the introduction of "cellular" phones based on cellular networks with multiple base stations located relatively close to each other, and protocols for the automated "handover" between two cells when a phone moved from one cell to the other. At this time analog transmission was in use in all systems. Mobile phones were somewhat larger than current ones, and many were designed for permanent installation in cars (hence the term car phone), or as "transportable" phones the size of a briefcase. These systems ( NMT, AMPS, TACS) later became known as first generation mobile phones.

In September 1981 the first cell phone network with automatic roaming was started in Saudi Arabia; it was an NMT system. One month later the Nordic countries started an NMT network with automatic roaming between countries.

In the 1990s, second generation ( 2G) mobile phone systems such as GSM, IS-136 ("TDMA"), iDEN and IS-95 ("CDMA") began to be introduced. The first digital cellular phone call was made in the United States in 1990, in 1991 the first GSM network opened in Europe. 2G phone systems characterised by digital circuit switched transmission and the introduction of advanced and fast phone to network signalling. In general the frequencies used by 2G systems were higher though with some overlap, for example the 900 MHz frequency range was used for both 1G and 2G systems in Europe and so such 1G systems were rapidly closed down to make space for 2G systems.

Coinciding with the introduction of 2G systems were trends which meant that the larger "bricks" disappeared and tiny 100–200g hand-held devices became the norm. These trends included technology improvements such as better battery technologies and lower power electronics, but also are largely related to the higher density of cellular sites caused by increasing usage levels.

In most of Europe, wealthy parts of Asia, and Australia, mobile phones are now virtually universal, with the majority of the adult, teenage, and even child population owning one. They are less common in the United States — while widely available, market penetration is lower than elsewhere in the developed world (around 66 percent of the U.S. population as of 2003). Reasons advanced for this include incomplete coverage, relatively high minimum monthly service charges (around $30), and the availability of relatively low-cost fixed-line networks (around $30 for unlimited local calling). One consequence of this disparity in market penetration is a lag in the changing perception of the social status attached to mobile phone ownership. During the 1980's and 90's possessing a mobile phone was generally seen as an indicator of upwardly mobility, which is still just barely the case in North America, whereas particularly in Britain the mobile has become so ubiqitous and heavily used by the teenage population that it is looked upon as declasse.

Not long after the introduction of 2G networks, projects began to develop 3G systems. Inevitably there were many different standards with different contenders pushing their own technologies. Quite differently from 2G systems, however, the meaning of 3G has been standardised in the IMT-2000 standardisation process. This process did not standardise on a technology, but rather on a set of requirements (2Mb/s maximum data rate indoors, 384Kb/s outdoors, for example). At that point, the vision of a single unified worldwide standard broke down and several different standards have been introduced.

During the development of 3G systems, 2.5G systems such as CDMA2000 1x and GPRS were developed as extensions to existing 2G networks. These provide some of the features of 3G without fulfilling the promised high data rates or full range of multimedia services. E.g. CDMA2000-1X delivers theoretical maximum data speeds of up to 307 kbit/s. Just beyond these is the EDGE system which in theory covers the requirements for a 3G system, but is so narrowly above these that any practical system would be sure to fall short.

At the beginning of the 21st century, 3G mobile phone systems such as UMTS and CDMA2000 1xEV-DO have now begun to be publicly available. The final success of these systems is still to be determined.



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