History of mobile phones
In the beginning, two-way radios (known as mobile rigs)
were used in vehicles such as taxicabs, police cruisers, ambulances,
and the like, but were not mobile phones because they were not normally
connected to the telephone network. Users could not dial phone numbers
from their mobile radios in their vehicles. 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 transportables or
"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 two-way radios. During the early 1940s, Motorola developed a backpacked two-way radio, the Walkie-Talkie
and later developed a large hand-held two-way radio for the US
military. This battery powered "Handie-Talkie" (HT) was about the size
of a man's forearm.
Early years
In December 1947, Douglas H. Ring and W. Rae Young, Bell Labs engineers, proposed hexagonal cells for mobile phones.[1]
Philip T. Porter, also of Bell Labs, proposed that the cell towers be
at the corners of the hexagons rather than the centers and have
directional antennas that would transmit/receive in 3 directions (see
picture at right) into 3 adjacent hexagon cells.[2] I [3]
The technology did not exist then and the frequencies had not yet been
allocated. Cellular technology was undeveloped until the 1960s, when
Richard H. Frenkiel and Joel S. Engel of Bell Labs developed the
electronics.
In Europe, radio telephony was first used on the first-class
passenger trains between Berlin and Hamburg in 1926. At the same time,
radio telephony was introduced on passenger airplanes for air traffic
security. Later radio telephony was introduced on a large scale in
German tanks during the Second World War.
After the war German police in the British zone of occupation first
used disused tank telephony equipment to run the first radio patrol
cars.[citation needed]
In all of these cases the service was confined to specialists that were
trained to use the equipment. In the early 1950s ships on the Rhine
were among the first to use radio telephony with an untrained end
customer as a user.
Recognizable mobile phones with direct dialing have existed at least since the 1950s. In the 1954 movie Sabrina, the businessman Linus Larrabee (played by Humphrey Bogart) makes a call from the phone in the back of his limousine.
The first fully automatic mobile phone system, called MTA (Mobile Telephone system A), was developed by Ericsson
and commercially released in Sweden in 1956. This was the first system
that didn't require any kind of manual control, but had the
disadvantage of a phone weight of 40 kg (90 lb). MTB, an upgraded version with transistors, weighing 9 kg (20 lb), was introduced in 1965 and used DTMF signaling. It had 150 customers in the beginning and 600 when it shut down in 1983.
In 1967, each mobile phone had to stay within the cell area serviced
by one base station throughout the phone call. This did not provide
continuity of automatic telephone service to mobile phones moving
through several cell areas. In 1970 Amos E. Joel, Jr., another Bell Labs engineer,[4]
invented an automatic "call handoff" system to allow mobile phones to
move through several cell areas during a single conversation without
loss of conversation.
In December 1971, AT&T submitted a proposal for cellular service to the Federal Communications Commission (FCC). After years of hearings, the FCC approved the proposal in 1982 for Advanced Mobile Phone Service (AMPS) and allocated frequencies in the 824-894 MHz band.[5] Analog AMPS was superseded by Digital AMPS in 1990.
One of the first truly successful public commercial mobile phone networks was the ARP network in Finland, launched in 1971. Posthumously, ARP is sometimes viewed as a zero generation (0G) cellular network, being slightly above previous proprietary and limited coverage networks.
Dr. Martin Cooper of Motorola, made the first US analogue mobile phone call on a larger prototype model in 1973.
On April 3, 1973, Motorola employee Dr. Martin Cooper placed a call to rival Joel Engel, head of research at AT&T's Bell Labs, while walking the streets of New York City talking on the first Motorola DynaTAC prototype in front of reporters. Motorola has a long history of making automotive radio, especially two-way radios for taxicabs and police cruisers.
In 1978, Bell Labs launched a trial of first commercial cellular network in Chicago using AMPS [1].
First generation
-
The first commercial launch of cellular telecoms was launched by NTT
in Tokyo Japan in 1979. In 1981 the NMT system was launched in Denmark,
Finland, Norway and Sweden. This was the first mobile phone technology
that allowed international use of the mobile phone or so-called
"roaming". The first handheld mobile phone in the US market was the Motorola DynaTAC 8000X, which received approval in 1983. 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 at first, all were designed for permanent
installation in vehicles (hence the term car phone). Soon, some of
these bulky units were converted for use as "transportable" phones the
size of a briefcase. Motorola introduced the first truly portable,
handheld phone. These systems (NMT, AMPS, TACS, RTMI, C-Netz, and Radiocom 2000) later became known as first generation (1G) mobile phones.
Second generation
-
Main articles: 2G, 2.5G, and 2.75G
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 pre-commercial digital cellular phone call was made in the United States in 1990, in 1991 the first GSM network (Radiolinja) opened in Finland.
2G phone systems were characterized by digital circuit switched
transmission and the introduction of advanced and fast phone to network
signaling. In general the frequencies used by 2G systems in Europe 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. In
America the IS-54 standard was deployed in the same band as AMPS and displaced some of the existing analog channels.
Coinciding with the introduction of 2G systems was a trend away from
the larger "brick" phones toward tiny 100–200g hand-held devices, which
soon became the norm. This change was possible through technological
improvements such as more advanced batteries and more energy-efficient
electronics, but also was largely related to the higher density of
cellular sites caused by increasing usage levels which decreased the
demand for high transmit powers to reach distant towers for customers
to be satisfied.
The second generation introduced a new variant to communication, as
SMS text messaging became possible, initially on GSM networks and
eventually on all digital networks. The first machine-generated SMS
message was sent in the UK in 1991. The first person-to-person SMS text
message was sent in Finland in 1993. Soon SMS became the communication
method of preference for the youth. Today in many advanced markets the
general public prefers sending text messages to placing voice calls.
2G also introduced the ability to consume media content on mobile
phones, when Radiolinja (now Elisa) in Finland introduced the
downloadable ringing tone as paid content. Finland was also the first
country where advertising appeared on the mobile phone when a free
daily news headline service on SMS text messaging was launched in 2000,
sponsored by advertising.
Third generation
-
Not long after the introduction of 2G networks, projects began to develop third generation (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 standardized in the
IMT-2000 standardization processing. This process did not standardize
on a technology, but rather on a set of requirements (2 Mbit/s maximum
data rate indoors, 384 kbit/s outdoors, for example). At that point,
the vision of a single unified worldwide standard broke down and
several different standards have been introduced.
The first pre-commercial trial network with 3G was launched by NTT
DoCoMo in Japan in the Tokyo region in May of 2001. NTT DoCoMo launched
the first commercial 3G network on October 1, 2001, using the WCDMA
technology. In 2002 the first 3G networks on the rival CDMA2000 1xEV-DO
technology were launched by SK Telecom and KTF in South Korea, and
Monet in the USA. Monet has since gone bankrupt. By the end of 2002,
the second WCDMA network was launched in Japan by Vodafone KK (now
Softbank). In March the first European launches of 3G were in Italy and
the UK by the Three/Hutchison group, on WCDMA. 2003 saw a further 8
commercial launches of 3G, six more on WCDMA and two more on the EV-DO
standard.
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. 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 3G system, but is so narrowly above these that any practical system would be sure to fall short.
By the end of 2007 there were 295 Million subscribers on 3G networks
worldwide, which reflected 9% of the total worldwide subscriber base.
About two thirds of these are on the WCDMA standard and one third on
the EV-DO standard. The 3G telecoms services generated over 120 Billion
dollars of revenues during 2007 and at many markets the majority of new
phones activated were 3G phones. In Japan and South Korea the market no
longer supplies phones of the second generation. Earlier in the decade
there were doubts about whether 3G might happen, and also whether 3G
might become a commercial success. By the end of 2007 it had become
clear that 3G was a reality and was clearly on the path to become a
profitable venture.
Live streaming of radio and television [2] to 3G handsets is one future direction for the industry, with companies from Real [3] and Disney [4] recently announcing services.
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