This history focuses on communication devices which connect
wirelessly to the public switched telephone network. The transmission of speech
by radio has a long and varied history going back to Reginald Fessenden's
invention and shore-to-ship demonstration of radio telephony. The first mobile
telephones were barely portable compared to today's compact hand-held devices.
Along with the process of developing more portable technology, drastic changes
have taken place in the networking of wireless communication and the prevalence
of its use.
Predecessors
Before the devices that are now referred to as mobile phones
existed, there were some precursors. In 1908 a Professor Albert Jahnke and the
Oakland Transcontinental Aerial Telephone and Power Company claimed to have
developed a wireless telephone. They were accused of fraud and the charge was
then dropped, but they do not seem to have proceeded with production. Beginning
in 1918 the German railroad system tested wireless telephony on military trains
between Berlin and Zossen. In 1924, public trials started with telephone
connection on trains between Berlin and Hamburg. In 1925, the company
Zugtelephonie A. G. was founded to supply train telephony equipment and in 1926
telephone service in trains of the Deutsche Reichsbahn and the German mail
service on the route between Hamburg and Berlin was approved and offered to 1st
class travelers.
Karl Arnold drawing
of public use of mobile telephones
In 1907, the English caricaturist Lewis Baumer published a
cartoon in Punch magazine entitled "Predictions for 1907" in which he
showed a man and a woman in London's Hyde Park each separately engaged in
gambling and dating on wireless telephony equipment. Then in 1926 the artist
Karl Arnold created a visionary cartoon about the use of mobile phones in the
street, in the picture "wireless telephony", published in the German
satirical magazine Simplicissimus.
The portrayal of a utopia of mobile phone in literature
dates back to the year 1931. It is found in Erich Kästner's children's book the
35th of May, or Conrad's Ride to the South Seas:
“A gentleman who rode along the sidewalk in front of them,
suddenly stepped off the conveyor belt, pulled a phone from his coat pocket,
spoke a number into it and shouted: "Gertrude, listen, I'll be an hour
late for lunch because I want to go to the laboratory. Goodbye,
sweetheart!" Then he put his pocket phone away again, stepped back on the
conveyor belt, and started reading a book... ”
—Erich Kästner
The Second World War made military use of radio telephone
links. Hand-held radio transceivers have been available since the 1940s. Mobile
telephones for automobiles became available from some telephone companies in
the 1940s. Early devices were bulky and consumed high power and the network
supported only a few simultaneous conversations. Modern cellular networks allow
automatic and pervasive use of mobile phones for voice and data communications.
In the United States, engineers from Bell Labs began work on
a system to allow mobile users to place and receive telephone calls from
automobiles, leading to the inauguration of mobile service on 17 June 1946 in
St. Louis, Missouri. Shortly after, AT&T offered Mobile Telephone Service.
A wide range of mostly incompatible mobile telephone services offered limited
coverage area and only a few available channels in urban areas. The
introduction of cellular technology, which allowed re-use of frequencies many
times in small adjacent areas covered by relatively low powered transmitters,
made widespread adoption of mobile telephones economically feasible.
One of the earliest fictional descriptions of a mobile phone
can be found in the 1948 science fiction novel Space Cadet by Robert Heinlein.
The protagonist, who has just traveled to Colorado from his home in Des Moines,
receives a call from his father on a pocket telephone. Before going to space he
decides to ship the telephone home “since it was limited by its short range to
the neighborhood of an earth-side [i.e. terrestrial] relay office.” Ten years
later, an essay by Arthur C. Clarke envisioned a "personal transceiver, so
small and compact that every man carries one." He wrote: "the time
will come when we will be able to call a person anywhere on Earth merely by
dialing a number." Such a device would also, in Clarke's vision, include means
for global positioning so that "no one need ever again be lost."
Later, in Profiles of the Future, he predicted the advent of such a device taking
place in the mid-1980s. US TV series Get Smart (1965-1970) depicted spy gadgets
with mobile telephones concealed in random objects, including shoes.
In the USSR, Leonid Kupriyanovich, an engineer from Moscow,
in 1957-1961 developed and presented a number of experimental models of
handheld mobile phones. The weight of one model, presented in 1961, was only 70
g and could fit on a palm. However in the USSR the decision at first to develop
the system of the automobile "Altai" phone was made.
In 1965, Bulgarian company "Radioelektronika"
presented on the Inforga-65 international exhibition in Moscow the mobile
automatic phone combined with a base station. Solutions of this phone were
based on a system developed by Leonid Kupriyanovich. One base station,
connected to one telephone wire line, could serve up to 15 customers.
The advances in mobile telephony can be traced in successive
generations from the early "0G" services like MTS and its successor
Improved Mobile Telephone Service, to first generation (1G) analog cellular
network, second generation (2G) digital cellular networks, third generation
(3G) broadband data services to the current state of the art, fourth generation
(4G) native-IP networks.
Early services
MTS
In 1949 AT&T commercialized Mobile Telephone Service.
From its start in St. Louis in 1946, AT&T then introduced Mobile Telephone
Service to one hundred towns and highway corridors by 1948. Mobile Telephone
Service was a rarity with only 5,000 customers placing about 30 000 calls each
week. Calls were set up manually by an operator and the user had to depress a
button on the handset to talk and release the button to listen. The call
subscriber equipment weighed about 36 kg.
Subscriber growth and revenue generation were hampered by
the constraints of the technology. Because only three radio channels were
available, only three customers in any given city could make mobile telephone
calls at one time. Mobile Telephone Service was expensive, costing 15 USD per
month, plus 0.30 to 0.40 USD per local call, equivalent to about 176 USD per
month and 3.50 to 4.75 per call in 2012 USD.
In the UK there was also a vehicle based system called
"Post Office Radiophone Service" it was launched around the city of
Manchester in 1959, and although it required callers to speak to an operator,
it was possible to be put through to any subscriber in Great Britain. The
service was extended to London in 1965 and other major cities in 1972.
IMTS
AT&T introduced the first major improvement to mobile
telephony in 1965, giving the improved service the obvious name of Improved
Mobile Telephone Service. IMTS used additional radio channels, allowing more
simultaneous calls in a given geographic area, introduced customer dialing,
eliminating manual call setup by an operator, and reduced the size and weight of
the subscriber equipment.
Despite the capacity improvement offered by IMTS, demand outstripped
capacity. In agreement with state regulatory agencies, AT&T limited the
service to just 40,000 customers system wide. In New York City, for example,
2,000 customers shared just 12 radio channels and typically had to wait 30
minutes to place a call.
Radio Common Carrier
A mobile radio
telephone
Radio Common Carrier or RCC was a service introduced in the
1960s by independent telephone companies to compete against AT&T's IMTS.
RCC systems used paired UHF 454/459 MHz and VHF 152/158 MHz frequencies near
those used by IMTS. RCC based services were provided until the 1980s when
cellular AMPS systems made RCC equipment obsolete.
Some RCC systems were designed to allow customers of
adjacent carriers to use their facilities, but equipment used by RCCs did not
allow the equivalent of modern "roaming" because technical standards
were not uniform. For example, the phone of an Omaha, Nebraska–based RCC
service would not be likely to work in Phoenix, Arizona. Roaming was not
encouraged, in part, because there was no centralized industry billing database
for RCCs. Signaling formats were not standardized. For example, some systems
used two-tone sequential paging to alert a mobile of an incoming call. Other
systems used DTMF. Some used Se-code 2805, which transmitted an interrupted
2805 Hz tone (similar to IMTS signaling) to alert mobiles of an offered call.
Some radio equipment used with RCC systems was half-duplex, push-to-talk LOMO
equipment such as Motorola hand-held or RCA 700-series conventional two-way
radios. Other vehicular equipment had telephone handsets and rotary dials or
pushbutton pads, and operated full duplex like a conventional wired telephone.
A few users had full-duplex briefcase telephones (radically advanced for their
day)
At the end of RCC's existence, industry associations were
working on a technical standard that would have allowed roaming, and some
mobile users had multiple decoders to enable operation with more than one of
the common signaling formats (600/1500, 2805, and Reach). Manual operation was
often a fallback for RCC roamers.
Other services
In 1969 Penn Central Railroad equipped commuter trains along
the 360 km New York-Washington route with special pay phones that allowed
passengers to place telephone calls while the train was moving. The system
re-used six frequencies in the 450 MHz band in nine sites.
European mobile radio
networks
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In Europe, several mutually incompatible mobile radio
services were developed. West Germany had a network called A-Netz launched in
1952 as the country's first public commercial mobile phone network. In 1972
this was displaced by B-Netz which connected calls automatically. In 1966
Norway had a system called OLT which was manually controlled.
Cellular concepts
A multi-directional, cellular network antenna array
("cell tower")
In December 1947, Douglas H. Ring and W. Rae Young, Bell
Labs engineers, proposed hexagonal cells for mobile phones in vehicles. At this
stage, the technology to implement these ideas did not exist, nor had the
frequencies been allocated. Two decades would pass before Richard H. Frenkiel,
Joel S. Engel and Philip T. Porter of Bell Labs expanded the early proposals
into a much more detailed system plan. It was Porter who first proposed that
the cell towers use the now-familiar directional antennas to reduce
interference and increase channel reuse Porter also
invented the dial-then-send method used by all cell phones to reduce wasted
channel time.
In all these early examples, a mobile phone had to stay
within the coverage area serviced by one base station throughout the phone
call, i.e. there was no continuity of service as the phones moved through
several cell areas. The concepts of frequency reuse and handoff, as well as a
number of other concepts that formed the basis of modern cell phone technology,
were described in the late 1960s, in papers by Frenkiel and Porter. In 1970
Amos E. Joel, Jr., a Bell Labs engineer invented a "three-sided trunk
circuit" to aid in the "call handoff" process from one cell to
another. His patent contained an early description of the Bell Labs cellular
concept, but as switching systems became faster, such a circuit became
unnecessary and was never implemented in a system.
A cellular telephone switching plan was described by Fluhr
and Nussbaum in 1973, and a cellular telephone data signaling system was described
in 1977 by Hachenburg et al.
Emergence of
automated services
The first fully automated mobile phone system for vehicles
was launched in Sweden in 1956. Named MTA (Mobil telephony system A), it
allowed calls to be made and received in the car using a rotary dial. The car
phone could also be paged. Calls from the car were direct dial, whereas
incoming calls required an operator to locate the nearest base station to the
car. It was developed by Sture Laurén and other engineers at Televerket network
operator. Ericsson provided the switchboard while Svenska Radio Aktiebolaget
(SRA) and Marconi provided the telephones and base station equipment. MTA
phones consisted of vacuum tubes and relays, and weighed 40 kg. In 1962, an
upgraded version called Mobile System B (MTB) was introduced. This was a
push-button telephone, and used transistors and DTMF signaling to improve its
operational reliability. In 1971 the MTD version was launched, opening for
several different brands of equipment and gaining commercial success. The
network remained open until 1983 and still had 600 customers when it closed.
In 1958 development began on a similar system for motorists
in the USSR. The "Altay" national civil mobile phone service was
based on Soviet MRT-1327 standard. The main developers of the Altay system were
the Voronezh Science Research Institute of Communications (VNIIS) and the State
Specialized Project Institute (GSPI). In 1963 the service started in Moscow,
and by 1970 was deployed in 30 cities across the USSR. Versions of the Altay
system are still in use today as a trucking system in some parts of Russia.
In 1959 a private telephone company located in Brewster,
Kansas, USA, the S&T Telephone Company, (still in business today) with the
use of Motorola Radio Telephone equipment and a private tower facility, offered
to the public mobile telephone services in that local area of NW Kansas. This
system was a direct dial up service through their local switchboard, and was
installed in many private vehicles including grain combines, trucks, and
automobiles. For some as yet unknown reason, the system, after being placed
online and operated for a very brief time period, was shut down. The management
of the company was immediately changed, and the fully operable system and
related equipment was immediately dismantled in early 1960, not to be seen
again.
In 1966, Bulgaria presented the pocket mobile automatic
phone RAT-0,5 combined with a base station RATZ-10 (RATC-10) on
Interorgtechnika-66 international exhibition. One base station, connected to
one telephone wire line, could serve up to six customers ("Radio"
magazine, 2, 1967; "Novosti dnya" newsreel, 37, 1966).
One of the first 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.
Handheld mobile phone
Martin Cooper photographed in 2007 with his 1973 handheld
mobile phone prototype
Prior to 1973, mobile telephony was limited to phones
installed in cars and other vehicles. Motorola was the first company to produce
a handheld mobile phone. On 3 April 1973 when Martin Cooper, a Motorola
researcher and executive, made the first mobile telephone call from handheld
subscriber equipment, placing a call to Dr. Joel S. Engel of Bell Labs. The
prototype handheld phone used by Dr. Cooper weighed 1.1 kg and measured 23 cm
long, 13 cm deep and 4.45 cm wide. The prototype offered a talk time of just 30
minutes and took 10 hours to re-charge.
John F. Mitchell, Motorola's chief of portable communication
products and Cooper's boss in 1973, played a key role in advancing the
development of handheld mobile telephone equipment. Mitchell successfully
pushed Motorola to develop wireless communication products that would be small
enough to use anywhere and participated in the design of the cellular phone.
Analog cellular
networks – 1G
The first automatic analog cellular systems deployed were
NTT's system first used in Tokyo in 1979, later spreading to the whole of
Japan, and NMT in the Nordic countries in 1981.
The first analog cellular system widely deployed in North
America was the Advanced Mobile Phone System (AMPS). It was commercially
introduced in the Americas in October 1983, Israel in 1986, and Australia in
1987. AMPS were a pioneering technology that helped drive mass market usage of
cellular technology, but it had several serious issues by modern standards. It
was unencrypted and easily vulnerable to eavesdropping via a scanner; it was
susceptible to cell phone "cloning;" and it used a Frequency-division
multiple access (FDMA) scheme and required significant amounts of wireless
spectrum to support.
On 6 March 1983, the DynaTAC mobile phone launched on the
first US 1G network by Ameritech. It cost $100m to develop, and took over a
decade to reach the market. The phone had a talk time of just half an hour and
took ten hours to charge. Consumer demand was strong despite the battery life,
weight, and low talk time, and waiting lists were in the thousands.
Many of the iconic early commercial cell phones such as the
Motorola DynaTAC Analog AMPS were eventually superseded by Digital AMPS
(D-AMPS) in 1990, and AMPS service was shut down by most North American
carriers by 2008.
Digital cellular
networks – 2G
Two 1991 GSM mobile phones with several AC adapters
In the 1990s, the 'second generation' mobile phone systems
emerged. Two systems competed for supremacy in the global market: the European
developed GSM standard and the U.S. developed CDMA standard. These differed
from the previous generation by using digital instead of analog transmission,
and also fast out-of-band phone-to-network signaling. The rise in mobile phone
usage as a result of 2G was explosive and this era also saw the advent of
prepaid mobile phones.
In 1991 the first GSM network (Radiolinja) launched in
Finland. In general the frequencies used by 2G systems in Europe were higher
than those in America, though with some overlap. For example, the 900 MHz
frequency range was used for both 1G and 2G systems in Europe, so the 1G
systems were rapidly closed down to make space for the 2G systems. In America
the IS-54 standard was deployed in the same band as AMPS and displaced some of
the existing analog channels.
In 1993, IBM Simon was introduced. This was possibly the
world's first smartphone. It was a mobile phone, pager, fax machine, and PDA
all rolled into one. It included a calendar, address book, clock, calculator,
notepad, email, and a touchscreen with a QWERTY keyboard. The IBM Simon had a
stylus you used to tap the touch screen with. It featured predictive typing
that would guess the next characters as you tapped. It had applications, or at
least a way to deliver more features by plugging a PCMCIA 1.8 MB memory card
into the phone. Coinciding with the introduction of 2G systems was a trend away
from the larger "brick" phones toward tiny 100 – 200 gram hand-held
devices. This change was possible not only through technological improvements
such as more advanced batteries and more energy-efficient electronics, but also
because of the higher density of cell sites to accommodate increasing usage.
The latter meant that the average distance transmission from phone to the base
station shortened, leading to increased battery life while on the move.
Personal Handy-phone
System mobiles and modems used in Japan around 1997–2003
The second generation introduced a new variant of
communication called SMS or text messaging. It was initially available only on
GSM networks but spread eventually on all digital networks. The first
machine-generated SMS message was sent in the UK on 3 December 1992 followed in
1993 by the first person-to-person SMS sent in Finland. The advent of prepaid
services in the late 1990s soon made SMS the communication method of choice
among the young, a trend which spread across all ages.
2G also introduced the ability to access media content on
mobile phones. In 1998 the first downloadable content sold to mobile phones was
the ring tone, launched by Finland's Radiolinja (now Elisa). Advertising on the
mobile phone first appeared in Finland when a free daily SMS news headline
service was launched in 2000, sponsored by advertising.
Mobile payments were trialed in 1998 in Finland and Sweden
where a mobile phone was used to pay for a Coca Cola vending machine and car
parking. Commercial launches followed in 1999 in Norway. The first commercial
payment system to mimic banks and credit cards was launched in the Philippines
in 1999 simultaneously by mobile operators Globe and Smart.
The first full internet service on mobile phones was
introduced by NTT DoCoMo in Japan in 1999.
Mobile broadband data
- 3G
As the use of 2G phones became more widespread and people
began to utilize mobile phones in their daily lives, it became clear that
demand for data (such as access to browse the internet) was growing. Further,
experience from fixed broadband services showed there would also be an ever
increasing demand for greater data speeds. The 2G technology was nowhere near
up to the job, so the industry began to work on the next generation of
technology known as 3G. The main technological difference that distinguishes 3G
technology from 2G technology is the use of packet switching rather than
circuit switching for data transmission. In addition, the standardization
process focused on requirements more than technology (2 Mbit/s maximum data
rate indoors, 384 kbit/s outdoors, for example).
Inevitably this led to many competing standards with
different contenders pushing their own technologies, and the vision of a single
unified worldwide standard looked far from reality. The standard 2G CDMA
networks became 3G compliant with the adoption of Revision A to EV-DO, which
made several additions to the protocol while retaining backwards compatibility:
Introduction of several new forward link data rates that
increase the maximum burst rate from 2.45 Mbit/s to 3.1 Mbit/s
Protocols
that would decrease connection establishment time
Ability for
more than one mobile to share the same time slot
Introduction of QoS
flags
All these were put in place to allow for low latency, low bit
rate communications such as VoIP.
The first pre-commercial trial network with 3G was launched
by NTT DoCoMo in Japan in the Tokyo region in May 2001. NTT DoCoMo launched the
first commercial 3G network on 1 October 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). 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.
The high connection speeds of 3G technology enabled a
transformation in the industry: for the first time, media streaming of radio
(and even television) content to 3G handsets became possible, with companies
such as Real Networks and Disney among the early pioneers in this type of
offering.
In the mid-2000s (decade), an evolution of 3G technology
began to be implemented, namely High-Speed Downlink Packet Access (HSDPA). It
is an enhanced 3G (third generation) mobile telephony communications protocol
in the High-Speed Packet Access (HSPA) family, also coined 3.5G, 3G+ or turbo
3G, which allows networks based on Universal Mobile Telecommunications System
(UMTS) to have higher data transfer speeds and capacity. Current HSDPA
deployments support down-link speeds of 1.8, 3.6, 7.2 and 14.0 Mbit/s.
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 were 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.
Although mobile phones had long had the ability to access
data networks such as the Internet, it was not until the widespread
availability of good quality 3G coverage in the mid-2000s (decade) that
specialized devices appeared to access the mobile internet. The first such
devices, known as "dongles", plugged directly into a computer through
the USB port. Another new class of device appeared subsequently, the so-called
"compact wireless router" such as the Novatel MiFi, which makes 3G internet
connectivity available to multiple computers simultaneously over Wi-Fi, rather
than just to a single computer via a USB plug-in.
Such devices became especially popular for use with laptop
computers due to the added portability they bestow. Consequently, some computer
manufacturers started to embed the mobile data function directly into the
laptop so a dongle or MiFi wasn't needed. Instead, the SIM card could be
inserted directly into the device itself to access the mobile data services.
Such 3G-capable laptops became commonly known as "netbooks". Other
types of data-aware devices followed in the netbook's footsteps. By the
beginning of 2010, E-readers, such as the Amazon Kindle and the Nook from
Barnes & Noble, had already become available with embedded wireless
internet, and Apple Computer had announced plans for embedded wireless internet
on its iPad tablet devices beginning that fall.
Native IP networks –
4G
By 2009, it had become clear that, at some point, 3G
networks would be overwhelmed by the growth of bandwidth-intensive applications
like streaming media. Consequently, the industry began looking to
data-optimized 4th-generation technologies, with the promise of speed
improvements up to 10-fold over existing 3G technologies. The first two commercially
available technologies billed as 4G were the WiMAX standard (offered in the
U.S. by Sprint) and the LTE standard, first offered in Scandinavia by
TeliaSonera.
One of the main ways in which 4G differed technologically
from 3G was in its elimination of circuit switching, instead employing an
all-IP network. Thus, 4G ushered in a treatment of voice calls just like any
other type of streaming audio media, utilizing packet switching over internet,
LAN or WAN networks via VoIP.
Thefts
According to the Federal Communications Commission, one out
of three robberies involved the theft of a cellular phone. Police data in San
Francisco showed that one-half of all robberies in 2012 were thefts of cellular
phones. An online petition on Change.org called Secure our Smartphones urged
smartphone manufacturers to install kill switches in their devices to make them
unusable in case of theft. The petition is part of a joint effort by New York
Attorney General Eric Schneider man and San Francisco District Attorney George
Gascon and was directed to the CEOs of the major smartphone manufacturers and telecommunication
carriers. On Monday, 10 June 2013, Apple announced it would install a kill
switch on its next iPhone operating system, due to debut in October 2013.
Satellite mobile
Earth-orbiting satellites can cover remote areas out of
reach of wired networks or where construction of a cellular network is
uneconomic. The Inmarsat satellite telephone system, originally developed in 1979
for safety of life at sea, is now also useful for areas out of reach of
landline, conventional cellular or marine VHF radio stations. In 1998 the
Iridium satellite system was set up, and although the initial operating company
went bankrupt due to high initial expenses, the service is available today
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