A handheld mobile radio telephone service was envisioned in the early stages of radio engineering. In 1917, Finnish inventor Eric Tigerstedt filed a patent for a "pocket-size folding telephone with a very thin carbon microphone". Early predecessors of cellular phones included analog radio communications from ships and trains. The race to create truly portable telephone devices began after World War II, with developments taking place in many countries. The advances in mobile telephony have been traced in successive "generations", starting with the early "0G" (zeroth generation) services, such as Bell System's Mobile Telephone Service and its successor, the Improved Mobile Telephone Service. These "0G" systems were not cellular, supported few simultaneous calls, and were very expensive.
The first handheld mobile cell phone was demonstrated by Motorola in 1973. The first commercial automated cellular network was launched in Japan by Nippon Telegraph and Telephone in 1979. This was followed in 1981 by the simultaneous launch of the Nordic Mobile Telephone (NMT) system in Denmark, Finland, Norway and Sweden.[6] Several other countries then followed in the early to mid-1980s. These first-generation (1G) systems could support far more simultaneous calls, but still used analog technology.
In 1991, the second-generation (2G) digital cellular technology was launched in Finland by Radiolinja on the GSM standard. This sparked competition in the sector as the new operators challenged the incumbent 1G network operators.
Ten years later, in 2001, the third generation (3G) was launched in Japan by NTT DoCoMo on theWCDMA standard.[7] This was followed by 3.5G, 3G+ or turbo 3G enhancements based on the high-speed packet access (HSPA) family, allowing UMTS networks to have higher data transfer speeds and capacity.
By 2009, it had become clear that, at some point, 3G networks would be overwhelmed by the growth of bandwidth-intensive applications, such as streaming media.[8] Consequently, the industry began looking to data-optimized fourth-generation technologies, with the promise of speed improvements up to ten-fold over existing 3G technologies. The first two commercially available technologies billed as 4G were the WiMAX standard, offered in North America by Sprint, and the LTE standard, first offered in Scandinavia byTeliaSonera.
Features
Main article: Mobile phone features
See also: Smartphone
All mobile phones have a variety of features in common, but manufacturers seek product differentiation by adding functions to attract consumers. This competition has led to great innovation in mobile phone development over the past 20 years.
The common components found on all phones are:
- A battery, providing the power source for the phone functions.
- An input mechanism to allow the user to interact with the phone. The most common input mechanism is a keypad, but touch screens are also found in most smartphones.
- A screen which echoes the user's typing, displays text messages, contacts and more.
- Basic mobile phone services to allow users to make calls and send text messages.
- All GSM phones use a SIM card to allow an account to be swapped among devices. Some CDMA devices also have a similar card called a R-UIM.
- Individual GSM, WCDMA, iDEN and some satellite phone devices are uniquely identified by an International Mobile Equipment Identity (IMEI) number.
Low-end mobile phones are often referred to as feature phones, and offer basic telephony. Handsets with more advanced computing ability through the use of native software applications became known as smartphones.
Several phone series have been introduced to address specific market segments, such as the RIM BlackBerry focusing on enterprise/corporate customer email needs, the Sony-Ericsson 'Walkman' series of music/phones and 'Cyber-shot' series of camera/phones, the Nokia Nseries of multimedia phones, the Palm Pre, the HTC Dream and the AppleiPhone.
Sound quality
In sound quality, smartphones and feature phones vary little. Some audio-quality enhancing features, such as Voice over LTE and HD Voice, have appeared and are often available on newer smartphones. Sound quality can remain a problem with both, as this depends not so much on the phone itself, as on the quality of the network and, in long distance calls, the bottlenecks/choke points met along the way.[9][10] As such, for long-distance calls even features such as Voice over LTE and HD Voice may not improve things. In some cases smartphones can improve audio quality even on long-distance calls, by using a VoIP phone service, with someone else's WiFi/internet connection.[11]
Text messaging
Main article: SMS
The most commonly used data application on mobile phones is Short Message Service (SMS) text messaging. The first SMS message was sent from a computer to a mobile phone in 1992 in the UK, while the first person-to-person SMS from phone to phone was sent in Finland in 1993.
The first mobile news service, delivered via SMS, was launched in Finland in 2000,[citation needed] and subsequently many organizations provided "on-demand" and "instant" news services by SMS.
Multimedia Messaging Service (MMS) was introduced in 2001.[citation needed]
SIM card
Main articles: Subscriber Identity Module and Removable User Identity Module
GSM feature phones require a small microchip called a Subscriber Identity Module or SIM card, in order to function. The SIM card is approximately the size of a small postage stamp and is usually placed underneath the battery in the rear of the unit. The SIM securely stores theservice-subscriber key (IMSI) and the Ki used to identify and authenticate the user of the mobile phone. The SIM card allows users to change phones by simply removing the SIM card from one mobile phone and inserting it into another mobile phone or broadband telephony device, provided that this is not prevented by a SIM lock.
The first SIM card was made in 1991 by Munich smart card maker Giesecke & Devrient for the Finnish wireless network operatorRadiolinja.[citation needed]
Multi-card hybrid phones
A hybrid mobile phone can hold up to four SIM cards. SIM and R-UIM cards may be mixed together to allow both GSM and CDMA networks to be accessed.
From 2010 onwards, such phones became popular in India and Indonesia and other emerging markets,[12] and this was attributed to the desire to obtain the lowest on-net calling rate. In Q3 2011, Nokia shipped 18 million of its low-cost dual SIM phone range in an attempt to make up for lost ground in the higher-end smartphone market.[13]
Kosher phones
There are Jewish orthodox religious restrictions which, by some interpretations, standard mobile telephones overstep. To deal with this problem, some rabbinical organizations have recommended that phones with text-messaging capability not be used by children.[14] Phones with restricted features are known as kosher phones and have rabbinicalapproval for use in Israel and elsewhere by observant Orthodox Jews. Although these phones are intended to prevent immodesty, some vendors report good sales to adults who prefer the simplicity of the devices. Some phones are approved for use by essential workers (such as health, security and public service workers) on the sabbath, even though the use of any electrical device is generally prohibited during this time.[15]
Mobile phone operators
Main article: Mobile phone operator
The world's largest individual mobile operator by number of subscribers is China Mobile, which has over 500 million mobile phone subscribers.[16] Over 50 mobile operators have over ten million subscribers each, and over 150 mobile operators had at least one million subscribers by the end of 2009.[17] In 2014, there were more than seven billion mobile phone subscribers worldwide, a number that is expected to keep growing.
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