4G is the 4th Generation of standards for mobile phones and mobile telecommunications that adheres to the IMT Advanced specifications by the International Telecommunication Union. It is a successor to the 3G and 2G families of standards. Mobile telecommunications that use 4G are expected to provide a comprehensive and secure IP based mobile broadband solution to laptop computer wireless modems, smartphones, and other mobile devices.

In the United States, mobile network operators may brand their services under the term "4G", but in-contrast use 3G transitional based technologies which do not meet criteria to be considered 4G.

History

The nomenclature of the generations generally refers to a change in the fundamental nature of the service, non-backwards compatible transmission technology, wider spectral bandwidth and new frequency bands. New generations have appeared about every ten years since the first move from 1981 analog (1G) to digital (2G) transmission in 1992. This was followed, in 2001, by 3G multi-media support, spread spectrum transmission and at least 200 kbit/s, and followed by 4G.

In mid 1990s, the ITU-R organization specified the IMT-2000 specifications for what standards that should be considered 3G systems. However, the cell phone market only brands some of the IMT-2000 standards as 3G (e.g. WCDMA and CDMA2000), but not all (3GPP EDGE, DECT and mobile-WiMAX all fulfil the IMT-2000 requirements and are formally accepted as 3G standards, but are typically not branded as 3G). In 2008, ITU-R specified the ''International Mobile Telecommunications Advanced (IMT-Advanced) requirements for 4G systems.

For all 4G, the CDMA spread spectrum radio technology used in 3G systems and IS-95 is abandoned and replaced by OFDMA and other frequency-domain equalization schemes. This is combined with MIMO (Multiple In Multiple Out), e.g., multiple antennas, dynamic channel allocation and channel-dependent scheduling.

The world's first publicly available LTE service was opened in the two Scandinavian capitals Stockholm (Ericsson system) and Oslo (a Huawei system) on 14 December 2009, and branded 4G. The user terminals were manufactured by Samsung. Currently, the two publicly available LTE services in the United States are provided by MetroPCS, and Verizon Wireless.

In South Korea, SK Telecom and LG U+ have enabled access to LTE service since 1 July 2011 for data devices, slated to go nationwide by 2012.

4G features predicted in early literature

The 4G system was originally envisioned by the Defense Advanced Research Projects Agency (DARPA). The DARPA selected the distributed architecture, end-to-end Internet protocol (IP), and believed at an early stage in peer-to-peer networking in which every mobile device would be both a transceiver and a router for other devices in the network eliminating the spoke-and-hub weakness of 2G and 3G cellular systems. Since the 2.5G GPRS system, cellular systems have provided dual infrastructures: packet switched nodes for data services, and circuit switched nodes for voice calls. In 4G systems, the circuit-switched infrastructure is abandoned, and only a packet-switched network is provided, while 2.5G and 3G systems require both packet-switched and circuit-switched network nodes, i.e. two infrastructures in parallel. This means that in 4G, traditional voice calls are replaced by IP telephony.

Deployment

In 2002, the strategic vision for 4G—which ITU designated as IMT-Advanced—was laid out.

In 2005, OFDMA transmission technology is chosen as candidate for the HSOPA downlink, later renamed 3GPP Long Term Evolution (LTE) air interface E-UTRA.

In November 2005, KT demonstrated mobile WiMAX service in Busan, South Korea.

In June 2006, KT started the world's first commercial mobile WiMAX service in Seoul, South Korea.

In mid-2006, Sprint Nextel announced that it would invest about US$5 billion in a WiMAX technology buildout over the next few years ($}} in real terms). Since that time Sprint has faced many setbacks, that have resulted in steep quarterly losses. On May 7, 2008, Sprint, Imagine, Google, Intel, Comcast, Bright House, and Time Warner announced a pooling of an average of 120 MHz of spectrum; Sprint merged its Xohm WiMAX division with Clearwire to form a company which will take the name "Clear". In February 2007, the Japanese company NTT DoCoMo tested a 4G communication system prototype with 4x4 MIMO called VSF-OFCDM at 100 Mbit/s while moving, and 1 Gbit/s while stationary. NTT DoCoMo completed a trial in which they reached a maximum packet transmission rate of approximately 5 Gbit/s in the downlink with 12x12 MIMO using a 100 MHz frequency bandwidth while moving at 10 km/h, and is planning on releasing the first commercial network in 2010. In September 2007, NTT Docomo demonstrated e-UTRA data rates of 200 Mbit/s with power consumption below 100 mW during the test. In January 2008, a U.S. Federal Communications Commission (FCC) spectrum auction for the 700 MHz former analog TV frequencies began. As a result, the biggest share of the spectrum went to Verizon Wireless and the next biggest to AT&T.; Both of these companies have stated their intention of supporting LTE. In January 2008, EU commissioner Viviane Reding suggested re-allocation of 500–800 MHz spectrum for wireless communication, including WiMAX. On 15 February 2008 - Skyworks Solutions released a front-end module for e-UTRAN. In 2008, ITU-R established the detailed performance requirements of IMT-Advanced, by issuing a Circular Letter calling for candidate Radio Access Technologies (RATs) for IMT-Advanced.

In April 2008, just after receiving the circular letter, the 3GPP organized a workshop on IMT-Advanced where it was decided that LTE Advanced, an evolution of current LTE standard, will meet or even exceed IMT-Advanced requirements following the ITU-R agenda.

In April 2008, LG and Nortel demonstrated e-UTRA data rates of 50 Mbit/s while travelling at 110 km/h. On 12 November 2008, HTC announced the first WiMAX-enabled mobile phone, the Max 4G In December 2008, San Miguel Corporation, Asia's largest food and beverage conglomerate, has signed a memorandum of understanding with Qatar Telecom QSC (Qtel) to build wireless broadband and mobile communications projects in the Philippines. The joint-venture formed wi-tribe Philippines, which offers 4G in the country. Around the same time Globe Telecom rolled out the first WiMAX service in the Philippines. On 3 March 2009, Lithuania's LRTC announcing the first operational "4G" mobile WiMAX network in Baltic states. In December 2009, Sprint began advertising "4G" service in selected cities in the United States, despite average download speeds of only 3–6 Mbit/s with peak speeds of 10 Mbit/s (not available in all markets). On 14 December 2009, the first commercial LTE deployment was in the Scandinavian capitals Stockholm and Oslo by the Swedish-Finnish network operator TeliaSonera and its Norwegian brandname NetCom (Norway). TeliaSonera branded the network "4G". The modem devices on offer were manufactured by Samsung (dongle GT-B3710), and the network infrastructure created by Huawei (in Oslo) and Ericsson (in Stockholm). TeliaSonera plans to roll out nationwide LTE across Sweden, Norway and Finland. TeliaSonera used spectral bandwidth of 10 MHz, and single-in-single-out, which should provide physical layer net bitrates of up to 50 Mbit/s downlink and 25 Mbit/s in the uplink. Introductory tests showed a TCP throughput of 42.8 Mbit/s downlink and 5.3 Mbit/s uplink in Stockholm. On 25 February 2010, Estonia's EMT opened LTE "4G" network working in test regime. On 4 June 2010, Sprint Nextel released the first WiMAX smartphone in the US, the HTC Evo 4G. In July 2010, Uzbekistan's MTS deployed LTE in Tashkent.

On 25 August 2010, Latvia's LMT opened LTE "4G" network working in test regime 50% of territory.

On 6 December 2010, at the ITU World Radiocommunication Seminar 2010, the ITU stated that LTE, WiMax and similar "evolved 3G technologies" could be considered "4G". On 12 December 2010, VivaCell-MTS launches in Armenia 4G/LTE commercial test network with a live demo conducted in Yerevan. On 28 April 2011, Lithuania's Omnitel opened LTE "4G" network working in 5 biggest cities.

Adoption

In May 2005, Digiweb, an Irish fixed and wireless broadband company, announced that they had received a mobile communications license from the Irish Telecoms regulator, ComReg. This service will be issued the mobile code 088 in Ireland and will be used for the provision of 4G Mobile communications. Digiweb launched a mobile broadband network using FLASH-OFDM technology at 872 MHz.

On July 7, 2008, South Korea announced plans to spend 60 billion won, or US$58,000,000, on developing 4G and even 5G technologies, with the goal of having the highest mobile phone market share by 2012, and the hope of an international standard.

Telus and Bell Canada, the major Canadian cdmaOne and EV-DO carriers, have announced that they will be cooperating towards building a fourth generation (4G) LTE wireless broadband network in Canada. As a transitional measure, they are implementing 3G UMTS that went live in November 2009.

In the United Kingdom, Telefónica O₂ is to use Slough as a guinea pig in testing the 4G network and has called upon Huawei to install LTE technology in six masts across the town to allow people to talk to each other via HD video conferencing and play PlayStation games while on the move.

The U.S. FCC is exploring the possibility of deployment and operation of a nationwide 4G public safety network which would allow first responders to seamlessly communicate between agencies and across geographies, regardless of devices. In June 2010 the FCC released a comprehensive white paper which indicates that the 10 MHz of dedicated spectrum currently allocated from the 700 MHz spectrum for public safety will provide adequate capacity and performance necessary for normal communications as well as serious emergency situations.

TeliaSonera started deploying LTE (branded "4G") in Stockholm and Oslo November 2009 (as seen above), and in several Swedish, Norwegian, and Finnish cities during 2010. In June 2010, Swedish television companies used 4G to broadcast live television from the Swedish Crown Princess' Royal Wedding.

Safaricom, a telecommunication company in East& Central Africa, began its setup of a 4G network in October 2010 after the now retired& Kenya Tourist Board Chairman, Michael Joseph, regarded their 3G network as a white elephant i.e. it failed to perform to expectations. Huawei was given the contract the network is set to go fully commercial by the end of Q1 of 2011

Telstra announced on 15 February 2011, that it intends to upgrade its current Next G network to 4G with Long Term Evolution (LTE) technology in the central business districts of all Australian capital cities and selected regional centers by the end of 2011.

Sri Lanka Telecom Mobitel and Dialog Axiata announced that for the first time in South Asia, Sri Lanka has successfully tested and demonstrated 4G technology on 6 May (Sri Lanka Telecom Mobitel) and 7 May 2011 (Dialog Axiata) and began the setup of their 4G networks in Sri Lanka.

On May 2011, Brazil's Communication Ministry announced that the 12 host cities for the 2014 FIFA World Cup to be held there will be the first to have their networks upgraded to 4G.

Features

Cellular systems such as 4G allow seamless mobility; thus a file transfer is not interrupted in case a terminal moves from one cell (one base station coverage area) to another, but handover is carried out. The terminal also keeps the same IP address while moving, meaning that a mobile server is reachable as long as it is within the coverage area of any server. In 4G systems this mobility is provided by the mobile IP protocol, part of IP version 6, while in earlier cellular generations it was only provided by physical layer and datalink layer protocols. In addition to seamless mobility, 4G provides flexible interoperability of the various kinds of existing wireless networks, such as satellite, cellular wirelss, WLAN, PAN and systems for accessing fixed wireless networks.

United States 4G

In marketing, mobile network operators brand under the term "4G" to signal the next generation of wireless experiences. But underneath, operators may use 3G transitional based technologies which do not meet criteria to be considered 4G under the IMT Advanced specifications.

Types of 4G Used

As of August 2011, U.S. carriers currently use the following types of 4G technologies:

AT&T; = HSPA+ (21 mbps)

Sprint = WiMax

Verizon = LTE

T-Mobile = HSPA+ (42 mbps & 21 mbps)

Experts consider LTE to be the highest quality network in the United States now and for the foreseeable future. Networks test have shown HSPA+ and WiMax perform significantly worse than LTE and AT&T; and Sprint have both made plans to integrate this technology into their network in the future.

In 2011, multiple independent researchers have ranked 4G speed and experiences and have found consistent results. Verizon's 4G LTE has statistically significantly outperformed other network's 4G on tests to date (August 2011).

2011 U.S. Speed Test Results

This independent speed test took into account coverage as well as downloading, uploading, and webpage loading speeds in locations all across America.

Rank. Carrier, 4G Technology - Score # Verizon, 4G LTE = 93 # T-Mobile, HSPA+ (42&21 mbps) = 75 # AT&T; HSPA+ (21 mbps) = 63 # Sprint, WiMax = 47

This study found "4G LTE" not only to be faster than other types of U.S. 4G, but also faster than DSL or Cable Internet in some areas.

LTE

LTE has emerged as the next generation wireless technology three of the four largest U.S. carriers have chosen. As of August 2011, analysts estimate that one million LTE smart phones are in use by consumers across America.

Verizon was the first large national carrier to provide access to LTE and has already covered over half of America (160 million people) with this technology. Verizon has plans to cover its entire 3G footprint with nationwide LTE by 2013.

In June 2011, AT&T;'s CEO announced that it would be about 2-3 years until AT&T; will reach virtual parity with Verizon's LTE [All Things Digital Conference] They have plans to launch LTE in 5 markets late-Summer 2011 and have a goal to be in 15 markets by the end of 2011. They have a stated commitment to expanding the network before focusing on LTE product development. Initial LTE offerings will include a hotspot and wireless card and AT&T; said they will have their first LTE smartphone available before the end of the year. Current AT&T; 4G (HSPA+) smart phones will not work with the significantly faster LTE network.

In June 2011, Sprint signed a 15-year deal to partner with LightSquared Inc. in developing, deploying, and operating LightSquared's LTE network. As of August 2011, no launch markets or dates have been released.

Evolution

A major issue in 4G systems is to make the high bit rates available in a larger portion of the cell, especially to users in an exposed position in between several base stations. In current research, this issue is addressed by macro-diversity techniques, also known as group cooperative relay, and also by beam-division multiple access.

Pervasive networks are an amorphous and at present entirely hypothetical concept where the user can be simultaneously connected to several wireless access technologies and can seamlessly move between them (See vertical handoff, IEEE 802.21). These access technologies can be Wi-Fi, UMTS, EDGE, or any other future access technology. Included in this concept is also smart-radio (also known as cognitive radio) technology to efficiently manage spectrum use and transmission power as well as the use of mesh routing protocols to create a pervasive network.

See also

Mobile radio telephone (also known as "0G")

1G

2G

3G

References

External links

3GPP LTE Encyclopedia

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{{s-ttl|title=Mobile Telephony Generations |years=}}

Category:Software-defined radio Category:Emerging standards

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