From Wikipedia, the free encyclopedia
This article has multiple issues. Please help
or discuss these issues on the . ()
This article needs additional citations for . Please help
by . Unsourced material may be challenged and removed. (January 2011) ()
4G is the fourth generation of
technology, succeeding . A 4G system must provide capabilities defined by
in . Potential and current applications include amended
access, , gaming services,
The first-release
(LTE) standard (a 4G candidate system) has been commercially deployed in Oslo, Norway, and Stockholm, Sweden since 2009. It has, however, been debated whether first-release versions should be considered 4G , as discussed in the
section below.
In March 2008, the
(ITU-R) specified a set of requirements for 4G standards, named the International Mobile Telecommunications Advanced (IMT-Advanced) specification, setting peak speed requirements for 4G service at 100
(Mbit/s) for high mobility communication (such as from trains and cars) and 1
(Gbit/s) for low mobility communication (such as pedestrians and stationary users).
Since the first-release versions of
support much less than 1 Gbit/s peak bit rate, they are not fully IMT-Advanced compliant, but are often branded 4G by service providers. According to operators, a generation of the network refers to the deployment of a new non-backward-compatible technology. On December 6, 2010, ITU-R recognized that these two technologies, as well as other beyond-3G technologies that do not fulfill the IMT-Advanced requirements, could nevertheless be considered "4G", provided they represent forerunners to IMT-Advanced compliant versions and "a substantial level of improvement in performance and capabilities with respect to the initial third generation systems now deployed".
(also known as WirelessMAN-Advanced or IEEE 802.16m') and
(LTE-A) are IMT-Advanced compliant backwards compatible versions of the above two systems, standardized during the spring 2011,[] and promising speeds in the order of 1 Gbit/s. Services were expected in 2013.[]
As opposed to earlier generations, a 4G system does not support traditional
telephony service, but all- (IP) based communication such as . As seen below, the
radio technology used in 3G systems, is abandoned in all 4G candidate systems and replaced by
transmission and other
(FDE) schemes, making it possible to transfer very high bit rates despite extensive
(echoes). The peak bit rate is further improved by
arrays for
(MIMO) communications.
In the field of mobile communications, a "generation" generally refers to a change in the fundamental nature of the service, non-backwards-compatible transmission technology, higher peak bit rates, new frequency bands, wider channel frequency bandwidth in Hertz, and higher capacity for many simultaneous data transfers (higher
in /second/Hertz/site).
New mobile 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,
transmission and, at least, 200
peak bit rate, in
to be followed by "real" 4G, which refers to all- (IP)
networks giving mobile ultra-broadband (gigabit speed) access.
While the ITU has adopted recommendations for technologies that would be used for future global communications, they do not actually perform the standardization or development work themselves, instead relying on the work of other standard bodies such as IEEE, The Wi MAX Forum, and 3GPP.
In the mid-1990s, the
standardization organization released the
requirements as a framework for what standards should be considered
systems, requiring 200 kbit/s peak bit rate. In 2008, ITU -R specified the
(International Mobile Telecommunications Advanced) requirements for 4G systems.
The fastest 3G-based standard in the
family is the
standard, which is commercially available since 2009 and offers 28 Mbit/s downstream (22 Mbit/s upstream) without , i.e. only with one antenna, and in 2011 accelerated up to 42 Mbit/s peak bit rate downstream using either
(simultaneous use of two 5 MHz UMTS carriers) or 2x2 MIMO. In theory speeds up to 672 Mbit/s are possible, but have not been deployed yet. The fastest 3G-based standard in the
family is the , which is available since 2010 and offers 15.67 Mbit/s downstream.
This article refers to 4G using IMT-Advanced (International Mobile Telecommunications Advanced), as defined by . An IMT-Advanced
must fulfill the following requirements:
Be based on an all-IP packet switched network.
Have peak data rates of up to approximately 100 Mbit/s for high mobility such as mobile access and up to approximately 1 Gbit/s for low mobility such as nomadic/local wireless access.
Be able to dynamically share and use the network resources to support more simultaneous users per cell.
Use scalable channel bandwidths of 5–20 MHz, optionally up to 40 MHz.Rumney, Moray (September 2008).
(PDF). Agilent Measurement Journal. Archived from
(PDF) on January 17, 2016.
of 15-bit/s/Hz in the downlink, and 6.75-bit/s/Hz in the up link (meaning that 1 Gbit/s in the downlink should be possible over less than 67 MHz bandwidth).
is, in indoor cases, 3-bit/s/Hz/cell for downlink and 2.25-bit/s/Hz/cell for up link.
Smooth handovers across heterogeneous networks.
In September 2009, the technology proposals were submitted to the International Telecommunication Union (ITU) as 4G candidates. Basically all proposals are based on two technologies.:
standardized by the
standardized by the
(i.e. WiMAX)
Implementations of Mobile WiMAX and first-release LTE are largely considered a stopgap solution that will offer a considerable boost until WiMAX 2 (based on the 802.16m spec) and LTE Advanced are deployed. The latter's standard versions were ratified in spring 2011, but are still far from being implemented.
The first set of 3GPP requirements on LTE Advanced was approved in June 2008. LTE Advanced was to be standardized in 2010 as part of Release 10 of the 3GPP specification. LTE Advanced will be based on the existing LTE specification Release 10 and will not be defined as a new specification series. A summary of the technologies that have been studied as the basis for LTE Advanced is included in a technical report.
Some sources consider first-release LTE and Mobile WiMAX implementations as pre-4G or near-4G, as they do not fully comply with the planned requirements of 1 Gbit/s for stationary reception and 100 Mbit/s for mobile.
Confusion has been caused by some mobile carriers who have launched products advertised as 4G but which according to some sources are pre-4G versions, commonly referred to as '3.9G', which do not follow the ITU-R defined principles for 4G standards, but today can be called 4G according to ITU-R. Vodafone NL for example, advertised LTE as '4G', while advertising now LTE Advanced as their '4G+' service which actually is (True) 4G. A common argument for branding 3.9G systems as new-generation is that they use different frequency bands from 3G technologies ; that they are based on a new radio-interface paradigm ; and that the standards are not backwards compatible with 3G, whilst some of the standards are forwards compatible with IMT-2000 compliant versions of the same standards.
As of October 2010, ITU-R Working Party 5D approved two industry-developed technologies (LTE Advanced and WirelessMAN-Advanced) for inclusion in the ITU's International Mobile Telecommunications Advanced program ( program), which is focused on global communication systems that will be available several years from now.
(Long Term Evolution Advanced) is a candidate for
standard, formally submitted by the
organization to ITU-T in the fall 2009, and expected to be released in 2013. The target of 3GPP LTE Advanced is to reach and surpass the ITU requirements. LTE Advanced is essentially an enhancement to LTE. It is not a new technology, but rather an improvement on the existing LTE network. This upgrade path makes it more cost effective for vendors to offer LTE and then upgrade to LTE Advanced which is similar to the upgrade from WCDMA to HSPA. LTE and LTE Advanced will also make use of additional spectrums and multiplexing to allow it to achieve higher data speeds. Coordinated Multi-point Transmission will also allow more system capacity to help handle the enhanced data speeds. Release 10 of LTE is expected to achieve the IMT Advanced speeds. Release 8 currently supports up to 300 Mbit/s of download speeds which is still short of the IMT-Advanced standards.
Data speeds of LTE-Advanced
LTE Advanced
Peak download
1000 Mbit/s
Peak upload
0500 Mbit/s
evolution of 802.16e is under development, with the objective to fulfill the IMT-Advanced criteria of 1 Gbit/s for stationary reception and 100 Mbit/s for mobile reception.
-branded Samsung LTE modem
The pre-4G
(LTE) technology is often branded "4G - LTE", but the first LTE release does not fully comply with the IMT-Advanced requirements. LTE has a theoretical
capacity of up to 100 Mbit/s in the downlink and 50 Mbit/s in the uplink if a 20 MHz channel is used — and more if
(MIMO), i.e. antenna arrays, are used.
The physical radio interface was at an early stage named High Speed
Packet Access (HSOPA), now named
(E-UTRA). The first
USB dongles do not support any other radio interface.
The world's first publicly available LTE service was opened in the two Scandinavian capitals,
systems) and
system) on December 14, 2009, and branded 4G. The user terminals were manufactured by Samsung. As of November 2012, the five publicly available LTE services in the United States are provided by , , , , , and .
T-Mobile Hungary launched a public beta test (called friendly user test) on 7 October 2011, and has offered commercial 4G LTE services since 1 January 2012.[]
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. KT Telecom closed its 2G service by March 2012, and complete the nationwide LTE service in the same frequency around 1.8 GHz by June 2012.
In the United Kingdom, LTE services were launched by
in October 2012, and by
in August 2013.
Data speeds of LTE
Peak download
0100 Mbit/s
Peak upload
0050 Mbit/s
(IEEE 802.16e-2005) mobile wireless broadband access (MWBA) standard (also known as
in South Korea) is sometimes branded 4G, and offers peak data rates of 128 Mbit/s downlink and 56 Mbit/s uplink over 20 MHz wide channels.[]
In June 2006, the world's first commercial mobile WiMAX service was opened by
has begun using Mobile WiMAX, as of 29 September 2008, branding it as a "4G" network even though the current version does not fulfill the IMT Advanced requirements on 4G systems.
In Russia, Belarus and Nicaragua WiMax broadband internet access was offered by a Russian company , and was also branded 4G, .
Data speeds of WiMAX
Peak download
0128 Mbit/s
Peak upload
0056 Mbit/s
This section possibly contains
of published material that conveys ideas not
to the original sources. Relevant discussion may be found on the . (April 2017) ()
(LTE) and WiMAX are being vigorously promoted in the global telecommunications industry, the former (LTE) is also the most powerful 4G mobile communications leading technology and has quickly occupied the Chinese market. , one of the two variants of the LTE air interface technologies, is not yet mature, but many domestic and international wireless carriers are, one after the other turning to TD-LTE.
IBM's data shows that 67% of the operators are considering LTE because this is the main source of their future market. The above news also confirms IBM's statement that while only 8% of the operators are considering the use of WiMAX, WiMAX can provide the fastest network transmission to its customers on the market and could challenge LTE.
TD-LTE is not the first 4G wireless mobile broadband network data standard, but it is China's 4G standard that was amended and published by China's largest telecom operator – . After a series of field trials, is expected to be released into the commercial phase in the next two years. Ulf Ewaldsson, Ericsson's vice president said: "the Chinese Ministry of Industry and China Mobile in the fourth quarter of this year will hold a large-scale field test, by then, Ericsson will help the hand." But viewing from the current development trend, whether this standard advocated by China Mobile will be widely recognized by the international market is still debatable.
UMB () was the brand name for a discontinued 4G project within the
standardization group to improve the
mobile phone standard for next generation applications and requirements. In November 2008, , UMB's lead sponsor, announced it was ending development of the technology, favouring LTE instead. The objective was to achieve data speeds over 275 Mbit/s downstream and over 75 Mbit/s upstream.
At an early stage the
system was expected to be further developed into a 4G standard.
system (or HC-SDMA, High Capacity Spatial Division Multiple Access) was at an early stage considered to be a 4G predecessor. It was later further developed into the
(MBWA) system, also known as IEEE 802.20.
This section needs additional citations for . Please help
by . Unsourced material may be challenged and removed. (August 2015) ()
The following key features can be observed in all suggested 4G technologies:
Physical layer transmission techniques are as follows:
: To attain ultra high spectral efficiency by means of spatial processing including multi-antenna and multi-user MIMO
Frequency-domain-equalization, for example multi-carrier modulation () in the downlink or single-carrier frequency-domain-equalization (SC-FDE) in the uplink: To exploit the frequency selective channel property without complex equalization
Frequency-domain statistical multiplexing, for example () or (single-carrier FDMA) (SC-FDMA, a.k.a. linearly precoded OFDMA, LP-OFDMA) in the uplink: Variable bit rate by assigning different sub-channels to different users based on the channel conditions
: To minimize the required
at the reception side
: To use the time-varying channel
and error-correcting codes
utilized for mobility
(home nodes connected to fixed Internet broadband infrastructure)
As opposed to earlier generations, 4G systems do not support circuit switched telephony. IEEE 802.20, UMB and OFDM standards lack
support, also known as .
This section contains information of unclear or questionable
to the article's subject matter. Please
this section by clarifying or removing . If importance cannot be established, the section is likely to be moved to another article, , or removed.
Find sources:  –  ·  ·  ·  ·
(May 2010) ()
Recently, new access schemes like
(SC-FDMA), , and
(MC-CDMA) are gaining more importance for the next generation systems. These are based on efficient
algorithms and frequency domain equalization, resulting in a lower number of multiplications per second. They also make it possible to control the bandwidth and form the spectrum in a flexible way. However, they require advanced dynamic channel allocation and adaptive traffic scheduling.
is using OFDMA in the downlink and in the uplink. For the , OFDMA is u by contrast,
is used for the uplink since OFDMA contributes more to the
related issues and results in nonlinear operation of amplifiers. IFDMA provides less power fluctuation and thus requires energy-inefficient linear amplifiers. Similarly, MC-CDMA is in the proposal for the
standard. These access schemes offer the same efficiencies as older technologies like CDMA. Apart from this, scalability and higher data rates can be achieved.
The other important advantage of the above-mentioned access techniques is that they require less complexity for equalization at the receiver. This is an added advantage especially in the
environments since the
transmission of MIMO systems inherently require high complexity equalization at the receiver.
In addition to improvements in these multiplexing systems, improved
techniques are being used. Whereas earlier standards largely used , more efficient systems such as 64 are being proposed for use with the
standards.
Unlike 3G, which is based on two parallel infrastructures consisting of
network nodes, 4G will be based on packet switching only. This will require
data transmission.
By the time that 4G was deployed, the process of
was expected to be in its final stages. Therefore, in the context of 4G,
is essential to support a large number of wireless-enabled devices. By increasing the number of
available, IPv6 removes the need for
(NAT), a method of sharing a limited number of addresses among a larger group of devices, although NAT will still be required to communicate with devices that are on existing
As of June 2009,
has posted [] that require any 4G devices on its network to support IPv6.
The performance of radio communications depends on an antenna system, termed
or . Recently,
are emerging to achieve the goal of 4G systems such as high rate, high reliability, and long range communications. In the early 1990s, to cater for the growing data rate needs of data communication, many transmission schemes were proposed. One technology, , gained importance for its bandwidth conservation and power efficiency. Spatial multiplexing involves deploying multiple antennas at the transmitter and at the receiver. Independent streams can then be transmitted simultaneously from all the antennas. This technology, called
(as a branch of ), multiplies the base data rate by (the smaller of) the number of transmit antennas or the number of receive antennas. Apart from this, the reliability in transmitting high speed data in the fading channel can be improved by using more antennas at the transmitter or at the receiver. This is called transmit or receive diversity. Both transmit/receive diversity and transmit spatial multiplexing are categorized into the space-time coding techniques, which does not necessarily require the channel knowledge at the transmitter. The other category is closed-loop multiple antenna technologies, which require channel knowledge at the transmitter.
One of the key technologies for 4G and beyond is called Open Wireless Architecture (OWA), supporting multiple wireless air interfaces in an open architecture platform.
is one form of open wireless architecture (OWA). Since 4G is a collection of wireless standards, the final form of a 4G device will constitute various standards. This can be efficiently realized using SDR technology, which is categorized to the area of the radio convergence.
The 4G system was originally envisioned by the Defense Advanced Research Projects Agency (DARPA).[] The DARPA selected the distributed architecture and 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
is provided, while 2.5G and 3G systems require both packet-switched and circuit-switched , i.e. two infrastructures in parallel. This means that in 4G, traditional voice calls are replaced by IP telephony.
In 2002, the strategic vision for 4G — which
designated as — was laid out.
was first proposed by
transmission technology is chosen as candidate for the
downlink, later renamed 3GPP Long Term Evolution (LTE) air interface .
In November 2005,
demonstrated mobile WiMAX service in Busan, South Korea.
In April 2006,
started the world's first commercial mobile WiMAX service in Seoul, South Korea.
In mid-2006,
announced that it would invest about US$5 billion in a
technology buildout over the next few years ($5.94 billion in
terms). Since that time Sprint has faced many setbacks that have resulted in steep quarterly losses. On 7 May 2008, , , , , , , and
announced a pooling of an average of 120 MH Sprint merged its
WiMAX division with
to form a company which will take the name "Clear".
In February 2007, the
tested a 4G communication system prototype with 4×4
at 100 /s while moving, and 1 /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 12×12 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.
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 .
In January 2008, EU commissioner
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 November 2008,
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,
announced the first WiMAX-enabled mobile phone, the
On 15 December 2008, , the largest food and beverage conglomerate in southeast Asia, has signed a memorandum of understanding with Qatar Telecom QSC () 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
rolled out the first WiMAX service in the Philippines.
On 3 March 2009, Lithuania's LRTC announcing the first operational "4G"
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
by the Swedish-Finnish network operator
and its Norwegian brandname . TeliaSonera branded the network "4G". The modem devices on offer were manufactured by
(dongle GT-B3710), and the network infrastructure created by
(in Oslo) and
(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
of up to 50 Mbit/s downlink and 25 Mbit/s in the uplink. Introductory tests showed a
of 42.8 Mbit/s downlink and 5.3 Mbit/s uplink in Stockholm.
On 4 June 2010,
released the first WiMAX smartphone in the US, the .
On November 4, 2010, the
Craft offered by
is the first commercially available LTE smartphone
On 6 December 2010, at the ITU World Radiocommunication Seminar 2010, the
stated that ,
and similar "evolved 3G technologies" could be considered "4G".
In 2011, 's
launched a pre-4G HSPA+ network in the country.
In 2011, 's
launched a pre-4G HSPA+ network with nationwide availability.
On March 17, 2011, the
offered by Verizon in the U.S. was the second LTE smartphone to be sold commercially.
In February 2012,
demonstrated
over LTE, utilizing the new eMBMS service (enhanced ).
Since 2009 the LTE-Standard has strongly evolved over the years, resulting in many deployments by various operators across the globe. For an overview of commercial LTE networks and their respective historic development see: . Among the vast range of deployments many operators are considering the deployment and operation of LTE networks. A compilation of planned LTE deployments can be found at: .
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
techniques, also known as , and also by .
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 , ). These access technologies can be , , , or any other future access technology. Included in this concept is also smart-radio (also known as ) technology to efficiently manage spectrum use and transmission power as well as the use of
protocols to create a pervasive network.
, , Approved in November 2008
. International Telecommunication Union.
LteWorld February 7, 2012
Vilches, J. (April 29, 2010). . TechSpot 2016.
. Nomor Research 2016.
. 3GPP 2013.
. 3GPP 2013.
(press release). ITU. 21 October 2010
Parkvall, S Dahlman, E Furusk?r, A Jading, Y Olsson, M W?nstedt, S Zangi, Kambiz (21–24 September 2008).
Fall 2008. Ericsson Research. Stockholm 2010.
Parkvall, S Astely, David (April 2009). . . 4 (3): 146–54. :.
(PDF). ieee802.org. April 4, 2008.
. < 2010.[]
. MetroPCS IR. 21 September 2010. Archived from
Jason Hiner (12 January 2011). . TechRepublic 2011.
Brian Bennet (5 April 2012). . CNet 2012.
. PC Magazine. 27 June .
. T-Mobile USA. 6 April .
. 5 July .
. EE. October 30, .
Miller, Joe (August 29, 2013). . BBC News 2013.
Shukla, Anuradha (October 10, 2011). . Asia-Pacific Business and Technology Report 2011.
. Engadget. March 23, 2010.
from the original on March 25, .
. May 21, 2010 – via Reuters.
, Reuters, November 13th, 2008
G. F E. Z H. B W. S K. G M. de Courville (2004).
(PDF). WWRF. Archived from
(PDF) on .
Morr, Derek (June 9, 2009).
Zheng, P; Peterson, L; Davie, B; Farrel, A (2009). "Wireless Networking Complete". Morgan Kaufmann
Alabaster, Jay (20 August 2012). . Network World. IDG. Archived from
on December 3, .
. . November 15, 2005. Archived from
on May 29, .
. March 2011.
. Sprint. Archived from
on February 22, .
Federal Reserve Bank of Minneapolis Community Development Project. . Federal Reserve Bank of Minneapolis 2017.
Press. February 9, 2007.
Reynolds, Melanie (September 14, 2007). . . Archived from
on September 27, .
from the original on January 24, .
from the original on December 14, .
(free registration required). Wireless News. February 14, .
. WirelessWeek. February 15, 2008. Archived from
on August 19, .
. Skyworks press release. 11 February .
ITU-R Report M.2134, “Requirements related to technical performance for IMT-Advanced radio interface(s),” November 2008.
. Archived from
(Press release). HTC Corporation. 12 November 2008. Archived from
. Archived from the original on February 18, 2009. San Miguel Corporation, December 15, 2008
(Press release). WiMAX Forum. 3 March 2009. Archived from
. . Archived from
on April 5, .
. . December 14, 2009. Archived from
– NetCom 4G (in English)
. Daily Mobile 2016.
Anand Lal Shimpi (June 28, 2010). .
. <. March 16, .
. Ericsson 2012.
IT R&D program of /IITA: 2008-F-004-01 “5G mobile communication systems based on beam-division multiple access and relays with group cooperation”.
Brian Woerner (June 20–22, 2001).
(PDF). Proceedings of the 10th International Workshops on Enabling Technologies: Infrastructure for Collaborative Enterprises (WET ICE 01). Massachusetts Institute of Technology, Cambridge, MA, USA. Archived from
(PDF) on January 6, 2006. (118kb)
Preceded&#160;by
Succeeded&#160;by
(currently under formal research & development)
: Hidden categories:}