4G

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This article is about the mobile telecommunications standard. For other uses, see 4G
(disambiguation).
4G stands for the fourth generation of cellular wireless standards. It is a successor to 3G and
2G families of standards. Speed requirements for 4G service set the peak download speed 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).[1]
A 4G system is expected to provide a comprehensive and secure all-IP based mobile
broadband solution to smartphones, laptop computer wireless modems and other mobile
devices. Facilities such as ultra-broadband Internet access, IP telephony, gaming services,
and streamed multimedia may be provided to users.
Pre-4G technologies such as mobile WiMAX and first-release 3G Long term evolution (LTE)
have been on the market since 2006[2] and 2009[3][4][5] respectively, and are often branded as
4G. The current versions of these technologies did not fulfill the original ITU-R requirements
of data rates approximately up to 1 Gbit/s for 4G systems. Marketing materials use 4G as a
description for Mobile-WiMAX and LTE in their current forms.
IMT-Advanced compliant versions of the above two standards are under development and
called “LTE Advanced” and “WirelessMAN-Advanced” respectively. ITU has decided that
“LTE Advanced” and “WirelessMAN-Advanced” should be accorded the official designation
of IMT-Advanced. On December 6, 2010, ITU announced that current versions of LTE,
WiMax and other evolved 3G technologies that do not fulfill "IMT-Advanced" requirements
could be considered "4G", provided they represent forerunners to IMT-Advanced and "a
substantial level of improvement in performance and capabilities with respect to the initial
third generation systems now deployed." [6]
In all suggestions for 4G, the CDMAspread spectrum radio technology used in 3G systems
and IS-95 is abandoned and replaced by OFDMA and other frequency-domain equalization
schemes.[citation needed] This is combined with MIMO (Multiple In Multiple Out), e.g., multiple
antennas, dynamic channel allocation and channel-dependent scheduling.[citation needed]

Contents
[hide]
• 1 Background
• 2 ITU Requirements and 4G wireless standards
• 3 4G Predecessors and candidate systems
○ 3.1 4G candidate systems
 3.1.1 LTE Advanced
 3.1.2 IEEE 802.16m or WirelessMAN-Advanced
○ 3.2 4G predecessors and discontinued candidate systems
 3.2.1 3GPP Long Term Evolution (LTE)
 3.2.2 Mobile WiMAX (IEEE 802.16e)
  3.2.3 UMB (formerly EV-DO Rev. C)
 3.2.4 Flash-OFDM
 3.2.5 iBurst and MBWA (IEEE 802.20) systems
• 4 Data rate comparison
• 5 Objective and approach
○ 5.1 Objectives assumed in the literature
○ 5.2 Approaches
 5.2.1 Principal technologies
• 6 4G features assumed in early literature
• 7 Components
○ 7.1 Access schemes
○ 7.2 IPv6 support
○ 7.3 Advanced antenna systems
○ 7.4 Software-defined radio (SDR)
• 8 History of 4G and pre-4G technologies
○ 8.1 Deployment plans
• 9 Beyond 4G research
• 10 References
○ 10.1 Additional resources

[edit] Background
The nomenclature of the generations generally refers to a change in the fundamental nature of
the service, non-backwards compatible transmission technology, 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, in 2011 expected to be
followed by 4G, which refers to all-IPpacket-switched networks, mobile ultra-broadband
(gigabit speed) access and multi-carrier transmission.[citation needed]
The fastest 3G based standard in the WCDMA family is the HSPA+ standard, which was
commercially available in 2009 and offers 28 Mbit/s downstreams without MIMO, i.e. only
with one antenna (it would offer 56 Mbit/s with 2x2 MIMO), and 22 Mbit/s upstreams. The
fastest 3G based standard in the CDMA2000 family is the EV-DO Rev. B, which was
available in 2010 and offers 15.67 Mbit/s downstreams.[citation needed]
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
IMT-Advanced (International Mobile Telecommunications Advanced) requirements for 4G
systems.
[edit] ITU Requirements and 4G wireless standards
This article uses 4G to refer to IMT-Advanced (International Mobile Telecommunications
Advanced), as defined by ITU-R. An IMT-Advanced cellular system must fulfil the following
requirements:[7]
• Based on an all-IP packet switched network.
• 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, according to the ITU requirements.
• Dynamically share and utilize the network resources to support more simultaneous
users per cell.
• Scalable channel bandwidth, between 5 and 20 MHz, optionally up to 40 MHz.[8][8][9]
• Peak link spectral efficiency of 15 bit/s/Hz in the downlink, and 6.75 bit/s/Hz in the
uplink (meaning that 1 Gbit/s in the downlink should be possible over less than
67 MHz bandwidth)
• System spectral efficiency of up to 3 bit/s/Hz/cell in the downlink and 2.25
bit/s/Hz/cell for indoor usage[8]
• Smooth handovers across heterogeneous networks.
• Ability to offer high quality of service for next generation multimedia support.
In September 2009, the technology proposals were submitted to the International
Telecommunication Union (ITU) as 4G candidates.[10] Basically all proposals are based on
two technologies:
• LTE Advanced standardized by the 3GPP
• 802.16m standardized by the IEEE (i.e. WiMAX)
Present implementations of WiMAX and LTE are largely considered a stopgap solution that
will offer a considerable boost while WiMAX 2 (based on the 802.16m spec) and LTE
Advanced are finalized. Both technologies aim to reach the objectives traced by the ITU, but
are still far from being implemented.[7]
The first set of 3GPP requirements on LTE Advanced was approved in June 2008.[11] LTE
Advanced will be standardized in 2010 as part of the Release 10 of the 3GPP specification.
LTE Advanced will be fully built on the existing LTE specification Release 10 and 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.[12]
Current LTE and WiMAX implementations are considered pre-4G, as they don't fully comply
with the planned requirements of 1 Gbit/s for stationary reception and 100 Mbit/s for mobile.
Confusion has often been caused by some mobile carriers who have launched products
advertised as 4G but which are actually current so-called 3.9G technologies, and therefore do
not follow the ITU-R defined principles for 4G standards. A common argument for branding
3.9G systems as a new generation is that they use other frequency bands than 3G
technologies, they are based on a new radio-interface paradigm, and the standards are not
backwards compatible with 3G but some of them are expected to be forwards compatible
with future "real" 4G technologies. While the ITU has adopted recommendations for
technologies that would be used for future global communications, they do not actually do
the standardization or development work themselves, instead relying on the work of other
standards bodies such as IEEE, The WiMAX Forum and 3GPP. Recently, ITU-R Working
Party 5D approved two industry-developed technologies (LTE Advanced and WirelessMAN-
Advanced)[13] for inclusion in the ITU’s International Mobile Telecommunications Advanced
(IMT-Advanced program), which is focused on global communication systems that would be
available several years from now.[citation needed] This working party’s objective was not to
comment on today’s 4G being rolled out in the United States and in fact, the Working Party
itself purposely agreed not to tie their IMT-Advanced work to the term 4G, recognizing its
common use in industry already; however, the ITU’s PR department ignored that agreement
and used term 4G anyway when issuing their press release.[citation needed]
The ITU’s purpose is to foster the use of communications globally. The ITU is relied upon by
developing countries, for example, who want to be assured a technology is standardised and
likely to be widely deployed. While the ITU has adopted recommendations for technologies
that would be used for future global communications, they do not actually do the
standardization or development work themselves, instead relying on the work of other
standards bodies such as IEEE, The WiMAX Forum and 3GPP. While the ITU has developed
recommendations on IMT-Advanced, those recommendations are not binding on ITU
member countries.[citation needed]
[edit] 4G Predecessors and candidate systems
The wireless telecommunications industry as a whole has early assumed the term 4G as a
short hand way to describe those advanced cellular technologies that, among other things, are
based on or employ wide channel OFDMA and SC-FDE technologies, MIMO transmission
and an all-IP based architecture.[citation needed] Mobile-WiMAX, first release LTE, IEEE 802.20
as well as Flash-OFDM meets these early assumptions, and have been considered as 4G
candidate systems, but do not yet meet the more recent ITU-R IMT-Advanced requirements.
[edit] 4G candidate systems
[edit] LTE Advanced
See also: 3GPP Long Term Evolution (LTE) below
LTE Advanced (Long-term-evolution Advanced) is a candidate for IMT-Advanced standard,
formally submitted by the 3GPP organization to ITU-T in the fall 2009, and expected to be
released in 2012. The target of 3GPP LTE Advanced is to reach and surpass the ITU
requirements.[14] 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 spectrum 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 LTE Advanced
speeds. Release 8 currently supports up to 300 Mbit/s download speeds which is still short of
the IMT-Advanced standards.[15]
Data speeds of LTE Advanced
LTE Advanced
Peak Download 1 Gbit/s
Peak Upload 500 Mbit/s
[edit] IEEE 802.16m or WirelessMAN-Advanced
The IEEE 802.16m or WirelessMAN-Advanced 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.[16]
[edit] 4G predecessors and discontinued candidate systems
[edit] 3GPP Long Term Evolution (LTE)
See also: LTE Advanced above
Telia-branded Samsung LTE modem
The pre-4G technology 3GPP Long Term Evolution (LTE) is often branded "4G", but the
first LTE release does not fully comply with the IMT-Advanced requirements. LTE has a
theoretical net bit rate 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 multiple-input multiple-output (MIMO),
i.e. antenna arrays, are used.
The physical radio interface was at an early stage named High Speed OFDM Packet Access
(HSOPA), now named Evolved UMTS Terrestrial Radio Access (E-UTRA). The first LTE
USB dongles do not support any other radio interface.
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.[3] Currently, the only
publicly available LTE service in the United States is provided by Verizon Wireless[citation
needed]
. AT&T also has an LTE service in the works.[citation needed]
[edit] Mobile WiMAX (IEEE 802.16e)
The Mobile WiMAX (IEEE 802.16e-2005) mobile wireless broadband access (MWBA)
standard (also known as WiBro 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[citation
needed]
.
The world's first commercial mobile WiMAX service was opened by KT in Seoul, South
Korea on 30 June 2006.[2]
Sprint Nextel has begun using Mobile WiMAX, as of September 29, 2008 branded as a "4G"
network even though the current version does not fulfil the IMT Advanced requirements on
4G systems.[17]
In Russia, Belarus and Nicaragua WiMax broadband internet access is offered by a Russian
company Scartel, and is also branded 4G, Yota.
[edit] UMB (formerly EV-DO Rev. C)
Main article: Ultra Mobile Broadband
UMB (Ultra Mobile Broadband) was the brand name for a discontinued 4G project within the
3GPP2 standardization group to improve the CDMA2000 mobile phone standard for next
generation applications and requirements. In November 2008, Qualcomm, UMB's lead
sponsor, announced it was ending development of the technology, favouring LTE instead.[18]
The objective was to achieve data speeds over 275 Mbit/s downstream and over 75 Mbit/s
upstream.
[edit] Flash-OFDM
At an early stage the Flash-OFDM system was expected to be further developed into a 4G
standard.
[edit] iBurst and MBWA (IEEE 802.20) systems
The iBurst system ( or HC-SDMA, High Capacity Spatial Division Multiple Access) was at
an early stage considered as a 4G predecessor. It was later further developed into the Mobile
Broadband Wireless Access (MBWA) system, also known as IEEE 802.20.
[edit] Data rate comparison
The following table shows a comparison of 4G candidate systems as well as other competing
technologies.
Comparison of Mobile Internet Access methods (This box: view·talk·edit)
Downlin
Primary Uplink
k
(Mbit/s)
Standard Family Radio Tech (Mbit/s) Notes
Use

LTE-
Advanced
update
100 (in 50 (in 20 expected to
UMTS/4G OFDMA/MIMO/ 20MHz MHz offer peak
LTE General 4G
SM SC-FDMA bandwidt bandwidt rates up to 1
h) h) Gbit/s fixed
speeds and
100 Mb/s to
mobile users.
WiMAX
update IEEE
802.16m
expected to
128 (in 56 (in
offer peak
Mobile MIMO- 20MHz 20MHz
WiMAX 802.16 rates of at
Internet SOFDMA bandwidt bandwidt
least 1 Gbit/s
h) h)
fixed speeds
and 100Mbit/s
to mobile
users.
Flash-OFDM Flash- Mobile Flash-OFDM 5.3 1.8 Mobile range
OFDM Internet 10.6 3.6 30km (18
mobility up 15.9 5.4 miles)
 extended
to 200mph
range 55 km
(350km/h)
(34 miles)
HIPERMA Mobile
HIPERMAN OFDM 56.9 56.9
N Internet
Antenna, RF
front end
enhancements
and minor
protocol timer
300 (using 4x4
tweaks have
configuration in
helped deploy
20MHz
long range
802.11 Mobile Inter bandwidth) or 600
Wi-Fi OFDM/MIMO P2P networks
(11n) net (using 4x4
compromising
configuration in
on radial
40MHz
coverage,
bandwidth)
throughput
and/or spectra
efficiency
(310km&382k
m)
Cell Radius:
3–12 km
Speed:
250km/h
HC-
Mobile Inter Spectral
iBurst 802.20 SDMA/TDD/MI 95 36
net Efficiency: 13
MO
bits/s/Hz/cell
Spectrum
Reuse Factor:
"1"
EDGE Mobile Inter 3GPP Release
GSM TDMA/FDD 0.2 0.2
Evolution net 7
HSDPA
widely
deployed.
UMTS W- Typical
CDMA/FDD
CDMA 0.384 0.384 downlink rates
UMTS/3G
HSDPA+HSU General 3G 14.4 5.76 today 2
SM CDMA/FDD/MI
PA 56 22 Mbit/s, ~200
MO
HSPA+ kbit/s uplink;
HSPA+
downlink up
to 56 Mbit/s.
UMTS-TDD UMTS/3G Mobile CDMA/TDD 16 16 Reported
SM Internet speeds
according to
IPWireless
using 16QAM
 modulation
similar to
HSDPA+HSU
PA
Succeeded by
EV-DO for
data use, but
CDMA200 Mobile
1xRTT CDMA 0.144 0.144 still is used for
0 phone
voice and as a
failover for
EV-DO
Rev B note: N
is the number
of 1.25 MHz
chunks of
spectrum used.
EV-DO 1x Re
EV-DO is not
v. 0 2.45 0.15
CDMA200 Mobile designed for
EV-DO 1x Re CDMA/FDD 3.1 1.8
0 Internet voice, and
v.A 4.9xN 1.8xN
requires a
EV-DO Rev.B
fallback to
1xRTT when a
voice call is
placed or
received.
Notes: All speeds are theoretical maximums and will vary by a number of factors, including
the use of external antennae, distance from the tower and the ground speed (e.g.
communications on a train may be poorer than when standing still). Usually the bandwidth is
shared between several terminals. The performance of each technology is determined by a
number of constraints, including the spectral efficiency of the technology, the cell sizes used,
and the amount of spectrum available. For more information, see Comparison of wireless
data standards.
For more comparison tables, see bit rate progess trends, comparison of mobile phone
standards, spectral efficiency comparison table and OFDM system comparison table.
[edit] Objective and approach
[edit] Objectives assumed in the literature
4G is being developed to accommodate the quality of service (QoS) and rate requirements set
by further development of existing 3G applications like mobile broadband access,
Multimedia Messaging Service (MMS), video chat, mobile TV, but also new services like
HDTV. 4G may allow roaming with wireless local area networks, and may interact with
digital video broadcasting systems.
In the literature, the assumed or expected 4G requirements have changed during the years
before IMT-Advanced was specified by the ITU-R. These are examples of objectives stated
in various sources:
• A nominal data rate of 100 Mbit/s while the client physically moves at high speeds
relative to the station, and 1 Gbit/s while client and station are in relatively fixed
positions as defined by the ITU-R[19]
• A data rate of at least 100 Mbit/s between any two points in the world[19]
 • Smooth handoff across heterogeneous networks[20]
• Seamless connectivity and global roaming across multiple networks[21]
• High quality of service for next generation multimedia support (real time audio, high
speed data, HDTV video content, mobile TV, etc.)[21]
• Interoperability with existing wireless standards[22]
• An all IP, packet switched network[21]
• IP-based femtocells (home nodes connected to fixed Internet broadband
infrastructure)
[edit] Approaches
[edit] Principal technologies
• Physical layer transmission techniques are as follows:[23]
○ MIMO: 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
(OFDM) 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 (OFDMA) 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
○ Turbo principleerror-correcting codes: To minimize the required SNR at the
reception side
• Channel-dependent scheduling: To utilize the time-varying channel.
• Link adaptation: Adaptive modulation and error-correcting codes
• Relaying, including fixed relay networks (FRNs), and the cooperative relaying
concept, known as multi-mode protocol
[edit] 4G features assumed in early literature
The 4G system was originally envisioned by the Defense Advanced Research Projects
Agency (DARPA).[citation needed] 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.[24] 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.
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 acessing fixed wireless networks.[25]
While maintaining seamless mobility, 4G will offer very high data rates with expectations of
100 Mbit/s wireless service. The increased bandwidth and higher data transmission rates will
allow 4G users the ability to utilize high definition video and the video conferencing features
of mobile devices attached to a 4G network. The 4G wireless system is expected to provide a
comprehensive IP solution where multimedia applications and services can be delivered to
the user on an ‘Anytime, Anywhere' basis with a satisfactory high data rate, premium quality
and high security.[26]
4G is described as MAGIC — Mobile multimedia, Anytime anywhere, Global mobility
support, Integrated wireless solution, and Customized personal service.
Some key features (primarily from users' points of view) of 4G mobile networks are as
follows:
• High usability: anytime, anywhere, and with any technology
• Support for multimedia services at low transmission cost
• Personalization
• Integrated services
Some candidate systems suggest having an open Internet platform.
[edit] Components
[edit] Access schemes
This section contains information which may be of unclear or questionable
importance or relevance to the article's subject matter.
Please help improve this article by clarifying or removing superfluous information. (May 2010)

As the wireless standards evolved, the access techniques used also exhibited increase in
efficiency, capacity and scalability. The first generation wireless standards used plain TDMA
and FDMA. In the wireless channels, TDMA proved to be less efficient in handling the high
data rate channels as it requires large guard periods to alleviate the multipath impact.
Similarly, FDMA consumed more bandwidth for guard to avoid inter carrier interference. So
in second generation systems, one set of standard used the combination of FDMA and
TDMA and the other set introduced an access scheme called CDMA. Usage of CDMA
increased the system capacity, but as a theoretical drawback placed a soft limit on it rather
than the hard limit (i.e. a CDMA network setup does not inherently reject new clients when it
approaches its limits, resulting in a denial of service to all clients when the network
overloads; though this outcome is avoided in practical implementations by admission control
of circuit switched or fixed bitrate communication services). Data rate is also increased as
this access scheme (providing the network is not reaching its capacity) is efficient enough to
handle the multipath channel. This enabled the third generation systems, such as IS-2000,
UMTS, HSXPA, 1xEV-DO, TD-CDMA and TD-SCDMA, to use CDMA as the access
scheme. However, the issue with CDMA is that it suffers from poor spectral flexibility and
computationally intensive time-domain equalization (high number of multiplications per
second) for wideband channels.
Recently, new access schemes like Orthogonal FDMA (OFDMA), Single Carrier FDMA
(SC-FDMA), Interleaved FDMA and Multi-carrier CDMA (MC-CDMA) are gaining more
importance for the next generation systems. These are based on efficient FFT 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 traffic adaptive scheduling.
WiMax is using OFDMA in the downlink and in the uplink. For the next generation UMTS,
OFDMA is used for the downlink. By contrast, IFDMA is being considered for the uplink
since OFDMA contributes more to the PAPR related issues and results in nonlinear operation
of amplifiers. IFDMA provides less power fluctuation and thus avoids amplifier issues.
Similarly, MC-CDMA is in the proposal for the IEEE 802.20 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
MIMO environments since the spatial multiplexing transmission of MIMO systems
inherently requires high complexity equalization at the receiver.
In addition to improvements in these multiplexing systems, improved modulation techniques
are being used. Whereas earlier standards largely used Phase-shift keying, more efficient
systems such as 64QAM are being proposed for use with the 3GPP Long Term Evolution
standards.
[edit] IPv6 support
Main articles: Network layer, Internet protocol, and IPv6
Unlike 3G, which is based on two parallel infrastructures consisting of circuit switched and
packet switched network nodes respectively, 4G will be based on packet switching only. This
will require low-latency data transmission.
By the time that 4G is deployed, the process of IPv4 address exhaustion is expected to be in
its final stages. Therefore, in the context of 4G, IPv6 support is essential in order to support a
large number of wireless-enabled devices. By increasing the number of IP addresses, IPv6
removes the need for network address translation (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 IPv4 networks.
As of June 2009[update], Verizon has posted specifications that require any 4G devices on its
network to support IPv6.[27]
[edit] Advanced antenna systems
Main articles: MIMO and MU-MIMO
The performance of radio communications depends on an antenna system, termed smart or
intelligent antenna. Recently, multiple antenna technologies 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, spatial multiplexing, 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 MIMO (as a branch
of intelligent antenna), 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.
[edit] Software-defined radio (SDR)
SDR 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.
[edit] History of 4G and pre-4G technologies
• 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.
[28]

• In June 2006, KT started the world's first commercial mobile WiMAX service in
Seoul, South Korea.[2]
• In mid-2006, Sprint Nextel announced that it would invest about US$5 billion in a
WiMAX technology buildout over the next few years[29] ($5.45 billion in real
terms[30]). 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 XohmWiMAX division with Clearwire to form a
company which will take the name "Clear".
• In February 2007, the Japanese companyNTT 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,[31]
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.[32]
• 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.[33]
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.[34]
• February 15, 2008 - Skyworks Solutions released a front-end module for e-UTRAN.
[35][36][37]

• In April 2008, LG and Nortel demonstrated e-UTRA data rates of 50 Mbit/s while
travelling at 110 km/h.[38]
• 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.[39]
 • 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.
• On 3 March 2009, Lithuania's LRTC announcing the first operational "4G" mobile
WiMAX network in Baltic states.[40]
• 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).[41]
• On December 14, 2009, the first commercial LTE deployment was in the
Scandinavian capitals Stockholm and Oslo by the Swedish-Finnish network operator
TeliaSonera and its Norwegian brandnameNetCom (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.[4][42]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
TCPthroughput of 42.8 Mbit/s downlink and 5.3 Mbit/s uplink in Stockholm.[5]
• On 25 February 2010, Estonia's EMT opened LTE "4G" network working in test
regime.[43]
• On 4 June 2010, Sprint Nextel released the first 4G Smartphone, the HTC Evo 4G.
• On July 2010, Uzbekistan's MTS deployed LTE in Tashkent.[44]
• 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".[6]
• On 12 December 2010, VivaCell-MTS launches in Armenia 4G/LTE commercial test
network with a live demo conducted in Yerevan.[45]
[edit] Deployment plans
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.[46][47]Digiweb launched a mobile broadband network using
FLASH-OFDM technology at 872 MHz.
On September 20, 2007, Verizon Wireless announced plans for a joint effort with the
Vodafone Group to transition its networks to the 4G standard LTE. On December 9, 2008,
Verizon Wireless announced their intentions to build and begin to roll out an LTE network by
the end of 2009. Since then, Verizon Wireless has said that they will start their rollout by the
end of 2010.
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.[48]
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.[49]
Sprint offers a 3G/4G connection plan, currently available in select cities in the United States.
[41]
It delivers rates up to 10 Mbit/s.
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.[50]
Verizon Wireless has announced that it plans to augment its CDMA2000-based EV-DO 3G
network in the United States with LTE. AT&T, along with Verizon Wireless, has chosen to
migrate toward LTE from 2G/GSM and 3G/HSPA by 2011.[51]
Sprint Nextel has deployed WiMAX technology which it has labeled 4G as of October 2008.
It is currently deploying to additional markets and is the first US carrier to offer a WiMAX
phone.[52]
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.[53]
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.[54]
Safaricom, a telecommunication company in East& Central Africa, began it's 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
[edit] Beyond 4G research
Main article: 5G
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 basestations. In current
research, this issue is addressed by macro-diversity techniques, also known as group
cooperative relay, and also by beam-division multiple access.[55]
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.
.
[edit] References
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2. ^ abc"South Korea launches WiBro service". EE Times. 2006-06-30.
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http://online.wsj.com/article/BT-CO-20091214-707449.html. [dead link]
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8. ^ abcITU-R, Report M.2134, Requirements related to technical performance for IMT-
Advanced radio interface(s), Approved in Nov 2008
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Measurement Journal, September 2008
10.^Nomor Research Newsletter: The way of LTE towards 4G
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12.^3GPP Technical Report: Feasibility study for Further Advancements for E-UTRA (LTE
Advanced)
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Wänstedt, Stefan; Zangi, Kambiz (21–24 September 2008). "LTE Advanced – Evolving LTE
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17.^"Sprint announces seven new WiMAX markets, says 'Let AT&T and Verizon yak about
maps and 3G coverage'". Engadget. 2010-03-23.
http://www.engadget.com/2010/03/23/sprint-announces-seven-new-wimax-markets-says-let-
atandt-and-ver/. Retrieved 2010-04-08.
18.^Qualcomm halts UMB project, Reuters, November 13th, 2008
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Technologies. Artech House 2006. pp. 12–13. ISBN 1-58053-931-9.
20.^SadiaHussain, Zara Hamid and Naveed S. Khattak (May 30–31, 2006). "Mobility
Management Challenges and Issues in 4G Heterogeneous Networks". ACM Proceedings of
the first international conference on Integrated internet ad hoc and sensor networks.
http://delivery.acm.org/10.1145/1150000/1142698/a14-hussain.pdf?
key1=1142698&key2=8898704611&coll=GUIDE&dl=&CFID=15151515&CFTOKEN=618
4618. Retrieved 2007-03-26.
21.^ abc Werner Mohr (2002). "Mobile Communications Beyond 3G in the Global Context"
(PDF). Siemens mobile. http://www.cu.ipv6tf.org/pdf/werner_mohr.pdf. Retrieved 2007-03-
26.
22.^ Noah Schmitz (March 2005). "The Path To 4G Will Take Many Turns". Wireless Systems
Design. http://www.wsdmag.com/Articles/ArticleID/10001/10001.html. Retrieved 2007-03-
26.
23.^ G. Fettweis, E. Zimmermann, H. Bonneville, W. Schott, K. Gosse, M. de Courville (2004).
"High Throughput WLAN/WPAN" (PDF). WWRF. http://www.wireless-world-
research.org/fileadmin/sites/default/files/about_the_forum/WG/WG5/Briefings/WG5-br2-
High_Throughput_WLAN_WPAN-V2004.pdf.
24.^Zheng, P., Peterson, L., Davie, B., &Farrel, A. (2009). Wireless Networking Complete.
Morgan Kaufmann
25.^Nicopolitidis, P. (2003). WIRELESS NETWORKS (p. 190). Chichester, England ;
Hoboken, NJ : John Wiley & Sons, Ltd. (UK), 2003
26.^ Mishra, A. R. (2007). In Advanced Cellular Network Planning and Optimisation:
2G/2.5G/3G...Evolution to 4G. The Atrium, Southern Gate, Chichester, West Sussex PO19
8SQ, England: John Wiley & Sons.
27.^Morr, Derek (2009-06-09). "Verizon mandates IPv6 support for next-gen cell phones".
http://www.personal.psu.edu/dvm105/blogs/ipv6/2009/06/verizon-mandates-ipv6-
support.html. Retrieved 2009-06-10.
28.^"KT Launches Commercial WiBro Services in Korea". WiMAX Forum. 2005-11-15.
http://www.wimaxforum.org/news/831. Retrieved 2010-06-23.
29.^"4G Mobile Broadband". sprint.com. http://www2.sprint.com/mr/cda_pkDetail.do?id=1260.
Retrieved 2008-03-12.
30.^Consumer Price Index (estimate) 1800–2008. Federal Reserve Bank of Minneapolis.
Retrieved December 7, 2010.
31.^"DoCoMo Achieves 5 Gbit/s Data Speed". NTT DoCoMo Press. 2007-02-09.
http://www.nttdocomo.com/pr/2007/001319.html.
32.^ Reynolds, Melanie (2007-09-14). "NTT DoCoMo develops low power chip for 3G LTE
handsets". Electronics Weekly.
http://www.electronicsweekly.com/Articles/2007/09/14/42179/ntt-docomo-develops-low-
power-chip-for-3g-lte-handsets.htm. Retrieved 2010-04-08.
33.^"Auctions Schedule". FCC. http://wireless.fcc.gov/auctions/default.htm?
job=auctions_sched. Retrieved 2008-01-08.
34.^"European Commission proposes TV spectrum for WiMax". zdnetasia.com.
http://www.zdnetasia.com/news/communications/0,39044192,62021021,00.htm. Retrieved
2008-01-08.
35.^"Skyworks Rolls Out Front-End Module for 3.9G Wireless Applications. (Skyworks
Solutions Inc.)". Wireless News. February 14, 2008.
http://www.accessmylibrary.com/coms2/summary_0286-33896688_ITM. Retrieved 2008-09-
14.
36.^"Wireless News Briefs — February 15, 2008". WirelessWeek. February 15, 2008.
http://www.wirelessweek.com/News_Briefs021508.aspx. Retrieved 2008-09-14.
37.^"Skyworks Introduces Industry's First Front-End Module for 3.9G Wireless
Applications.".Skyworks press release (Free with registration). 11 FEB 2008.
http://www.accessmylibrary.com/coms2/summary_0286-33869434_ITM. Retrieved 2008-09-
14.
38.^Nortel and LG Electronics Demo LTE at CTIA and with High Vehicle Speeds :: Wireless-
Watch Community
 39.^ ITU-R Report M.2134, “Requirements related to technical performance for IMT-Advanced
radio interface(s),” November 2008.
40.^WiMAX Forum (3 March 2009). "LRTC to Launch Lithuania’s First Mobile WiMAX 4G
Internet Service". Press release. http://www.wimaxforum.org/news/837. Retrieved 26
November 2010.
41.^ ab"4G Coverage and Speeds". Sprint.
http://nextelonline.nextel.com/en/stores/popups/4G_coverage_popup.shtml. Retrieved 26
November 2010.
42.^NetCom.no - NetCom 4G (in English)
43.^Neudorf, Raigo (25 February 2010). "EMT avas 4G testvõrgu". E24.ee. http://www.e24.ee/?
id=229584. Retrieved 26 November 2010.
44.^МТS kompaniyasiO’zbekistonda 4G tarmog’iishgatushirilishinie’lonqiladi (in Uzbek)
45.^VivaCell-MTS launches in Armenia 4G/LTE
46.^ Press Release: Digiweb Mobile Takes 088
47.^ RTÉ News article: Ireland gets new mobile phone provider
48.^"Korea to Begin Developing 5G". unwiredview.com. 2008-07-08.
http://www.unwiredview.com/2008/07/08/korea-to-start-working-on-5g/. Retrieved 2010-04-
08.
49.^ TELUS (2008-10-10). "Next Generation Network Evolution". TELUS.
http://www.telusmobility.com/network/.
50.^Neate, Rupert (2009-12-12). "Slough accepts the call to be 4G mobile phone trailblazer".
The Daily Telegraph (London).
http://www.telegraph.co.uk/finance/newsbysector/mediatechnologyandtelecoms/6797198/Slo
ugh-accepts-the-call-to-be-4G-mobile-phone-trailblazer.html. Retrieved 2010-04-08.
51.^"AT&T, Verizon, Vodafone to share same 4G network". Electronista. 2007-09-21.
http://www.electronista.com/articles/07/09/21/verizon.and.vodafone.4g/. Retrieved 2010-04-
08.
52.^Sprint (23 March 2010). "World's First 3G/4G Android Phone, HTC EVO™ 4G, Coming
this Summer Exclusively from Sprint". Press release.
http://newsroom.sprint.com/article_display.cfm?article_id=1414. Retrieved 26 November
2010.
53.^ FCC White Paper. "The Public Safety Nationwide Interoperable Broadband Network, A
New Model For Capacity, Performance and Cost", June 2010.
54.^TeliaSonera website
55.^ IT R&D program of MKE/IITA: 2008-F-004-01 “5G mobile communication systems based
on beam-division multiple access and relays with group cooperation”.
[edit] Additional resources
• 3GPP LTE Encyclopedia
• Alcatel-Lucent chair on Flexible Radio, working on the concept of small cells
• Nomor Research: White Paper on LTE Advance the new 4G standard
• Brian Woerner (June 20–22, 2001). "Research Directions for Fourth Generation
Wireless" (PDF). Proceedings of the 10th International Workshops on Enabling
Technologies: Infrastructure for Collaborative Enterprises (WET ICE ’01) .
Massachusetts Institute of Technology, Cambridge, MA, USA.
http://csdl2.computer.org/comp/proceedings/wetice/2001/1269/00/12690060.pdf.
(118kb)
 • Sajal Kumar Das, John Wiley & Sons (April 2010): "Mobile Handset Design", ISBN
978-0470824672
• Suk Yu Hui; Kai HauYeung (December 2003). "Challenges in the migration to 4G
mobile systems". Communications Magazine, IEEE (City Univ. of Hong Kong,
China) 41: 54. doi:10.1109/MCOM.2003.1252799.
http://ieeexplore.ieee.org/xpls/abs_all.jsp?arnumber=1252799&isnumber=28028.
• "4G Mobile". Alcatel-Lucent. 2005-06-13.
http://www.alcatel.com/publications/abstract.jhtml?repositoryItem=tcm%3A172-
262211635.
• Will Knight (2005-09-02). "4G prototype testing". New Scientist.
http://www.newscientist.com/article.ns?id=dn7943.
• "Caribbean telecoms to invest in 4G wireless networks". Caribbean Net News. 2006-
06-27. http://www.caribbeannetnews.com/cgi-
script/csArticles/articles/000021/002142.htm.
• "High speed mobile network to launch in Jersey". BBC News. 2010-03-19.
http://news.bbc.co.uk/local/jersey/hi/people_and_places/arts_and_culture/newsid_857
4000/8574436.stm.
• "Future use of 4G Femtocells". 2010-03-10. http://www.ict-befemto.eu/.
• "Date set for 4G airwaves auction". 2010-11-17.
http://www.bbc.co.uk/news/technology-11776901/.
• "4G service". 2010-12-17. http://4gservice.org.

Preceded by Succeeded by
Mobile Telephony Generations
3rd Generation (3G) 5th Generation (5G)

[hide]v·d·eMobile telephony standards

0G (radio MTS ·MTA · MTB ·

telephones) MTC ·IMTS ·MTD ·AMTS ·OLT ·Autoradiopuhelin

AMPS
AMPS ·TACS ·ETACS
family
1G
OtherNMT ·Hicap ·Mobitex ·DataTAC

GSM/3GPP
GSM ·CSD
family

3GPP2 familyCdmaOne (IS-95)

2G
AMPS familyD-AMPS (IS-54 and IS-136)

OtherCDPD ·iDEN ·PDC ·PHS

2G transitional GSM/3GPP
(2.5G, 2.75G) HSCSD ·GPRS ·EDGE/EGPRS
family
 3GPP2 familyCDMA2000 1xRTT (IS-2000)

OtherWiDEN

UMTS (UTRAN) ·WCDMA-FDD ·WCDMA-

3GPP family
TDD ·UTRA-TDD LCR (TD-SCDMA)
3G (IMT-2000)
3GPP2
CDMA2000 1xEV-DO (IS-856)
family

3GPP familyHSPA ·HSPA+ ·LTE (E-UTRA)

3GPP2
3G transitional EV-DO Rev. A ·EV-DO Rev. B
family
(3.5G, 3.75G, 3.9G)
Mobile WiMAX (IEEE 802.16e-2005) ·Flash-
Other
OFDM ·IEEE 802.20

3GPP familyLTE Advanced

4G (IMT-Advanced)
WiMAX
IEEE 802.16m
family

unconfirme
5G unconfirmed
d

History ·Cellular network theory ·List of standards ·Comparison

of standards ·Channel access methods ·Spectral efficiency
Related articles
comparison table ·Cellular frequencies ·GSM frequency
bands ·UMTS frequency bands ·Mobile broadband
Retrieved from "http://en.wikipedia.org/wiki/4G"
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