LTE Advanced (LTE+) is a mobile communication standard and a major enhancement of the
Long Term Evolution
In telecommunications, long-term evolution (LTE) is a standard for wireless broadband communication for mobile devices and data terminals, based on the GSM/EDGE and UMTS/HSPA standards. It improves on those standards' capacity and speed by us ...
(LTE) standard. It was formally submitted as a candidate
4G to
ITU-T
The ITU Telecommunication Standardization Sector (ITU-T) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU). It is responsible for coordinating standards for telecommunications and Information Comm ...
in late 2009 as meeting the requirements of the
IMT-Advanced
International Mobile Telecommunications-Advanced (IMT-Advanced Standard) are the requirements issued by the ITU Radiocommunication Sector (ITU-R) of the International Telecommunication Union (ITU) in 2008 for what is marketed as 4G (or in Turke ...
standard, and was standardized by the 3rd Generation Partnership Project (
3GPP) in March 2011 as 3GPP Release 10.
The LTE+ format was first proposed by
NTT DoCoMo of
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
and has been adopted as the international standard. LTE standardization has matured to a state where changes in the specification are limited to corrections and
bug fix
A patch is a set of changes to a computer program or its supporting data designed to update, fix, or improve it. This includes fixing security vulnerabilities and other bugs, with such patches usually being called bugfixes or bug fixes. Patche ...
es. The first commercial services were launched in
Sweden
Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...
and
Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...
in December 2009
followed by the United States and Japan in 2010. More LTE networks were deployed globally during 2010 as a natural evolution of several 2G and 3G systems, including
Global system for mobile communications
The Global System for Mobile Communications (GSM) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile devices such as ...
(GSM) and
Universal Mobile Telecommunications System
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP (3rd Generation Partnership Project), UMTS is a component of the In ...
(UMTS) in the
3GPP family as well as
CDMA2000 in the
3GPP2 family.
The work by
3GPP to define a
4G candidate radio interface technology started in Release 9 with the study phase for LTE-Advanced. Being described as a
3.9G (beyond 3G but pre-4G), the first release of LTE did not meet the requirements for
4G (also called
IMT Advanced
International Mobile Telecommunications-Advanced (IMT-Advanced Standard) are the requirements issued by the ITU Radiocommunication Sector (ITU-R) of the International Telecommunication Union (ITU) in 2008 for what is marketed as 4G (or in Turke ...
as defined by the
International Telecommunication Union
The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
) such as peak data rates up to 1
Gb/s
In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multi ...
. The ITU has invited the submission of candidate Radio Interface Technologies (RITs) following their requirements in a circular letter, 3GPP Technical Report (TR) 36.913, "Requirements for Further Advancements for
E-UTRA
E-UTRA is the air interface of 3rd Generation Partnership Project ( 3GPP) Long Term Evolution (LTE) upgrade path for mobile networks. It is an acronym for Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access, also r ...
(LTE-Advanced)." These are based on ITU's requirements for
4G and on operators’ own requirements for advanced LTE.
Major technical considerations include the following:
* Continual improvement to the LTE radio technology and architecture
* Scenarios and performance requirements for working with legacy radio technologies
* Backward compatibility of LTE-Advanced with LTE. An LTE terminal should be able to work in an LTE-Advanced network and vice versa. Any exceptions will be considered by
3GPP.
* Consideration of recent
World Radiocommunication Conference
The World Radiocommunication Conference (WRC) is a conference organized by the ITU to review and, as necessary, revise the Radio Regulations, the international treaty governing the use of the radio-frequency spectrum as well as geostationary and ...
(WRC-07) decisions regarding frequency bands to ensure that LTE-Advanced accommodates the geographically available spectrum for channels above 20 MHz. Also, specifications must recognize those parts of the world in which wideband channels are not available.
Likewise, '
WiMAX 2
Worldwide Interoperability for Microwave Access (WiMAX) is a family of wireless broadband communication standards based on the IEEE 802.16 set of standards, which provide physical layer (PHY) and media access control (MAC) options.
The WiMAX ...
', 802.16m, has been approved by ITU as the
IMT Advanced
International Mobile Telecommunications-Advanced (IMT-Advanced Standard) are the requirements issued by the ITU Radiocommunication Sector (ITU-R) of the International Telecommunication Union (ITU) in 2008 for what is marketed as 4G (or in Turke ...
family. WiMAX 2 is designed to be backward compatible with WiMAX 1 devices. Most vendors now support conversion of 'pre-4G', pre-advanced versions and some support software upgrades of base station equipment from 3G.
The mobile communication industry and standards organizations have therefore started work on 4G access technologies, such as LTE Advanced. At a workshop in April 2008 in China, 3GPP agreed the plans for work on Long Term Evolution (LTE). A first set of specifications were approved in June 2008. Besides the peak data rate 1
Gb/s
In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols (baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multi ...
as defined by the ITU-R, it also targets faster switching between power states and improved performance at the cell edge. Detailed proposals are being studied within the
working group
A working group, or working party, is a group of experts working together to achieve specified goals. The groups are domain-specific and focus on discussion or activity around a specific subject area. The term can sometimes refer to an interdis ...
s.
Three technologies from the LTE-Advanced tool-kit
carrier aggregation
Carrier aggregation is a technique that is used in wireless communication to increase the data rate per user, whereby multiple frequency blocks (called ''component carriers'') are assigned to the same user. The maximum possible data rate per user i ...
, 4x4
MIMO
In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...
and
256QAM modulation in the downlink if used together and with sufficient aggregated bandwidth, can deliver maximum peak downlink speeds approaching, or even exceeding, 1 Gbit/s. Such networks are often described as ‘Gigabit LTE networks’ mirroring a term that is also used in the fixed broadband industry.
Proposals
The target of 3GPP LTE Advanced is to reach and surpass the
ITU
The International Telecommunication Union is a specialized agency of the United Nations responsible for many matters related to information and communication technologies. It was established on 17 May 1865 as the International Telegraph Unio ...
requirements. LTE Advanced should be compatible with first release LTE equipment, and should share frequency bands with first release LTE. In the feasibility study for LTE Advanced,
3GPP determined that LTE Advanced would meet the
ITU-R
The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communications.
Its role is to manage the international radio-frequency sp ...
requirements for
4G. The results of the study are published in
3GPP Technical Report (TR) 36.912.
One of the important LTE Advanced benefits is the ability to take advantage of advanced topology networks; optimized heterogeneous networks with a mix of macrocells with low power nodes such as
picocell
A picocell is a small cellular base station typically covering a small area, such as in-building (offices, shopping malls, train stations, stock exchanges, etc.), or more recently in-aircraft. In cellular networks, picocells are typically used to e ...
s,
femtocell
In telecommunications, a femtocell is a small, low-power cellular base station, typically designed for use in a home or small business. A broader term which is more widespread in the industry is '' small cell'', with ''femtocell'' as a subset. It ...
s and new relay nodes. The next significant performance leap in wireless networks will come from making the most of topology, and brings the network closer to the user by adding many of these low power nodes LTE Advanced further improves the capacity and coverage, and ensures user fairness. LTE Advanced also introduces multicarrier to be able to use ultra wide bandwidth, up to 100 MHz of spectrum supporting very high data rates.
In the research phase many proposals have been studied as candidates for LTE Advanced (LTE-A) technologies. The proposals could roughly be categorized into:
* Support for relay node base stations
* Coordinated multipoint (CoMP) transmission and reception
* UE Dual TX antenna solutions for
SU-MIMO
In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...
and diversity
MIMO
In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...
, commonly referred to as 2x2 MIMO
* Scalable system
bandwidth
Bandwidth commonly refers to:
* Bandwidth (signal processing) or ''analog bandwidth'', ''frequency bandwidth'', or ''radio bandwidth'', a measure of the width of a frequency range
* Bandwidth (computing), the rate of data transfer, bit rate or thr ...
exceeding 20 MHz, up to 100 MHz
*
Carrier aggregation
Carrier aggregation is a technique that is used in wireless communication to increase the data rate per user, whereby multiple frequency blocks (called ''component carriers'') are assigned to the same user. The maximum possible data rate per user i ...
of contiguous and non-contiguous spectrum allocations
* Local area optimization of
air interface
The air interface, or access mode, is the communication link between the two stations in mobile or wireless communication. The air interface involves both the physical and data link layers (layer 1 and 2) of the OSI model for a connection.
Physi ...
* Nomadic / Local Area network and mobility solutions
* Flexible
spectrum usage
*
Cognitive radio
A cognitive radio (CR) is a radio that can be programmed and configured dynamically to use the best wireless channels in its vicinity to avoid user interference and congestion. Such a radio automatically detects available channels in wireless spec ...
* Automatic and autonomous network configuration and operation
* Support of autonomous network and device test, measurement tied to network management and optimization
* Enhanced
precoding
Precoding is a generalization of beamforming to support multi-stream (or multi-layer) transmission in multi-antenna wireless communications. In conventional single-stream beamforming, the same signal is emitted from each of the transmit antennas ...
and
forward error correction
* Interference management and suppression
* Asymmetric bandwidth assignment for
FDD
* Hybrid
OFDMA
Orthogonal frequency-division multiple access (OFDMA) is a multi-user version of the popular orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to ...
and
SC-FDMA
Single-carrier FDMA (SC-FDMA) is a frequency-division multiple access scheme. It is also called linearly precoded OFDMA (LP-OFDMA). Like other multiple access schemes (TDMA, FDMA, CDMA, OFDMA), it deals with the assignment of multiple users to a ...
in uplink
* UL/DL inter
eNB coordinated MIMO
*
SONs
A son is a male offspring; a boy or a man in relation to his parents. The female counterpart is a daughter. From a biological perspective, a son constitutes a first degree relative.
Social issues
In pre-industrial societies and some current ...
, Self Organizing Networks methodologies
Within the range of system development, LTE-Advanced and WiMAX 2 can use up to 8x8
MIMO
In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...
and 128-
QAM
Quadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. It conveys two analog message signa ...
in downlink direction. Example performance: 100 MHz aggregated bandwidth, LTE-Advanced provides almost 3.3 Gbit peak download rates per sector of the base station under ideal conditions. Advanced network architectures combined with distributed and collaborative smart antenna technologies provide several years road map of commercial enhancements.
The
3GPP standards Release 12 added support for 256-QAM.
A summary of a study carried out in 3GPP can be found in TR36.912.
Timeframe and introduction of additional features
Original standardization work for LTE-Advanced was done as part of 3GPP Release 10, which was frozen in April 2011. Trials were based on pre-release equipment. Major vendors support software upgrades to later versions and ongoing improvements.
In order to improve the quality of service for users in hotspots and on cell edges,
heterogenous networks (HetNet) are formed of a mixture of macro-, pico- and femto base stations serving corresponding-size areas. Frozen in December 2012, 3GPP Release 11 concentrates on better support of HetNet. Coordinated Multi-Point operation (CoMP) is a key feature of Release 11 in order to support such network structures. Whereas users located at a cell edge in homogenous networks suffer from decreasing signal strength compounded by neighbor cell interference, CoMP is designed to enable use of a neighboring cell to also transmit the same signal as the serving cell, enhancing quality of service on the perimeter of a serving cell. In-device Co-existence (IDC) is another topic addressed in Release 11. IDC features are designed to ameliorate disturbances within the user equipment caused between LTE/LTE-A and the various other radio subsystems such as WiFi, Bluetooth, and the GPS receiver. Further enhancements for MIMO such as 4x4 configuration for the uplink were standardized.
The higher number of cells in HetNet results in user equipment changing the serving cell more frequently when in motion.
The ongoing work on LTE-Advanced in Release 12, amongst other areas, concentrates on addressing issues that come about when users move through HetNet, such as frequent hand-overs between cells. It also included use of 256-QAM.
First technology demonstrations and field trials
This list covers technology demonstrations and field trials up to the year 2014, paving the way for a wider commercial deployment of the VoLTE technology worldwide. From 2014 onwards various further operators trialled and demonstrated the technology for future deployment on their respective networks. These are not covered here. Instead a coverage of commercial deployments can be found in the section below.
Deployment
The deployment of LTE-Advanced in progress in various
LTE networks.
In August 2019, the
Global mobile Suppliers Association
The Global mobile Suppliers Association (GSA) is a not-for-profit industry organisation representing companies in the mobile communication industry.
GSA actively promotes 3GPP technology such as 3G; 4G; 5G.
GSA is a market representation partn ...
(GSA) reported that there were 304 commercially launched LTE-Advanced networks in 134 countries. Overall, 335 operators are investing in LTE-Advanced (in the form of tests, trials, deployments or commercial service provision) in 141 countries.
LTE Advanced Pro
LTE Advanced Pro (LTE-A Pro, also known as 4.5G, 4.5G Pro, 4.9G, Pre-5G, 5G Project) is a name for
3GPP release 13 and 14. It is an evolution of LTE Advanced (LTE-A) cellular standard supporting data rates in excess of 3 Gbit/s using 32-
carrier aggregation
Carrier aggregation is a technique that is used in wireless communication to increase the data rate per user, whereby multiple frequency blocks (called ''component carriers'') are assigned to the same user. The maximum possible data rate per user i ...
. It also introduces the concept of
License Assisted Access LTE in unlicensed spectrum (LTE-Unlicensed, LTE-U) is an extension of the Long-Term Evolution (LTE) wireless standard that allows cellular network operators to offload some of their data traffic by accessing the unlicensed 5 GHz frequency band. LTE- ...
, which allows sharing of licensed and unlicensed spectrum.
Additionally, it incorporates several new technologies associated with
5G, such as 256-
QAM
Quadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. It conveys two analog message signa ...
, Massive
MIMO
In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of wi ...
,
LTE-Unlicensed and
LTE IoT
Narrowband Internet of things (NB-IoT) is a low-power wide-area network (LPWAN) radio technology standard developed by 3GPP for cellular devices and services. The specification was frozen in 3GPP Release 13 (LTE Advanced Pro), in June 2016. Oth ...
, that facilitated early migration of existing networks to enhancements promised with the full
5G standard.
See also
*
E-UTRA
E-UTRA is the air interface of 3rd Generation Partnership Project ( 3GPP) Long Term Evolution (LTE) upgrade path for mobile networks. It is an acronym for Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access, also r ...
*
LTE User Equipment Category
E-UTRA is the air interface of 3rd Generation Partnership Project ( 3GPP) Long Term Evolution (LTE) upgrade path for mobile networks. It is an acronym for Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access, also r ...
*
Simulation of LTE Networks
*
4G
*
5G
Bibliography
Qualcomm''LTE for UMTS - OFDMA and SC-FDMA Based Radio Access'',
Chapter 2.6: LTE Advanced for IMT-advanced pp. 19–21.
* e,:-(editor), ''LTE and the Evolution to 4G Wireless: Design and Measurement Challenges'', Agilent Technologies Publication 2009,
Chapter 8.7: Proving LTE Advanced p. 425.
*, et al.; Nokia Siemens Networks;
tp://lenst.det.unifi.it/pub/LenLar/proceedings/2009/wv09/WVITAE09/PDF/AUTHOR/WV091418.PDF LTE Advanced: The Path towards Gigabit/s in Wireless Mobile Communications Wireless VITAE'09.
*
Mobile Terminal Receiver Design: LTE and LTE-Advanced ', .
References
External links
page on
Qualcomm site
3GPP Official 3GPP Standardisation Page on LTE AdvancedFuture use of LTE A femtocells
LTE-3GPP online decoders3GPP LTE / LTE Advanced online L3 messages decoders (24.008, 44.018, 44.060, etc.) supporting Release 14
Resources (white papers, technical papers, application notes)
LTE-Advanced Technology Introductionwhite paper summarizing improvements on LTE known as LTE-Advanced Release 10
Introducing LTE-AdvancedApplication Note
Introduction to LTE-Advanced Rel.11summarization of improvements specified in LTE-Advanced Release 11
{{Telecommunications
Japanese inventions
LTE (telecommunication)
Mobile technology
Telecommunications