IMT Advanced


International Mobile Telecommunications-Advanced are the requirements issued by the ITU Radiocommunication Sector of the International Telecommunication Union in 2008 for what is marketed as 4G mobile phone and Internet access service.

Description

An IMT-Advanced system is expected to provide a comprehensive and secure all-internet protocol based mobile broadband solution to laptop computer wireless modems, smartphones, and other mobile devices. Facilities such as ultra-broadband Internet access, voice over IP, gaming services, and streamed multimedia may be provided to users.
IMT-Advanced is intended to accommodate the quality of service and rate requirements set by further development of existing applications like mobile broadband access, Multimedia Messaging Service, video chat, mobile TV, but also new services like high-definition television. 4G may allow roaming with wireless local area networks, and may interact with digital video broadcasting systems. It was meant to go beyond the International Mobile Telecommunications-2000 requirements, which specify mobile phones systems marketed as 3G.

Requirements

Specific requirements of the IMT-Advanced report included:
The first set of 3GPP requirements on LTE Advanced was approved in June 2008.
A summary of the technologies that have been studied as the basis for LTE Advanced is included in a technical report.
While the ITU adopts requirements and recommendations for technologies that would be used for future communications, they do not actually perform the development work themselves, and countries do not consider them binding standards. Other trade groups and standards bodies such as the Institute of Electrical and Electronics Engineers, the WiMAX Forum, and 3GPP also have a role.

Principal technologies

Physical layer transmission techniques expected to be used include:

Long Term Evolution

has a theoretical net bitrate maximum capacity of 100 Mbit/s in the downlink and 50 Mbit/s in the uplink if a 20 MHz channel is used. The capacity is more if a MIMO antenna array is used. The physical radio interface was at an early stage named "High Speed Orthogonal Packet Access" and is now named E-UTRA.
The CDMA's spread spectrum radio technology that was used in 3G systems and cdmaOne has been abandoned. It was replaced by orthogonal frequency-division multiple access and other frequency-division multiple access schemes. This is combined with MIMO antenna arrays, dynamic channel allocation, and channel-dependent scheduling.
The first publicly available LTE services were branded "4G" and opened in Sweden's capital city Stockholm and Norway's capital city Oslo on 14 December 2009. The user terminals were manufactured by Samsung. All four major U.S. wireless carriers offer LTE services.
In South Korea, SK Telecom and LG U+ have enabled access to LTE service since July 2011 for data devices, slated to go nationwide by 2012.

Mobile WiMAX (IEEE 802.16e)

The Mobile WiMAX mobile wireless broadband access standard is sometimes branded 4G, and offers peak data rates of 128 Mbit/s downlink and 56 Mbit/s uplink over 20 MHz wide channels.
The first commercial mobile WiMAX service was opened by KT in Seoul, South Korea in June 2006.
In September 2008, Sprint Nextel marketed Mobile WiMAX as a "4G" network even though it did not fulfil the IMT Advanced requirements.
In Russia, Belarus, and Nicaragua, WiMax broadband internet access is offered by the Russian company Scartel and is also branded 4G, Yota.
WiMAX
Peak download128 Mbit/s
Peak upload56 Mbit/s

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. The objective was to achieve data speeds over 275 Mbit/s downstream and over 75 Mbit/s upstream.

Flash-OFDM

At an early stage the Flash-OFDM system was expected to be further developed into a 4G standard.

iBurst and MBWA

The iBurst technology, using High Capacity Spatial Division Multiple Access, was at an early stage considered as a 4G predecessor. It was incorporated by the Mobile Broadband Wireless Access working group into the IEEE 802.20 standard in 2008.

Candidate systems

In October 2010, ITU-R Working Party 5D approved two industry-developed technologies.
On December 6, 2010, ITU noted that while current versions of LTE, WiMax and other evolved 3G technologies do not fulfill IMT-Advanced requirements for 4G, some may use the term "4G" in an "undefined" fashion to represent forerunners to IMT-Advanced that show "a substantial level of improvement in performance and capabilities with respect to the initial third generation systems now deployed."

LTE Advanced

was formally submitted by the 3GPP organization to ITU-T in the fall 2009, and was released in 2011. The target of 3GPP LTE Advanced was to reach and surpass the ITU requirements. LTE Advanced is an improvement on the existing LTE network.
Release 10 of LTE is expected to achieve the LTE Advanced speeds. Release 8 in 2009 supported up to 300 Mbit/s download speeds which was still short of the IMT-Advanced standards.

WiMAX Release 2 (IEEE 802.16m)

The WirelessMAN-Advanced evolution of IEEE 802.16e was published in May 2011 as standard IEEE 802.16m-2011. The relevant industry promoting the technology gave it the marketing name of WiMAX Release 2. It had an objective to fulfill the IMT-Advanced criteria. The IMT-Advanced group formally approved this technology as meeting its criteria in October 2010. In the second half of 2012, the 802.16m-2011 standard was rolled up into the 802.16-2012 standard, excluding the WirelessMAN-Advanced radio interface part of the 802.16m-2011 standard, which got moved to IEEE Std 802.16.1-2012.

Comparison

The following table shows a comparison of IMT-Advanced candidate systems as well as other competing technologies.