4G

4G refers to the fourth generation of cellular network technology. It was introduced in the late 2000s and early 2010s. This new technology was designed to support all kinds of data and internet services better than its predecessor, 3G. With 4G, people could enjoy faster internet speeds and more reliable connections.

Compared to 3G, 4G offered much higher data bandwidth. This made it possible to stream high-definition videos smoothly and support many internet-connected devices, which helped grow the Internet of Things. Two main technologies were marketed as 4G: Long-Term Evolution (LTE) and Mobile Worldwide Interoperability for Microwave Access (Mobile WiMAX). Both of these technologies provided big improvements over the older 3G and 2G networks.

Technical overview

In November 2008, a group called the International Telecommunication Union-Radio communications sector specified rules for 4G networks. They wanted these networks to be very fast — up to 100 megabits per second for people moving around, like in cars, and up to 1 gigabit per second for people standing still or walking.

Some early versions of technologies like Mobile WiMAX and LTE weren’t quite fast enough to meet these rules, but companies still called them 4G. In 2010, the group said that even if a technology wasn’t perfectly fast, it could still be called 4G if it was much better than older systems and would get even better in the future. Later, in 2012, they said that newer versions like Mobile WiMAX Release 2 and LTE Advanced were the real 4G.

Unlike older networks, 4G doesn’t use the old way of making phone calls. Instead, it uses a system based on the Internet Protocol, which helps it send lots of data very quickly, even when there are many signals bouncing around. This makes 4G much faster and better for things like watching videos or using apps that need the internet.

Background

In mobile communications, each "generation" brings big changes. These changes include new ways to send information, faster speeds, and better ability to handle many users at once.

New generations of mobile tech have come about every ten years. Starting from analog (1G) in 1981 to digital (2G) in 1992, then 3G in 2001, and finally 4G in 2011/2012. 4G brought ultra-fast speeds and all-digital networks for better mobile internet. The group that sets rules for global communications, ITU-R, gave guidelines for what counts as 3G and later 4G, but other groups like IEEE and 3GPP did the actual work.

Frequencies for 4G+ LTE networks

Main article: LTE frequency bands

This section lists the different frequencies used by 4G+ LTE networks. These frequencies help mobile devices connect to the internet and communicate with each other. The specific frequencies can vary depending on the country and network provider.

IMT-Advanced requirements

This article talks about 4G using a special name called IMT-Advanced, which was set by ITU-R. For a system to be called IMT-Advanced, it needs to meet some important rules.

These rules include having a network that only sends data in packets, supporting very fast speeds (up to about 100 Mbit/s when moving and up to 1 Gbit/s when staying in one place), sharing network space for many users at once, using different sizes of signal bands, and smoothly switching between different networks.

In 2009, different technologies were suggested for 4G. The main ones were LTE Advanced and 802.16m. Some early versions of these technologies were seen as steps toward full 4G but did not completely meet all the rules.

System standards

IMT-2000 compliant 4G standards

As of October 2010, two technologies (LTE Advanced and WirelessMAN-Advanced) were approved for the ITU's International Mobile Telecommunications Advanced program. This program focuses on future global communication systems.

LTE Advanced

Main article: LTE Advanced

LTE Advanced is a improvement to the existing LTE network. It uses extra spectrums and methods to reach higher data speeds. LTE Advanced helps handle more data.

IEEE 802.16m or WirelessMAN-Advanced

The IEEE 802.16m or WirelessMAN-Advanced is being developed to reach very high speeds for both stationary and mobile use.

Forerunner versions

Long-Term Evolution (LTE)

Main article: LTE (telecommunication)

The pre-4G 3GPP Long-Term Evolution (LTE) is often called "4G – LTE". LTE can reach speeds up to 100 Mbit/s downlink and 50 Mbit/s uplink.

The world's first LTE service opened in Stockholm and Oslo on December 14, 2009.

Mobile WiMAX (IEEE 802.16e)

The Mobile WiMAX standard is sometimes called 4G, with speeds up to 128 Mbit/s downlink and 56 Mbit/s uplink.

In June 2006, the world's first Mobile WiMAX service opened in Seoul, South Korea.

In the latest version, WiMax 2.1, the standard is now interchangeable with LTE-TDD system.

TD-LTE for China market

As LTE grew, it became a main 4G standard in China. TD-LTE became China’s 4G standard, amended and published by China Mobile.

Discontinued candidate systems

UMB (formerly EV-DO Rev. C)

Main article: Ultra Mobile Broadband

UMB was a discontinued 4G project to improve the CDMA2000 standard. In November 2008, Qualcomm ended development, favoring LTE instead.

Flash-OFDM

At an early stage the Flash-OFDM system was expected to become a 4G standard.

iBurst and MBWA (IEEE 802.20) systems

The iBurst system was later developed into the Mobile Broadband Wireless Access (MBWA) system, also known as IEEE 802.20.

Principal technologies in all candidate systems

4G networks have special features that make them work better than older ones. These include smart ways to send information using many antennas, which helps send more data faster. They also use methods to organize data so it can move quickly and efficiently.

New ways to share data, like OFDMA and SC-FDMA, help control how much data can be sent and keep things running smoothly. These methods also make it easier to send data without needing too much power.

Unlike older networks, 4G uses only one type of connection for all data, which makes things faster. It also needs IPv6 to handle many devices connecting at once. This helps avoid problems when many devices try to talk to each other at the same time.

4G also uses advanced antenna systems, like MIMO, to improve how well it sends and receives data over long distances. These systems help make sure data arrives clearly even when conditions are tricky.

Another important part of 4G is open wireless architecture, which lets devices use many different ways to connect. This makes 4G flexible and able to work with many standards.

History of 4G and pre-4G technologies

In 1991, WiLAN founders Hatim Zaghloul and Michel Fattouche invented wideband orthogonal frequency-division multiplexing (WOFDM), the basis for wideband wireless communication applications, including 4G mobile communications.

The 4G system was originally envisioned by the DARPA, the US Defense Advanced Research Projects Agency. DARPA chose a distributed architecture and end-to-end Internet protocol (IP), believing early on in peer-to-peer networking where every mobile device would act as both a receiver and sender for other devices, improving on older systems.

Since the 2.5G GPRS system, cellular systems have used two types of connections: one for data and one for voice calls. In 4G systems, the old voice call system was replaced with IP telephony, using only one type of connection for all communications.

• In 2002, the strategic vision for 4G was introduced.
• In 2004, LTE was first suggested by NTT DoCoMo of Japan.
• In 2005, OFDMA transmission technology was chosen for HSOPA downlink, later named 3GPP Long-Term Evolution (LTE) air interface E-UTRA.
• In November 2005, KT Corporation showed mobile WiMAX service in Busan, South Korea.
• In April 2006, KT Corporation began the world's first commercial mobile WiMAX service in Seoul, South Korea.
• In mid-2006, Sprint planned to invest in WiMAX technology.
• In February 2007, NTT DoCoMo tested a 4G system prototype in Japan.
• In September 2007, NTT Docomo showed high-speed data rates with low power use.
• In January 2008, a U.S. Federal Communications Commission auction for 700 MHz frequencies began.
• In January 2008, a European official suggested setting aside spectrum for wireless communication.
• On 15 February 2008, Skyworks Solutions introduced a module for e-UTRAN.
• In November 2008, ITU-R set performance requirements for IMT-Advanced.
• In April 2008, 3GPP decided that LTE Advanced would meet IMT-Advanced requirements.
• In April 2008, LG and Nortel showed high-speed data rates while moving.
• On 12 November 2008, HTC announced the first WiMAX-enabled mobile phone, the Max 4G
• On 15 December 2008, San Miguel Corporation partnered to build wireless projects in the Philippines.
• On 3 March 2009, Lithuania announced the first "4G" mobile WiMAX network in the Baltic states.
• In December 2009, Sprint advertised "4G" service in some U.S. cities.
• On 14 December 2009, the first commercial LTE service began in Stockholm and Oslo.
• On 4 June 2010, Sprint released the first WiMAX smartphone in the US, the HTC Evo 4G.
• On November 4, 2010, the Samsung Craft became the first commercial LTE smartphone.
• On 6 December 2010, the ITU stated that LTE and WiMAX could be considered "4G".
• In 2011, Argentina's Claro began a pre-4G network.
• In 2011, Thailand's Truemove-H began a pre-4G network.
• On March 17, 2011, the HTC Thunderbolt became the second LTE smartphone in the U.S.
• In February 2012, Ericsson showed mobile-TV over LTE.

Since 2009, the LTE standard has grown, with many operators around the world using it.

Disadvantages

4G can be tricky if you travel to different countries or want to switch phone carriers. To use 4G voice calls (VoLTE), your phone needs the right frequency band and sometimes needs to be unlocked. Even if your phone works with one carrier, it might not work with another, especially when traveling internationally, unless you get a special software update. However, you can still make regular voice calls using older 2G or 3G networks if they are available.

Beyond 4G research

Main article: 5G

Researchers are working on ways to improve 4G technology so that more users can get fast speeds, even those far from a single tower. They use special methods like macro-diversity and Beam-Division Multiple Access to help with this.

Another idea being studied is called pervasive networks. In these networks, a device could connect to many different types of wireless networks at once, like Wi-Fi or UMTS, and switch between them easily. This would need smart technology to manage how radio waves are used and to create a network that can work together.

The future of 4G

Since 2023, many places have begun changing from 4G to 5G, which is the new kind of mobile internet. 5G will be quicker, respond faster, and let many devices connect at once.

For some time, 4G and 5G will both be used together. 4G will still help places that do not yet have 5G.

Past 4G networks

This section talks about when some older types of fast internet connections for phones, like WiMAX and LTE, stopped being used. For information about when other fast internet connections, such as HSPA+ (which is part of UMTS but sometimes called 4G), stopped being used, see 3G § Phase-out.