4G

4G refers to the fourth generation of cellular network technology. It started in the late 2000s and early 2010s. This technology was made to work better with all kinds of data and internet services than the older 3G.

With 4G, people got faster internet speeds and more reliable connections.

Compared to 3G, 4G could handle much more data. This let people stream high-definition videos easily and connect many devices to the internet. This helped grow the Internet of Things. Two main technologies were called 4G: Long-Term Evolution (LTE) and Mobile Worldwide Interoperability for Microwave Access (Mobile WiMAX). Both of these technologies worked much better than the older 3G and 2G networks.

Technical overview

In November 2008, a group called the International Telecommunication Union-Radio communications sector made 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, 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 talk to each other. The exact frequencies can change depending on the country and the 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 sends data in small pieces, supporting very fast speeds (up to about 100 Mbit/s when moving and up to 1 Gbit/s when staying in one place), sharing space for many users at once, using different sizes of signal bands, and switching smoothly 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 looks at future global communication systems.

LTE Advanced

Main article: LTE Advanced

LTE Advanced improves 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. They use smart ways to send information with 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 using 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). This became the basis for wideband wireless communication applications, including 4G mobile communications.

The 4G system was first thought up by the DARPA, the US Defense Advanced Research Projects Agency. DARPA chose a distributed design and an Internet protocol (IP). They believed that every mobile device could send and receive information for other devices, which was an improvement over older systems.

Since the 2.5G GPRS system, mobile networks 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. Now, only one type of connection is used for all communications.

• In 2002, the idea 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. But 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 trying to make 4G technology better. They want more people to get fast speeds, even if they are far from a tower. They use special methods like macro-diversity 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. It could switch between them easily. This would need smart technology to manage radio waves and create a network that works together.

The future of 4G

Since 2023, many places have started using 5G instead of 4G. 5G is a new kind of mobile internet that will be faster and better. It will also let many devices connect at the same time.

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

Past 4G networks

This section talks about when some older fast internet connections for phones stopped being used, like WiMAX and [LTE](/wiki/LTE_(telecommunication). For more 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.