4G facts for kids

This page is about the mobile internet access standard. For other uses, see 4G (disambiguation).

4G is the fourth generation of cellular network technology. It came after 3G and before 5G. Think of it as a big upgrade for your mobile internet!

4G lets you do many cool things. You can browse the mobile web super fast. You can make calls over the internet, play online games, watch HD videos on your phone, and even have video calls.

At first, the ITU (International Telecommunication Union) had strict rules for what could be called 4G. But in 2010, they made the rules wider. This meant technologies like Long Term Evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX) could also be called 4G.

The first WiMAX networks started in South Korea in 2006. LTE networks first launched in Oslo, Norway, and Stockholm, Sweden, in 2009. These technologies quickly spread around the world.

Each new generation of mobile networks brings more speed. 4G can reach speeds of up to 150 Mbit/s for downloading and 50 Mbit/s for uploading. This is much faster than 3G, which had peak speeds of 7.2 Mbit/s download and 2 Mbit/s upload.

As of 2022^[update] 4G technology was used for 60% of all mobile connections worldwide.

What Makes 4G Special?

4G networks brought many improvements to how we use our phones and devices.

Speed: 4G networks are much faster for downloading and uploading data than 3G. In theory, 4G can reach speeds of 100 megabits per second (Mbit/s) if you are moving fast, like in a car. It can even reach 1 gigabit per second (Gbit/s) if you are standing still.
Less Delay: There is less "lag" or delay (called latency) with 4G. This makes apps and games feel more responsive.
More Capacity: 4G networks can handle more people using the internet at the same time. This means fewer slowdowns when many people are online.
Better Antennas: 4G uses smart antenna technologies like MIMO. These help signals travel better and use the network more efficiently.

How 4G Works (A Quick Look)

In 2008, the ITU-R set out rules for 4G standards. These rules, called IMT-Advanced, said 4G should be super fast. It needed to be 100 Mbit/s for people moving (like in a car) and 1 Gbit/s for people standing still.

Some early versions of Mobile WiMAX and LTE were not quite that fast. But phone companies still called them "4G" because they were a huge step up from 3G. The ITU-R later agreed that these improved 3G technologies could be called 4G. This was because they offered much better performance.

Unlike older networks, 4G systems do not use traditional phone lines for calls. Instead, everything, including calls, uses Internet Protocol (IP). This means calls are made over the internet, like VoIP. 4G also uses advanced radio technologies to send data very quickly, even with many signals bouncing around.

The History of Mobile Generations

A "generation" in mobile communication means a big change. It usually involves new technology, faster speeds, and more capacity.

New mobile generations have appeared about every ten years:

1G (around 1981): First analog phones.
2G (around 1992): Digital phones, allowing text messages.
3G (around 2001): Added multimedia support and faster internet.
4G (around 2011/2012): All-internet-based networks with super-fast mobile internet.

The ITU helps set the goals for these new technologies. But other groups like IEEE and 3GPP do the actual work of creating the standards.

The fastest 3G standard was HSPA+. It could reach 21 Mbit/s download speeds. Later versions could even go up to 42 Mbit/s.

What 4G Needs to Do (IMT-Advanced)

The official rules for 4G (called IMT-Advanced by the ITU-R) say a 4G system must:

Be based completely on an IP network. This means all data, including calls, travels over the internet.
Have peak speeds of about 100 Mbit/s for mobile users and up to 1 Gbit/s for users standing still.
Be able to share network resources smartly to support many users at once.
Use flexible channel widths, usually 5–20 MHz, sometimes up to 40 MHz.
Allow smooth switching between different networks.

Two main technologies were proposed to meet these rules:

LTE Advanced (from 3GPP)
802.16m (from IEEE, also known as WiMAX 2)

Early versions of Mobile WiMAX and LTE were seen as temporary solutions. They offered a big speed boost until the truly advanced versions (WiMAX 2 and LTE Advanced) were ready. These advanced versions were approved in 2011.

Some people called the first LTE and Mobile WiMAX versions "pre-4G" or "3.9G." This was because they didn't fully meet the super-fast speed goals. But today, the ITU-R says they can be called 4G.

Main 4G Systems

LTE Advanced

LTE Advanced is an improved version of LTE. It was designed to meet and even go beyond the ITU's 4G requirements. It is not a completely new technology but an upgrade to existing LTE networks. This makes it easier and cheaper for companies to offer faster speeds. LTE Advanced uses more radio frequencies and smart ways to send data faster.

Data speeds of LTE-Advanced
	LTE Advanced
Peak download	1000 Mbit/s
Peak upload	0500 Mbit/s

IEEE 802.16m or WirelessMAN-Advanced

This is also known as WiMAX 2. It is being developed to meet the IMT-Advanced goals of 1 Gbit/s for stationary users and 100 Mbit/s for mobile users.

Early 4G Versions

Long Term Evolution (LTE)

A Telia-branded Samsung LTE modem

A Huawei 4G+ Dual Band Modem

The first version of 3GPP Long Term Evolution (LTE) is often called "4G – LTE." It could reach theoretical speeds of up to 100 Mbit/s for downloading and 50 Mbit/s for uploading. Even faster speeds were possible with special antennas.

The world's first public LTE service started in Stockholm and Oslo on December 14, 2009. It was called "4G." Many countries quickly followed, including the United States, South Korea, Hungary, and the United Kingdom.

Data speeds of LTE
	LTE
Peak download	0150 Mbit/s
Peak upload	0050 Mbit/s

Mobile WiMAX (IEEE 802.16e)

The Mobile WiMAX standard is also sometimes called 4G. It offers peak speeds of 128 Mbit/s for downloading and 56 Mbit/s for uploading.

The first commercial mobile WiMAX service began in Seoul, South Korea, in June 2006. Companies like Sprint in the US and Yota in Russia also offered WiMAX, calling it "4G."

Data speeds of WiMAX
	WiMAX
Peak download	0128 Mbit/s
Peak upload	0056 Mbit/s

The newest version of WiMAX (WiMAX 2.1) is now designed to work with LTE-TDD systems. This means WiMAX and LTE are becoming more similar.

TD-LTE for China

TD-LTE is a version of LTE that is very important in China. It was developed by China Mobile, one of China's biggest phone companies. Many companies around the world are now looking at TD-LTE.

How 4G Technologies Work Together

All 4G technologies share some key features:

Smart Antennas (MIMO): These use multiple antennas to send and receive data. This helps achieve super-high speeds and makes the network more efficient.
Frequency Use: They use special ways to send data across different frequencies. This helps transfer data very quickly without complex systems.
Error Correction: They use advanced codes to fix errors in data transmission. This makes sure your data arrives correctly.
Smart Scheduling: Networks can adjust how they send data based on how good the signal is.
Adaptive Modulation: They change how data is sent to match the signal quality.
Mobile IP: This allows your device to stay connected to the internet even as you move between different network areas.
IP-based Femtocells: These are small home base stations that connect to your home internet.

Unlike older networks, 4G systems only use packet switching. This means all data is broken into small "packets" and sent over the internet.

Using Different Frequencies

New ways of using frequencies, like OFDMA and SC-FDMA, are very important for 4G. These methods help manage bandwidth flexibly and achieve higher data rates. They also make it easier for your phone to receive signals, especially with smart antenna systems.

IPv6 Support

4G networks use IPv6. This is the newest version of internet addresses. It provides a huge number of addresses, which is needed for all the devices that connect to the internet today. IPv6 helps avoid problems that come with sharing a limited number of older IPv4 addresses.

Advanced Antenna Systems

Multiple antenna technologies are key to 4G. They help achieve high speeds and reliable communication. MIMO allows devices to send and receive multiple streams of data at the same time. This multiplies the basic data rate. It also improves reliability when sending fast data.

Open Wireless and Software-Defined Radio

Open Wireless Architecture (OWA) means that 4G systems can support different wireless technologies on one platform.

SDR is a type of OWA. Since 4G includes many different standards, SDR technology helps devices work with all of them efficiently.

The Future of 4G

As of 2023, many countries are starting to switch from 4G to 5G. 5G is the next generation of mobile technology. It promises even faster speeds, even less delay, and the ability to connect a huge number of devices at once.

However, 4G networks will still be around for many years. They will provide coverage in places where 5G is not yet available.

Past 4G Networks

Some 4G networks have been shut down as technology advances. This table shows a few examples:

Country	Network	Shutdown date	Standard
Canada	Xplore Mobile	2022-08-31	LTE
Jamaica	Digicel	2018-10-31	WiMAX
Malaysia	Yes 4G	2019-10-01	WiMAX
Nepal	Nepal Telecom	2021-12-??	WiMAX
Trinidad and Tobago	Blink bmobile (TSTT)	2015-03-03	WiMAX
United States	Sprint	2016-03-31	WiMAX
United States	T-Mobile (Sprint)	2022-06-30	LTE