# 4G
**4G** (fourth generation) is the marketing and industry label for the fourth generation of cellular mobile networks, associated with the [International Telecommunication Union](https://www.edgepedia.org/international-telecommunication-union)'s IMT-Advanced framework of broadband mobile standards. The ITU itself does not define the term "4G"; the technologies it designated IMT-Advanced, principally LTE-Advanced and WirelessMAN-Advanced, are the standards most closely identified with the generation, while operators also apply the label to earlier forerunners such as LTE, HSPA+, and WiMAX.[1](https://www.itu.int/hub/2022/02/mobile-broadband-standards-imt-5g/) • [2](https://www.itu.int/ITU-D/tech/MobileCommunications/IMT_INTRODUCING/IMT_2G3G4G.html) In practice, 4G rests on [Long Term Evolution](https://www.edgepedia.org/lte-telecommunication) (LTE) and its enhanced variant LTE-Advanced, developed by the 3rd Generation Partnership Project (3GPP).[3](https://technav.ieee.org/topic/4g-mobile-communication/)
| Key fact | Detail |
|---|---|
| Official framework | IMT-Advanced, specified by ITU-R; LTE-Advanced and WirelessMAN-Advanced received the official IMT-Advanced designation, with specifications agreed by the ITU Radiocommunication Assembly in January 2012[2](https://www.itu.int/ITU-D/tech/MobileCommunications/IMT_INTRODUCING/IMT_2G3G4G.html) |
| Performance targets | 100 Mbit/s for high mobility and 1 Gbit/s for low mobility, established as research targets for IMT-Advanced[4](https://www.itu.int/epublications/en/publication/recommendation-itu-r-m-2012-7-02-2026-detailed-specifications-of-the-terrestrial-radio-interfaces-of-international-mobile-telecommunications-advanced-imt-advanced/en) |
| Core technologies | LTE (3GPP Release 8) and LTE-Advanced (Release 10); WirelessMAN-Advanced (IEEE 802.16m) was the competing IMT-Advanced candidate[3](https://technav.ieee.org/topic/4g-mobile-communication/) • [5](https://catalogimages.wiley.com/images/db/pdf/9781119847472.excerpt.pdf) |
| Architecture | All-IP packet-switched design replacing the 3G circuit-switched domain; flat radio network (E-UTRAN) with the Evolved Packet Core (EPC)[3](https://technav.ieee.org/topic/4g-mobile-communication/) |
| Air interface | OFDMA in the downlink, SC-FDMA in the uplink[3](https://technav.ieee.org/topic/4g-mobile-communication/) |
| First commercial launch | December 2009, TeliaSonera with Ericsson in Stockholm, the world's first commercial 4G/LTE network[6](https://www.ericsson.com/en/about-us/history/company/timeline-placeholder/timeline-2010-4g-arrives) |
| Current role | In the UK in 2025, 4G still carried approximately 72% of total monthly mobile data traffic, down 6 percentage points year on year[7](https://www.ofcom.org.uk/siteassets/resources/documents/research-and-data/multi-sector/infrastructure-research/connected-nations-2025/connected-nations-uk-report-2025.pdf) |
## Naming and the IMT-Advanced framework
The ITU's International Mobile Telecommunications (IMT) family assigns technical specifications, not marketing labels: IMT-2000 covers 3G, IMT-Advanced covers the all-IP mobile broadband protocols commonly called 4G, and IMT-2020 covers 5G.[1](https://www.itu.int/hub/2022/02/mobile-broadband-standards-imt-5g/) The ITU states that it has no definition for 3G, 4G, or 5G and takes no position on how a technology is labeled for marketing purposes; the term "4G" remains undefined but is applied by some operators to forerunners of IMT-Advanced technologies, including LTE, HSPA+ (Evolved High-Speed Packet Access), and WiMAX, which improved substantially on initial 3G systems.[1](https://www.itu.int/hub/2022/02/mobile-broadband-standards-imt-5g/)
The performance targets came from ITU-R work on systems beyond IMT-2000: 100 Mbit/s for high mobility and 1 Gbit/s for low mobility were established as research targets, sourced from Recommendation ITU-R M.1645.[4](https://www.itu.int/epublications/en/publication/recommendation-itu-r-m-2012-7-02-2026-detailed-specifications-of-the-terrestrial-radio-interfaces-of-international-mobile-telecommunications-advanced-imt-advanced/en) Ericsson's history records that in March 2008 the ITU-R defined the standard for 4G with these goals, and that the initial networks launched as 4G did not reach these speeds but are retrospectively referred to as 4G.[6](https://www.ericsson.com/en/about-us/history/company/timeline-placeholder/timeline-2010-4g-arrives) Because LTE alone could not fully comply with the IMT-Advanced requirements, such as the 1 Gbps peak rate for low mobility and 100 Mbps for high mobility, 3GPP continued work from 2009 on an enhanced version, LTE-Advanced.[5](https://catalogimages.wiley.com/images/db/pdf/9781119847472.excerpt.pdf)
On 20 October 2010, at the [Chongqing](https://www.edgepedia.org/chongqing) meeting of ITU-R Working Party 5D, the 3GPP candidate developed as LTE Release 10 and Beyond (LTE-Advanced) was accepted as a 4G technology, having completed steps 4 through 7 of the IMT-Advanced process and complied with or exceeded the ITU criteria in all aspects; final ratification of the full IMT-Advanced technology family followed at the ITU-R Study Group 5 meeting in November 2010.[8](https://www.3gpp.org/news-events/3gpp-news/itu-r-confers-imt-advanced-4g-status-to-3gpp-lte) The competing candidate, IEEE 802.16m-2011 (WirelessMAN-Advanced), was submitted to the ITU by the IEEE and WiMAX Forum, and ITU ultimately accorded both LTE-Advanced and WirelessMAN-Advanced the official IMT-Advanced designation.[5](https://catalogimages.wiley.com/images/db/pdf/9781119847472.excerpt.pdf) • [2](https://www.itu.int/ITU-D/tech/MobileCommunications/IMT_INTRODUCING/IMT_2G3G4G.html)
## LTE technology and architecture
4G represents a break from the 3G architecture in its use of an all-IP network design: where 3G blended circuit-switched voice with packet data, 4G treats voice and data as services over a unified IP core, eliminating the legacy circuit domain.[9](https://technav.ieee.org/topic/4-g-wireless/) • [3](https://technav.ieee.org/topic/4g-mobile-communication/) 3GPP began two parallel projects, Long Term Evolution (LTE) for the radio access network and System Architecture Evolution (SAE) for the core, both included in Release 8.[10](https://people.eecs.berkeley.edu/~randy/Courses/CS294.S13/13.1.pdf)
The LTE specification adopted a flattened network design built around two principal elements: the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), handling the radio portion, and the [Evolved Packet Core](https://www.edgepedia.org/evolved-packet-core) (EPC), handling the backhaul portion. Base stations called eNodeBs communicate directly with one another over the [X2 interface](https://www.edgepedia.org/x2-interface) and connect to the EPC over the S1 interface, removing the centralized controller hop of 3G and simplifying handover.[3](https://technav.ieee.org/topic/4g-mobile-communication/) • [11](https://technav.ieee.org/topic/long-term-evolution/) The downlink uses Orthogonal Frequency-Division Multiple Access (OFDMA) and the uplink Single-Carrier FDMA (SC-FDMA), chosen for spectral efficiency and resistance to multipath fading; MIMO antenna techniques are integral to the physical layer.[3](https://technav.ieee.org/topic/4g-mobile-communication/) • [11](https://technav.ieee.org/topic/long-term-evolution/)
**LTE-Advanced.** Standardized in Release 10, LTE-Advanced added carrier aggregation, allowing devices to combine up to five component carriers for peak downlink rates above 1 Gbit/s, along with enhanced MIMO configurations, heterogeneous network support using small cells alongside macro base stations, and coordinated multipoint transmission.[11](https://technav.ieee.org/topic/long-term-evolution/) The LTE-Advanced radio-access network uses a flat architecture with a single node type, the eNodeB, responsible for all radio-related functions in one or several cells.[4](https://www.itu.int/epublications/en/publication/recommendation-itu-r-m-2012-7-02-2026-detailed-specifications-of-the-terrestrial-radio-interfaces-of-international-mobile-telecommunications-advanced-imt-advanced/en)
## Deployment history
The first commercial LTE 4G service launched in December 2009, when TeliaSonera and [Ericsson](https://www.edgepedia.org/ericsson) turned on the world's first and largest commercial LTE network in Stockholm, ahead of the original plan; customers accessed it through Samsung LTE dongles.[12](https://news.cision.com/ericsson/r/world-s-first-4g-lte-network-goes-live-today-in-stockholm%2Cc2246275) • [6](https://www.ericsson.com/en/about-us/history/company/timeline-placeholder/timeline-2010-4g-arrives) • [15](https://www.oecd.org/content/dam/oecd/en/publications/reports/2007/03/fixed-mobile-convergence_g17a1c05/231037284472.pdf) Within a decade LTE became the dominant cellular technology globally, carrying the majority of mobile data traffic in virtually every major market.[11](https://technav.ieee.org/topic/long-term-evolution/)
4G built directly on operators' 3G infrastructure investments while replacing the 3G air interface with the LTE physical layer; the transition required upgrades to base stations and core nodes but allowed reuse of licensed spectrum holdings.[3](https://technav.ieee.org/topic/4g-mobile-communication/) As 4G and 5G services spread, operators began retiring older generations: in the United Kingdom, all four mobile network operators have completed their 3G switch-offs to support 4G and 5G roll-out, with 2G retirement committed by 2033 at the latest.[7](https://www.ofcom.org.uk/siteassets/resources/documents/research-and-data/multi-sector/infrastructure-research/connected-nations-2025/connected-nations-uk-report-2025.pdf)
## Services and real-world performance
4G was principally designed for enhanced mobile broadband: high-throughput, continuous connectivity for smartphones, tablets, and portable devices. In deployed LTE-Advanced networks, real-world downlink speeds in favorable conditions reached several hundred Mbit/s, a step change from typical 3G speeds of a few Mbit/s, supported by channel bandwidths up to 100 MHz through carrier aggregation, higher-order modulation (64-QAM in Release 8, extended to 256-QAM later), and advanced MIMO.[3](https://technav.ieee.org/topic/4g-mobile-communication/) The radio access network aimed for latencies near 10 ms, enabling real-time services such as VoLTE and interactive video to work while users were moving.[3](https://technav.ieee.org/topic/4g-mobile-communication/) • [16](https://www.3gpp.org/ftp/tsg_sa/wg1_serv/TSGS1_03-HCourt/Docs/Docs/S1-99331/22101-350.pdf) VoLTE delivers voice as a digital packet service over IP via the LTE access network using IMS technology, and is recognized as the industry-agreed progression of voice services on LTE radio access.[13](https://www.gsma.com/solutions-and-impact/technologies/networks/ip_services/volte/)
Measured performance varies widely with location and load. A 2021 measurement campaign across tribal, rural, congested urban, and uncongested urban LTE networks found that under-provisioned tribal and rural areas had 9 times poorer video streaming quality, 10 times higher video start-up delay, and 11 times worse throughput and 3 times worse latency than urban deployments, despite identical carrier subscription plans.[14](https://experts.azregents.edu/en/publications/coverage-is-not-binary-quantifying-mobile-broadband-quality-in-ur/)
## 4G alongside 5G
The IMT-Advanced framework that defined 4G was followed by ITU-R's IMT-2020 vision, which set the requirements for 5G, extending the enhanced mobile broadband use case while adding massive machine-type and ultra-reliable low-latency service categories not addressed by 4G.[3](https://technav.ieee.org/topic/4g-mobile-communication/) [Non-standalone 5G](https://www.edgepedia.org/non-standalone-5g), the first deployment model, relies on an underlying 4G network, using a 5G radio access network with a 4G LTE core; only 5G standalone removes the dependency on 4G entirely.[1](https://www.itu.int/hub/2022/02/mobile-broadband-standards-imt-5g/) • [7](https://www.ofcom.org.uk/siteassets/resources/documents/research-and-data/multi-sector/infrastructure-research/connected-nations-2025/connected-nations-uk-report-2025.pdf) 4G remains central in practice: in the UK in 2025 it carried about 72% of monthly mobile data traffic, and LTE development continued through Release 15 before focus shifted to 5G New Radio.[7](https://www.ofcom.org.uk/siteassets/resources/documents/research-and-data/multi-sector/infrastructure-research/connected-nations-2025/connected-nations-uk-report-2025.pdf) • [11](https://technav.ieee.org/topic/long-term-evolution/)
## References
1. [An inside look at mobile broadband standards development, ITU News (25 February 2022)](https://www.itu.int/hub/2022/02/mobile-broadband-standards-imt-5g/)
2. [ITU-D Technologies, Infrastructures and Applications: Mobile Communications, 2G/3G/4G](https://www.itu.int/ITU-D/tech/MobileCommunications/IMT_INTRODUCING/IMT_2G3G4G.html)
3. [4G mobile communication, IEEE Technology Navigator](https://technav.ieee.org/topic/4g-mobile-communication/)
4. [Recommendation ITU-R M.2012-7 (02/2026), Detailed specifications of the terrestrial radio interfaces of IMT-Advanced](https://www.itu.int/epublications/en/publication/recommendation-itu-r-m-2012-7-02-2026-detailed-specifications-of-the-terrestrial-radio-interfaces-of-international-mobile-telecommunications-advanced-imt-advanced/en)
5. [Standards History of Cellular Systems Toward 6G, Wiley book excerpt](https://catalogimages.wiley.com/images/db/pdf/9781119847472.excerpt.pdf)
6. [2010: 4G arrives, Ericsson history timeline](https://www.ericsson.com/en/about-us/history/company/timeline-placeholder/timeline-2010-4g-arrives)
7. [Connected Nations UK Report 2025, Ofcom](https://www.ofcom.org.uk/siteassets/resources/documents/research-and-data/multi-sector/infrastructure-research/connected-nations-2025/connected-nations-uk-report-2025.pdf)
8. [ITU-R Confers IMT-Advanced (4G) Status to 3GPP LTE, 3GPP (20 October 2010)](https://www.3gpp.org/news-events/3gpp-news/itu-r-confers-imt-advanced-4g-status-to-3gpp-lte)
9. [4G, IEEE Technology Navigator](https://technav.ieee.org/topic/4-g-wireless/)
10. [The evolution to 4G cellular systems: LTE-Advanced, UC Berkeley course notes](https://people.eecs.berkeley.edu/~randy/Courses/CS294.S13/13.1.pdf)
11. [Long Term Evolution, IEEE Technology Navigator](https://technav.ieee.org/topic/long-term-evolution/)
12. [World's first 4G/LTE network goes live today in Stockholm, Ericsson press release (14 December 2009)](https://news.cision.com/ericsson/r/world-s-first-4g-lte-network-goes-live-today-in-stockholm%2Cc2246275)
13. [VoLTE (Voice over LTE), GSMA](https://www.gsma.com/solutions-and-impact/technologies/networks/ip_services/volte/)
14. [Coverage is Not Binary: Quantifying Mobile Broadband Quality in Urban, Rural, and Tribal Contexts, ICCCN 2021](https://experts.azregents.edu/en/publications/coverage-is-not-binary-quantifying-mobile-broadband-quality-in-ur/)
15. [oecd.org](https://www.oecd.org/content/dam/oecd/en/publications/reports/2007/03/fixed-mobile-convergence_g17a1c05/231037284472.pdf)
16. [3gpp.org](https://www.3gpp.org/ftp/tsg_sa/wg1_serv/TSGS1_03-HCourt/Docs/Docs/S1-99331/22101-350.pdf)
---
*Topic: Encyclopedia › Technology and the built world › Communications and everyday technology › Telephony systems and services › Cellular network generations (3G, 4G, 5G)*
*Initially written Sep 17, 2026 · Reviewed: Sep 17, 2026; Sep 30, 2026; Oct 15, 2026 · Edited: Sep 30, 2026; Oct 15, 2026 · Last review: Oct 15, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license