5G
5G is the fifth generation of cellular network technology and the successor to 4G. First deployed in 2019, its technical standards are developed by the 3rd Generation Partnership Project in cooperation with the ITU’s IMT-2020 program. 5G networks divide coverage areas into smaller zones called cells, enabling devices to connect to local base stations via radio. Each station connects to the broader telephone network and the Internet through high-speed optical fiber or wireless backhaul.
Compared to 4G, 5G offers significantly faster data transfer speed—up to 10 Gbit/s in tests—and lower latency, with response times of just a few milliseconds. These advancements allow networks to support more users and applications such as extended reality, autonomous vehicles, remote surgery trials, and fixed wireless access for home Internet access. 5G also supports massive connectivity for sensors and machines, commonly referred to as the Internet of things, and leverages edge computing to improve data processing efficiency.
File:Verizon-n77-upgrade-after-before-v0-q1zq1mdxeadf1.png|thumb|alt=Close-up of antennas and radio units on a monopole tower.|A 5G cell site using Ericsson equipment in the United States
Building 5G networks requires new infrastructure and access to suitable radio spectrum. Network operators report high costs and continue to improve energy efficiency and security. Analysts expect 5G to support telehealth, smart transport, and digital media, while operating alongside 4G networks into the 2030s.
History
Early research (2008–2012)
In 2008, NASA and the Machine-to-Machine Intelligence Corporation conducted nanosatellite communication studies that influenced early next-generation network concepts.In 2012, New York University established NYU Wireless, a research center focused on millimeter-wave communication. The same year, the University of Surrey founded the 5G Innovation Centre, funded by £35 million from public and industry partners including Huawei and Samsung. Also in 2012, the European Union launched the Mobile and Wireless Communications Enablers for the Twenty-Twenty Information Society project to align emerging network research with international standardization.
Standardization and early trials (2013–2018)
In 2013, the ITU-R Working Party 5D began studies on IMT-2020, later formalized as the 5G standard.During the same period, major firms such as Samsung Electronics, NTT Docomo, and Huawei conducted early trials. Samsung tested a prototype achieving more than 1 Gbit/s across 2 km using 8 × 8 MIMO antennas. NTT Docomo received a government award at CEATEC for high-speed network development, while Huawei announced a US$600 million program to advance mobile network technology.
Commercial rollout (2019–2021)
On April 3, 2019, South Korea launched its national network, the first full commercial deployment. Hours later, Verizon began limited service in select U.S. cities. In June 2019, Globe Telecom introduced the Philippines’ first next-generation network, and in December 2019, AT&T launched a consumer service in the United States that expanded nationwide during 2020.Commercial 5G deployment expanded rapidly through 2020. Beyond public mobile networks, it was also adopted in private industrial and enterprise systems, including operation in unlicensed spectrum and licensed non-public networks. Private 5G networks became important for Industry 4.0 automation and smart manufacturing. Early rollouts used non-standalone mode—with 4G cores—before networks transitioned to standalone mode with dedicated 5G cores.
South Korea’s 2019 rollout used equipment from Samsung, Ericsson, and Nokia; LG U Plus also deployed Huawei hardware.
Samsung supplied most of the roughly 86,000 sites, while SK Telecom, KT Corporation, and LG U Plus concentrated coverage in major cities using the 3.5 GHz band under NSA operation. Reported download speeds averaged 200–400 Mbit/s, and subscriptions grew from about 260,000 to 4.7 million during 2019.
Following these early deployments, T-Mobile US launched the first nationwide standalone network in 2020. Ericsson projected that by the mid-2020s, 5G networks would reach about 65 percent of the global population.
Major suppliers of 5G radio and core systems included Altiostar, Cisco Systems, Datang Telecom/Fiberhome, Ericsson, Huawei, Nokia, Qualcomm, Samsung, and ZTE. Huawei was estimated to hold about 70 percent of global 5G base stations by 2023.
Recent developments (2022–present)
By 2022, network speeds in many regions had stabilized, and operators began testing 5.5G upgrades to improve capacity and latency. By the early 2020s, large-scale commercial 5G networks were active across most developed markets, and rollout in developing regions was still accelerating.Technologies
Small cells
Small cells are low-power radio nodes that extend network capacity in dense or indoor areas. They operate over short distances, typically a few dozen to a few hundred metres, and are used to maintain coverage for mmWave signals.| Cell type | Environment | Users | Power | Range |
| Femtocell | Homes, offices | 4–32 | 0.01–1 | up to 50 |
| Picocell | Public venues | 64–128 | 0.1–5 | up to 100 |
| Microcell | Urban areas | 128–256 | 5–10 | 200–500 |
| Macrocell | Wide-area coverage | over 250 | 10–20 | 300–1000 |
Massive MIMO
Massive multiple-input multiple-output systems use large antenna arrays to increase capacity and spectral efficiency. They extend conventional MIMO by serving multiple users simultaneously and steering signals toward them to reduce interference.Beamforming
Beamforming directs radio energy toward specific users. In analogue beamforming, antenna outputs are combined to focus signal power in one direction. Digital beamforming transmits data streams across multiple layers to improve signal strength and reliability.Non-orthogonal multiple access (NOMA)
Non-orthogonal multiple access assigns different power levels to users sharing the same frequency resources to improve spectral efficiency.Channel coding
5G NR uses polar codes for control channels and low-density parity-check codes for data channels, replacing the turbo codes used in 4G.Research in to wireless power
Research has explored the use of 5G mmWave networks for wireless power transfer. Studies using wavelengths between 1 mm and 10 mm remain experimental.Core network architecture
The 5G core is a service-oriented, software-defined system that separates control and user planes and supports flexible deployment. It replaces the 4G Evolved Packet Core with modular, software-based network functions.Software-defined networking and virtualization
Software-defined networking and network function virtualization enable software-based configuration, scaling, and management of networks. Together with network slicing, these technologies support applications such as the Internet of things, connected vehicles, and industrial automation.Service-based architecture (SBA)
Service-based architecture integrates SDN and NFV principles and replaces the 4G EPC framework with modular network functions that communicate through RESTful APIs. Each function registers with a network repository function, which enables independent scaling and interoperability.Core network functions
Each network function performs a defined role within the 5G core, replacing or extending elements from the 4G EPC.| Function | Acronym | 4G equivalent |
| Authentication server function | AUSF | MME; HSS |
| Access and mobility management function | AMF | MME |
| Session management function | SMF | MME; PGW-C |
| User plane function | UPF | SGW-U; PGW-U |
| Policy control function | PCF | PCRF |
| Unified data management | UDM | HSS |
| Unified data repository | UDR | HSS database |
| Network exposure function | NEF | - |
| Network slice selection function | NSSF | - |
| Network data analytics function | NWDAF | - |
| Charging function | CHF | CSCF |
Supporting components
Additional components manage roaming and inter-network connectivity:- Non-3GPP Interworking Function
- Security Edge Protection Proxy
- Trusted Non-3GPP Gateway Function
- Trusted WLAN Interworking Function
- Wireline Access Gateway Function
Frequency bands and coverage
Between 2016 and 2019, regulators in many regions, including the United States and the European Union, reallocated large sections of spectrum for 5G through auctions and new licensing rules. By 2019, more than 50 countries had assigned or planned to assign 5G frequencies. In 3GPP Release 16, the standard added 5G NR-U, allowing operation in unlicensed as well as licensed spectrum.
Frequency ranges
The 5G New Radio interface defines two main operating ranges:- Frequency Range 1 – below 7.125 GHz, also called sub-6 GHz. It covers low- and mid-band frequencies and supports channel bandwidths up to 100 MHz. Typical download speeds range from 5 to 900 Mbit/s depending on conditions.
- Frequency Range 2 – 24–71 GHz, known as millimeter wave or high band. It supports wider channel bandwidths—up to 400 MHz per carrier—and can reach multi-gigabit data rates. These signals travel only short distances and are easily blocked by walls, windows, and vegetation, so FR2 is mainly used in dense urban areas such as stadiums and city centers.