Fifth Generation of Mobile Telecommunications
5G (short for 5th Generation) is a commonly used term for certain advanced wireless systems. Industry association 3GPP defines any system using “5G NR” (5G New Radio) software as “5G”, a definition that came into general use by late 2018. Others may reserve the term for systems that meet the requirements of the ITU IMT-2020, which represents more nations. 3GPP will submit their 5G NR to the ITU. It follows 2G, 3G and 4G and their respective associated technologies (Like GSM, UMTS, LTE, LTE Advanced Pro, etc.)
The first fairly substantial deployments were in April 2019. In South Korea, SK Telecom claimed 38,000 base stations, KT Corporation 30,000 and LG U Plus 18,000. 85% are in six major cities. They are using 3.5 GHz (sub-6) spectrum and tested speeds were from 193 to 430 Mbit/s down.
Verizon opened service on a very limited number of base stations in the US cities of Chicago and Minneapolis using 400 MHz of 28 GHz millimeter wave spectrum. Download speeds in Chicago were from 80 to 634 Mbit/s. Upload speeds were from 12 to 57 Mbit/s. Ping was 25 milliseconds.
5G networks are digital cellular networks, in which the service area covered by providers is divided into a mosaic of small geographical areas called cells. Analog signals representing sounds and images are digitized in the phone, converted by an analog to digital converter and transmitted as a stream of bits. All the 5G wireless devices in a cell communicate by radio waves with a local antenna array and low power automated transceiver (transmitter and receiver) in the cell, over frequency channels assigned by the transceiver from a common pool of frequencies, which are reused in geographically separated cells. The local antennas are connected with the telephone network and the Internet by a high bandwidth optical fiber or wireless backhaul connection. Like existing cellphones, when a user crosses from one cell to another, their mobile device is automatically “handed off” seamlessly to the antenna in the new cell.
Millimeter waves have shorter range than microwaves, therefore the cells are limited to smaller size; The waves also have trouble passing through building walls, requiring multiple antennas to cover a cell. Millimeter wave antennas are smaller than the large antennas used in previous cellular networks, only a few inches (several cm) long Another technique used for increasing the data rate is massive MIMO (multiple-input multiple-output). Each cell will have multiple antennas communicating with the wireless device, received by multiple antennas in the device, thus multiple bitstreams of data will be transmitted simultaneously, in parallel. In a technique called beamforming the base station computer will continuously calculate the best route for radio waves to reach each wireless device, and will organise multiple antennas to work together as phased arrays to create beams of millimeter waves to reach the device.
The new 5G wireless devices also have 4G LTE capability, as the new networks use 4G for initially establishing the connection with the cell, as well as in locations where 5G access is not available.
5G can support up to a million devices per square kilometer, while 4G supports only 4000 devices per square kilometer.
The ITU-R has defined three main types of uses that the capability of 5G is expected to enable. They are Enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communications (URLLC), and Massive Machine Type Communications (mMTC). Enhanced Mobile Broadband (eMBB) refers to using 5G as an evolution to 4G LTE mobile broadband services with faster connections, higher throughput, and more capacity. Ultra-Reliable Low-Latency Communications (URLLC) refer to using the network for mission critical applications that requires uninterrupted and robust data exchange. Massive Machine-Type Communications (mMTC) refers to the type of usage that connect to large number of low power, low cost device in a wide area which have high requirements on scalability and increased battery lifetime.
5G NR speed in sub-6 GHz bands can be slightly higher than the 4G with a similar amount of spectrum and antennas, though some 3GPP 5G networks will be slower than some advanced 4G networks, such as T-Mobile’s LTE/LAA network, which achieves 500+ Mbit/s in Manhattan. The 5G specification allows LAA (License Assisted Access) as well but it has not yet been demonstrated. Adding LAA to an existing 4G configuration can add hundreds of megabits per second to the speed, but this is an extension of 4G, not a new part of the 5G standard.
Speeds in the less common millimetre wave spectrum can be substantially higher. Early testing on Verizon’s 5G millimeter wave system showed speeds of 200-634 Mbit/s using 400 MHz of spectrum. See above for more recent data.
In 5G, the latency target for Ultra-Reliable Low-Latency Communication (URLLC) scenario is 1-millisecond, while the latency target for the enhanced mobile broadband (eMBB) scenario is 4-millisecond. As a comparison, it is difficult to get less than 20 ms latency for certain in 4G LTE network especially when there are large amount of concurrent connections.
Initially, the term was associated with the International Telecommunication Union‘s IMT-2020 standard, which required a theoretical peak download capacity of 20 gigabits, along with other requirements. Then, the industry standards group 3GPP chose the 5G NR (New Radio) standard together with LTE as their proposal for submission to the IMT-2020 standard.
The first phase of 3GPP 5G specifications in Release-15 is scheduled to complete in 2019. The second phase in Release-16 is due to be completed in 2020.
5G NR can include lower frequencies (FR1), below 6 GHz, and higher frequencies (FR2), above 24 GHz. However, the speed and latency in early FR1 deployments, using 5G NR software on 4G hardware (non-standalone), are only slightly better than new 4G systems, estimated at 15 to 50% better.
IEEE covers several areas of 5G with a core focus in wireline sections between the Remote Radio Head (RRH) and Base Band Unit (BBU). The 1914.1 standards focus on network architecture and dividing the connection between the RRU and BBU into two key sections. Radio Unit (RU) to the Distributor Unit (DU) being the NGFI-I (Next Generation Fronthaul Interface) and the DU to the Central Unit (CU) being the NGFI-II interface allowing a more diverse and cost-effective network. NGFI-I and NGFI-II have defined performance values which should be compiled to ensure different traffic types defined by the ITU are capable of being carried. 1914.3 standard is creating a new Ethernet frame format capable of carrying IQ data in a much more efficient way depending on the functional split utilized. This is based on the 3GPP definition of functional splits. Multiple network synchronization standards within the IEEE groups are being updated to ensure network timing accuracy at the RU is maintained to a level required for the traffic carried over it.
5G NR (New Radio) is a new air interface developed for the 5G network. It is supposed to be the global standard for the air interface of 5G networks.
- 5GTF: The 5G network implemented by American carrier Verizon for Fixed Wireless Access in late 2010s uses a pre-standard specification known as 5GTF (Verizon 5G Technical Forum). The 5G service provided to customers in this standard is incompatible with 5G NR. There are plans to upgrade 5GTF to 5G NR “Once [it] meets our strict specifications for our customers,” according to Verizon.
- 5G-SIG： Pre-standard specification of 5G developed by KT Corporation. Deployed at Pyeongchang 2018 Winter Olympics.
Beyond mobile operator networks, 5G is also expected to be widely utilized for private networks with applications in industrial IoT, enterprise networking, and critical communications.
Initial 5G NR launches will depend on existing LTE (4G) infrastructure in non-standalone (NSA) mode (5G NR software on LTE radio hardware), before maturation of the standalone (SA) mode (5G NR software on 5G NR radio hardware) with the 5G core network.
As of April 2019, the Global Mobile Suppliers Association had identified 224 operators in 88 countries that are actively investing in 5G (i.e. that have demonstrated, are testing or trialling, or have been licensed to conduct field trials of 5G technologies, are deploying 5G networks or have announced service launches). The equivalent numbers in November 2018 were 192 operators in 81 countries. The first country to adopt 5G on a large scale was South Korea, in April 2019.
When South Korea launched its 5G network, all carriers used Samsung, Ericsson and Nokia base stations and equipment, except for LG U Plus, who also used Huawei equipment. Samsung was the largest supplier for 5G base stations in South Korea at launch, having shipped 53,000 base stations at the time, out of 86,000 base stations installed across the country at the time.
In order to support increased throughput requirements of 5G, large quantities of new spectrum (5G NR frequency bands) have been allocated to 5G. For example, in July 2016, the Federal Communications Commission (FCC) of the United States freed up vast amounts of bandwidth in underutilised high-band spectrum for 5G. The Spectrum Frontiers Proposal (SFP) doubled the amount of millimeter-wave unlicensed spectrum to 14 GHz and created four times the amount of flexible, mobile-use spectrum the FCC had licensed to date. In March 2018, European Union lawmakers agreed to open up the 3.6 and 26 GHz bands by 2020.
As of March 2019, there was reported to be 52 countries, territories, special administrative regions, disputed territories and dependencies that are formally considering introducing certain spectrum bands for terrestrial 5G services, are holding consultations regarding suitable spectrum allocations for 5G, have reserved spectrum for 5G, have announced plans to auction frequencies or have already allocated spectrum for 5G use.
In March 2019, the Global Mobile Suppliers Association released the industry’s first database tracking worldwide 5G device launches. In it, the GSA identified 23 vendors who have confirmed the availability of forthcoming 5G devices with 33 different devices including regional variants. There were seven announced 5G device form factors: (phones (x12 devices), hotspots (x4), indoor and outdoor CPE (x8), modules (x5), Snap-On dongles and adapters (x2) and USB terminals (x1).
In the 5G IoT chipset arena, as of April 2019 there were four commercial 5G modem chipsets and one commercial processor/platform, with more launched expected in the near future.
In April, 2019, the city of Brussels blocked a 5G trial because of radiation fears. Since 2018 there have been groups which have opposed the deployment of 5G, citing health concerns. Most authorities do not believe there is conclusive evidence of harm.
The U.S. has urged its allies not to use Chinese equipment (from ZTE and Huawei), over fears of espionage on foreign users. The US fears that the Chinese government may force Huawei to incorporate software backdoors or hardware that would allow China to spy on the U.S. or its allies and intervene in industries like power, transportation and manufacturing. The US has threatened to withdraw some co-operations with its allies if they install Huawei equipment on telecommunication networks. The ambassador for cyber and international communications at the U.S. State Department Robert Strayer, said at the Mobile World Congress 2019 that “The United States is asking other governments and the private sector to consider the threat posed by Huawei and other Chinese information technology companies.”
US Senator Marco Rubio said:
Another US Senator, Mark Warner, said:
2 Chinese laws are of concern: the 2017 National Intelligence Law and the 2014 Counter-Espionage Law. The National Intelligence Law states that: “any organization or citizen shall support, assist and cooperate with the state intelligence work in accordance with the law”, and that China will protect any organization or individual that helps the Chinese government. The 2014 Counter-Espionage law states that: “when the state security organ investigates and understands the situation of espionage and collects relevant evidence, the relevant organizations and individuals shall provide it truthfully and may not refuse.” Despite this, Huawei continues to state that “Huawei will not build backdoors or hand over customer data … We have never been required to do so.”
Huawei has encouraged the US to present evidence to sustain its espionage fears. Huawei founder Ren Zhengfei, claims that the US sees 5G like if it were a nuclear bomb, a strategic weapon, and that the US’ concerns are politically motivated, because the US does not want to stop being the world leader in technology. He also said that if the west does not want a second Cold War, it must stay open and accept the rise of new countries (like China). Ren said that his company is willing to advice the Chinese government to sign Germany’s agreement against espionage. He later told Germany’s interior minister that Huawei is willing to sign that agreement with the German government and that Huawei will not secretly install surveillance equipment on Germany’s 5G network. Ren also stated in an interview that Huawei would never help China spy on the United States, even if required by law. He also said that his membership to the Chinese Communist Party would not affect his ability to deny the Chinese government access to user data, emphasizing that Huawei would never allow China’s government to access customer data, even if requested by the Chinese government, that Huawei has never handed user data to the Chinese government, and that “China’s ministry of foreign affairs has officially clarified that no law in China requires any company to install mandatory back doors. Huawei and me personally have never received any request from any government to provide improper information”. He continued, saying “When it comes to cybersecurity and privacy protection we are committed to be sided with our customers. We will never harm any nation or any individual.”
In a speech at the Mobile World Congress (MWC) 2019, Huawei’s Rotating Chairman Guo Ping said:
In a Financial Times editorial, Ping said that his company “hampers US efforts to spy on whomever it wants,” and once again said that “Huawei has not and will never plant backdoors.”
Huawei’s security manager John Suffolk, said that Huawei allows its software to be inspected, but that they will not open source it for review from other third parties because 5G is Huawei’s “Crown Jewel”. He also said that the company would be as open as possible and that the US would not be a leader in 5G due to the exclusion of Huawei equipment in the US.
Huawei denies that they have ties to the Chinese government, saying that it would “categorically refuse” any requests for data from the Chinese government. There are concerns that the Chinese government has too much influence over companies like Huawei and ZTE. Huawei denies any criminal wrongdoing.
Houlin Zhao, secretary general of the International Telecommunication Union, a branch of the United Nations, suggested that US allegations are politically motivated.
Some countries like Australia, have banned network operators from using Huawei or ZTE equipment. Australia highlighted the fact that Chinese internet laws require technology companies to help the Chinese government with “intelligence work,” meaning companies could be forced to hand over network data. Other countries like Japan have cited security concerns and have successfully persuaded carriers to exclude Huawei or ZTE equipment in their 5G networks, without officially banning their use.
According to Miyagawa Jyunichi, Chief Technology Officer of the Japanese carrier Softbank, the mechanism behind 4G and 5G base stations is different. In a 4G core network, data is encrypted and transmitted using a tunneling protocol, which makes it difficult to extract communication data from the network. However, in a 5G network, if technology like Mobile Edge Computing is used, processing servers could be placed near base stations, in order to enable information processing on the base station side of the carrier network. In other words, information transmitted via a 5G network could be decrypted for processing at the base station and this makes it possible to extract communication (user) data via these servers, which would make espionage possible, and espionage fears understandable.
In South Korea, LG U+ (LG U Plus) is the only carrier to have adopted Huawei equipment in their 5G network, unlike the other two carriers that have rejected Huawei for security reasons. It is reported that LG U+ is trying to narrow its market share gap with the two other leading carriers by using Huawei equipment, which costs less. LG U Plus does not believe that there are problems in the security of Huawei equipment, which has resulted in boycott movements against the carrier for their perceived negligence in security by choosing Huawei as its supplier.
It is reported that the South Korean government is not willing to ban Huawei equipment because they are fearful of another economic revenge by China like what happened during the deployment of THAAD.
Germany has increased security requirements for manufacturers interested in Germany’s 5G network and the German Interior Ministry says that any company providing “core componentry for critical infrastructure” will need to sign a “declaration of trustworthiness”, after which its equipment will undergo a thorough security check. This follows an incident on which corporate secrets from ASML Holding (a Dutch company that makes photolithography equipment for making microchips) were allegedly stolen by XTAL, a company with links to the Chinese government. Despite the fact that ASML denies being victim of Chinese espionage, this incident is growing suspicions in Europe about the Chinese government and its intentions.
According to German intelligence agents, because of the complexity of 5G networks, weekly security updates to 5G equipment software will be necessary, and it will be impossible for test centers to check all these updates on time before they are released and implemented into equipment.
Intelligence experts have been skeptical about Huawei’s independence claims, citing Chinese laws that require local companies to assist the Chinese government in intelligence gathering when the Chinese communist party requests it. Academic researchers question Huawei’s claims of independence from the Chinese government, because Huawei is majority owned by a committee of its trade union, but trade unions in China have to follow instructions from and represent the ruling Chinese Communist Party.
The air interface defined by 3GPP for 5G is known as New Radio (NR), and the specification is subdivided into two frequency bands, FR1 (below 6 GHz) and FR2 (mmWave), each with different capabilities.
The maximum channel bandwidth defined for FR1 is 100 MHz, due to the scarcity of continuous spectrum in this crowded frequency range. The band most widely being used for 5G in this range is around 3.5 GHz. The Korean carriers are using 3.5 GHz although some millimeter wave spectrum has also been allocated.
The minimum channel bandwidth defined for FR2 is the 50 MHz and the maximum is 400 MHz, with two-channel aggregation supported in 3GPP Release 15. In the U.S., Verizon is using 28 GHz and AT&T is using 39 GHz. 5G can use frequencies of up to 300 GHz. The higher the frequency, the greater the ability to support high data transfer speeds without interfering with other wireless signals or becoming overly cluttered. Due to this, 5G can support approximately 1,000 more devices per meter than 4G.
5G can use higher frequencies than 4G, and as a result, some 5G signals are not capable of traveling large distances (over a few hundred meters), unlike 4G or lower frequency 5G signals. This requires placing 5G base stations every few hundred meters in order to utilize higher frequency bands. Also, these higher frequency 5G signals cannot easily penetrate solid objects, like cars, trees and walls, because of the nature of these higher frequency electromagnetic waves.
|5G on FR2 base station types
|Deployment environment||Max. number
|Max. distance from
|Femto cell||Homes, businesses||Home: 4−8
|10s of meters|
|Pico cell||Public areas like shopping malls,
airports, train stations, skyscrapers
|64 to 128||indoors: 100−250
|10s of meters|
|Micro cell||Urban areas to fill coverage gaps||128 to 256||outdoors: 5000−10000||few 100s of meters|
|Metro cell||Urban areas to provide additional capacity||more than 250||outdoors: 10000−20000||100s of meters|
|Homes, businesses||less than 50||indoors: 20−100
|few 10s of meters|
Massive MIMO (multiple input and multiple output) antennas increases sector throughput and capacity density using large numbers of antennae and Multi-user MIMO (MU-MIMO). Each antenna is individually-controlled and may embed radio transceiver components. Nokia claimed a five-fold increase in the capacity increase for a 64-Tx/64-Rx antenna system. The term “massive MIMO” was coined by Nokia Bell Labs researcher Dr. Thomas L. Marzetta in 2010, and has been launched in 4G networks, such as Softbank in Japan.
Of over 562 separate 5G demonstrations, tests or trials globally of 5G technologies, at least 94 of them have involved testing Massive MIMO in the context of 5G.
Edge computing is delivered by cloud computing servers closer to the ultimate user. It reduces latency and data traffic congestion.
Small cells are low-powered cellular radio access nodes that operate in licensed and unlicensed spectrum that have a range of 10 meters to a few kilometers. Small cells are critical to 5G networks, as 5G’s radio waves can’t travel long distances, because of 5G’s higher frequencies.
Beamforming, as the name suggests, is used to direct radio waves to a target. This is achieved by combining elements in an antenna array in such a way that signals at particular angles experience constructive interference while others experience destructive interference. This improves signal quality and data transfer speeds (because of the improved signal quality) 5G uses beamforming.
One expected benefit of the transition to 5G is the convergence of multiple networking functions to achieve cost, power and complexity reductions. LTE has targeted convergence with Wi-Fi band/technology via various efforts, such as License Assisted Access (LAA; 5G signal in unlicensed frequency bands that are also used by Wi-Fi) and LTE-WLAN Aggregation (LWA; convergence with Wi-Fi Radio), but the differing capabilities of cellular and Wi-Fi have limited the scope of convergence. However, significant improvement in cellular performance specifications in 5G, combined with migration from Distributed Radio Access Network (D-RAN) to Cloud- or Centralized-RAN (C-RAN) and rollout of cellular small cells can potentially narrow the gap between Wi-Fi and cellular networks in dense and indoor deployments. Radio convergence could result in sharing ranging from the aggregation of cellular and Wi-Fi channels to the use of a single silicon device for multiple radio access technologies.
NOMA (non-orthogonal multiple access) is a proposed multiple-access technique for future cellular systems. In this, same time, frequency, and spreading-code resources are shared by the multiple users via allocation of power. The entire bandwidth can be exploited by each user in NOMA for entire communication time due to which latency has been reduced and users’ data rates can be increased. For multiple access, the power domain has been used by NOMA in which different power levels are used to serve different users. 3GPP also included NOMA in LTE-A due to its spectral efficiency and is known as multiuser superposition transmission (MUST) which is two user special case of NOMA.
Initially, cellular mobile communications technologies were designed in the context of providing voice services and Internet access. Today a new era of innovative tools and technologies is inclined towards developing a new pool of applications. This pool of applications consists of different domains such as the Internet of Things (IoT), web of connected autonomous vehicles, remotely controlled robots, and heterogeneous sensors connected to serve versatile applications.
Like LTE in unlicensed spectrum, 5G NR will also support operation in unlicensed spectrum (NR-U). In addition to License Assisted Access (LAA) from LTE that enable carriers to use those unlicensed spectrum to boost their operational performance for users, in 5G NR it will support standalone NR-U unlicensed operation which will allow new 5G NR networks to be established in different environments without acquiring operational license in licensed spectrum, for instance for localized private network or lower the entry barrier for providing 5G internet services to the public.