5G is the 5th generation mobile network.

It is a new global wireless standard after 1G, 2G, 3G, and 4G networks. 5G enables a new kind of network that is designed to connect virtually everyone and everything together including machines, objects, and devices.

5G wireless technology is meant to deliver higher multi-Gbps peak data speeds, ultra low latency, more reliability, massive network capacity, increased availability, and a more uniform user experience to more users.

While earlier generations of cellular technology (such as 4G LTE) focused on ensuring connectivity, 5G takes connectivity to the next level by delivering connected experiences from the cloud to clients.

 5G networks are virtualized and software-driven, and they exploit cloud technologies.

The 5G network will also simplify mobility, with seamless open roaming capabilities between cellular and Wi-Fi access. Mobile users can stay connected as they move between outdoor wireless connections and wireless networks inside buildings without user intervention or the need for users to reauthenticate. 

The new Wi-Fi 6 wireless standard (also known as 802.11ax) shares traits with 5G, including improved performance. Wi-Fi 6 radios can be placed where users need them to provide better geographical coverage and lower cost.

Underlying these Wi-Fi 6 radios is a software-based network with advanced automation.

5G technology should improve connectivity in underserved rural areas and in cities where demand can outstrip today’s capacity with 4G technology.

New 5G networks will also have a dense, distributed-access architecture and move data processing closer to the edge and the users to enable faster data processing.

How does 5G technology work ?

5G technology will introduce advances throughout network architecture.

5G New Radio, the global standard for a more capable 5G wireless air interface, will cover spectrums not used in 4G.

New antennas will incorporate technology known as massive MIMO (multiple input, multiple output), which enables multiple transmitters and receivers to transfer more data at the same time.

But 5G technology is not limited to the new radio spectrum. It is designed to support a converged, heterogeneous network combining licensed and unlicensed wireless technologies.

This will add bandwidth available for users.

5G architectures will be software-defined platforms, in which networking functionality is managed through software rather than hardware.

Advancements in virtualization, cloud-based technologies, and IT and business process automation enable 5G architecture to be agile and flexible and to provide anytime, anywhere user access.

5G networks can create software-defined subnetwork constructs known as network slices. These slices enable network administrators to dictate network functionality based on users and devices.

5G also enhances digital experiences through machine-learning (ML)-enabled automation. Demand for response times within fractions of a second (such as those for self-driving cars) require 5G networks to enlist automation with ML and, eventually, deep learning and artificial intelligence (AI).

Automated provisioning and proactive management of traffic and services will reduce infrastructure cost and enhance the connected experience.

Frequency Spectrum – 5G NR (New Radio)

The 5G networks will work with within several different frequency bands (Table 1), of which the lower frequencies are being proposed for the first phase of the 5G networks.

Several of these frequencies (principally below 1 GHz; Ultra-high frequencies, UHF) have actually been or are presently used for earlier mobile communication generations. Furthermore, much higher radio frequencies (RF) are also planned to be used at later stages of technology evolutions.

The new bands are well above the UHF ranges, having wavelengths in the centimeter (3–30 GHz) or the millimeter ranges (30–300 GHz; millimeter waves, MMW).

These latter bands have traditionally been used for radars and microwave links.

Table 1 – Subdivision of the 5G frequency spectrum.

Frequency Range	Use	Comments
<1 GHz	Net coverage, IoT	Already partly used for earlier MP generations, longer range coverage, less costly infrastructure
1–6 GHz	Net coverage, IoT, capacity for data transfer	More spectrum available, shorter range and reduced performance compared to higher frequencies
>6 GHz	Capacity for very high data transfer	Short range, allows high speed data transfer and short latency times

Conventional 3G and 4G cellular networks transmit signals below 3.6 GHz of radio frequency spectrum.

Due to bandwidth limitations, maximum data rate has limitations as well.

5G tests have confirmed that the technology is capable of achieving downlink data rate up to few gigabits per second.

The goal of 5G technologies, however, goes beyond merely serving mobile broadband, but offers key improvements that enable a much wider range of applications: enhanced mobile broadband (eMBB), ultra-reliable and low latency communications (URLLC), massive machine-type communications (MMC), and fixed wireless access (FWA).

Enhanced Mobile Broadband (eMBB)

Where 5G eMBB differs from 4G mobile broadband are 5G’s extreme data rates and ubiquitous urban coverage goals. With eMBB the IMT-2020 goals are to provide standard that facilitate peak download speeds to 20 Gbps, and reliable user data rates in urban environments of at least 100 Mbps with only 4 ms latency.

Though current 4G mobile broadband speeds can reach peak speeds of hundreds of megabits per second, most urban users experience less than 10 Mbps speeds with latencies in the tens of milliseconds.

Beyond rapid video downloads, 5G eMBB will enable use cases that open the door to augmented reality and virtual reality applications in real-time, throughout and urban environment.

This performance requires upgrades throughout the cellular networking stack, as well as technology enhancements for handsets. Much of the change in network architecture is currently happening, as major telecom companies are deploying more small cells to enable eMBB performance, where traditional homogeneous macro-cell architectures have proven incapable, especially in densely cluttered urban environments.

Ultra-reliable and Low Latency Communications (URLLC)

Though some areas experience cellular wireless performance that can be considered enterprise grade, most current cellular systems aren’t able to provide the reliability or latency requirements for critical applications, such as autonomous vehicles, mobile healthcare, factory automation, or emergency response.

5G URLLC aims to provide highly reliable, secure, and low latency communications that provide sub-1ms latency communications solid enough for use in applications that could mean life or death.

Enhancing cellular network reliability and reducing latency involves changes with how cellular handset, base station, and networking is done.

These enhancements include new waveforms, lower latency hardware, and likely wireless networking approaches that enable frequency-agility, redundancy, and alternative network architecture types than a star network.

Massive Machine-type Communications (MMC)

Most cellular wireless users today are individuals using mobile handsets, but future cellular networks will likely be dominated by Internet of Things (IoT) devices intercommunicating, reporting sensor information, and acting on control data throughout modernized urban areas, factories, industrial installations, and transportation networks.

Much, and maybe the majority, of future cellular communications will be between machines, which pose very different requirements than human users.

Dispersed IoT and machine devices are likely to require a very diverse range of communication requirements, making a single one-size-fits-all wireless communication protocol inviable.

Hence, the new 5G standards are likely to include adaptable communication protocol methods, so that systems such as battery operated sensors with low-power and low-data rate requirements can use the same network technology as high-data rate and low-latency autonomous robots, for example.

Previously cellular generations relied on using specific frequency bands for certain applications, which is less likely to be the solution for future cellular generations as spectrum congestion leads makes each frequency band more valuable.

Fixed Wireless Access (FWA)

Though sparsely used, 3G and 4G cellular networks have supported a range of pseudo-fixed wireless access systems, with hotspots and cellular modems. However, the enhanced data rate and low latency capability of 5G networks enables an attractive business use case of providing FWA to compete with other last-mile internet service.

With greater bandwidth and advanced antenna technologies, many experts predict that 5G networks will be able to provide fiber-like performance and enable developed and developing markets with accessible internet and connectivity.

Beyond massive multi-input multi-output (mMIMO) and beamforming capable antennas, FWA services also require bandwidth beyond what is available in the sub-6 GHz spectrum driving current cellular networkings.

Large amounts of bandwidth, likely exceeding 1 GHz, will be necessary to provide fiber-like service.

Hence, 5G cellular networks are including millimeter-wave frequency bands to enable new applications and dramatic increases in data rates compared to previously generations.

5G Frequencies Compared to 4G Frequencies

Early GSM cellular networks operated at 850 MHz and 1900 MHz. 2G and 3G networks change the modulation method but largely used the same portions of the spectrum with reorganized frequency bands.

As 3G evolved, additional frequency bands were included as well as spectrum around 2100 MHz. 4G LTE technologies brought it additional spectrum and frequency bands, namely around 600 MHz, 700 MHz, 1.7/2.1 GHz, 2.3 GHz, and 2.5 GHz. All of the previous cellular network frequencies are based on licenses (Table 1).

The 5G frequency band plans are much more complex, as the frequency spectrum for sub-6 GHz 5G spans 450 MHz to 6 GHz, and millimeter-wave 5G frequencies span 24.250 GHz to 52.600 GHz, and also include unlicensed spectrum.

Additionally, there may be 5G spectrum in the 5925 to 7150 MHz range and 64 GHz to 86 GHz range. Therefore, 5G will include all previous cellular spectrum and a large amount spectrum in the sub-6 GHz range, and beyond sub- 6 GHz is many times current cellular spectrum (Table 2 and Table 3).

The initial 3GPP release of 5G New Radio Non-standalone (5G NR) standards included several sub-6 GHz frequency bands, designated FR1.

The second 3GPP 5G release after IMT-2020 will include FR2 frequency bands in the millimeter-wave spectrum .

As with previous cellular generations and 3GPP releases, various regions and countries will also likely adopt unique spectrum for 5G uses.

The US FCC, for example, is considering opening 5.925 GHz to 6.425 GHz and 6.425 GHz to 7.125 GHz  for unlicensed used and is consulting adding mobile broadband capability in the 3.7 GHz to 4.2 GHz spectrum.

Currently, the FCC is actioning spectrum in the 27.5 GHz to 28.35 GHz, 24.25 GHz to 24.45 GHz, and 24.75 GHz 25.25 GHz, range for millimeter-wave 5G use.

The FCC may also be considering opening 3.7 GHz to 4.2 GHz mid-band frequencies for 5G, and may also be considering opening 4.9 GHz public safety bands for 5G access.

Moreover, the FCC may also make additional bands available for 5G in the 2.75 GHz, 26 GHz, and 42 GHz bands.

In December 2018 the FCC announced an incentive action in the 37.6 GHz to 38.6 GHz, 38.6 GHz to 40 GHz, and 47.2 GHz to 48.2 GHz. Most other developing countries are undergoing similar considerations of spectrum allocation for 5G use cases.

One of the main reasons that additional spectrum is being made available for 5G uses, is the physical limitations associated with throughput and bandwidth.

4G band plans accounted for between 5 MHz and 20 MHz of bandwidth per channel, where the 5G FR1 standard allows for between 5 MHz and 100 MHz of bandwidth per channel. As bandwidth is directly proportional to maximum throughput, the 5X increase in bandwidth relates to roughly a 5X increase in throughput.

Moreover, 3GPP Release 15 established new waveforms and the addition of π/2 BPSK as a modulation method.

The additional waveforms are discrete fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) for FR1 and cyclic prefix OFDM (CP-OFDM) for FR2.

Though RF hardware, technology, and the communications infrastructure are available and capable of meeting some of the requirements of early 5G frequency and performance specifications, the majority of 5G expectations are still beyond currently accessible technologies.

These challenges include cost effective hardware with the necessary frequency operation, handheld/mobile integration, and dense and highly distributed networking infrastructure.

With 4G LTE services still being deployed throughout the US and other countries, it will likely be several years before 5G services beyond FR1 5G capabilities are viable.

 Now, we offer a view into 5G NR massive MIMO and how this technology delivers improvements for both mobile device users and networks.

MIMO gets massive

MIMO systems require a combination of antenna expansion and complex algorithms. It’s multifaceted, but MIMO has been used in wireless communications for a long time now — it’s common for both mobile devices and networks to have multiple antennas to enhance connectivity and offer better speeds and user experiences. MIMO algorithms come into play to control how data maps into antennas and where to focus energy in space. Both network and mobile devices need to have tight coordination among each other to make MIMO work.

Now, with the design of new 5G NR networks, MIMO becomes “massive” and crucial for 5G NR deployments.

Massive MIMO — which is an extension of MIMO — expands beyond the legacy systems by adding a much higher number of antennas on the base station. The “massive” number of antennas helps focus energy, which brings drastic improvements in throughput and efficiency. Along with the increased number of antennas, both the network and mobile devices implement more complex designs to coordinate MIMO operations. That’s all to say, these advancements are all aimed at achieving performance improvements needed to underpin the 5G experiences consumers expect in this new era.

Demystifying massive MIMO technology

Let’s dive deeper into the building blocks of MIMO systems.

They capitalize on three key concepts, which are spatial diversity, spatial multiplexing, and beamforming:    

Spatial diversity and spatial multiplexing

Spatial diversity is one of the fundamental benefits of MIMO technology. In brief, diversity aims at improving the reliability of the system by sending the same data across different propagation, or spatial, paths.

Spatial diversity evolves into a more complex concept, which is “spatial multiplexing.”

Now, not only are the diverse experiences of the over-air-channel utilized for performance improvements, but multiple messages can be transmitted simultaneously without interfering with one another since they are separated in space.

To better visualize the concept of spatial multiplexing, think of a pipeline through which data is flowing between the base station and the phone on a mobile network.

Envision a situation with one antenna on the base station and one on the phone – that allows for only so much data to flow.

Now, by installing more antennas on either side with proper spatial separation (see illustration below), multiple virtual pipelines can be created in the space between phone and the base station. This creates multiple paths for more data to travel between the base station and mobile.

By nature, this solution is very dynamic. With the continuous movement of the mobile user and changes in the surrounding environment, the mobile phone and the network require more advanced capabilities to continuously coordinate the link and manage the data transmission.

Beamforming

Beamforming is another key wireless technique that utilizes advanced antenna technologies on both mobile devices and networks’ base stations to focus a wireless signal in a specific direction, rather than broadcasting to a wide area.

Think of the difference between using a flashlight — which kind of floods everyone in the room — versus a laser pointer, which can pinpoint and continuously track a given user.

With the massive number of antenna elements in a massive MIMO system, beamforming becomes “3D Beamforming.”

3D Beamforming creates horizontal and vertical beams toward users, increasing data rates (and capacity) for all users — even those located in the top floors of high-rise buildings (see illustration below).

Mobile feedbacks to the network, allow the network’s beam to find any point in space, so a mobile user can always be served by a focused beam to their devices, as they are moving on the street or between different floors in a building.

Also having such narrow, direct beams reduces interference between beams directed in different directions.    

Multi-User MIMO

But wait there’s more: MIMO technology also allows multiple users to share the same network resources, simultaneously.

Multi-User MIMO or “MU-MIMO” allows messages for different users to travel securely along the same data pipelines, then be sorted to individual users when the data arrives at their mobile devices.

Think of it as similar to your online shopping order traveling in a delivery van along with other orders. Your order shares space in the van, yet only gets delivered to you — the intended recipient.

Serving multiple users with same transmission increases capacity and allows for better utilization of resources. That adds up to the ability to download or stream with an improved experience for the user even in crowded area.

This shared transportation of data means a faster and more efficient system for all users (see illustration below). That adds up to the ability to download or stream with an improved experience for the user, even in crowded areas.

Also, networks can dynamically switch between serving one or multiple users.

When a single user is served, typically the beam is more direct and power is more focused. However, with multiple users, beams tend to be wider as users may scatter in various directions.

Benefits of massive MIMO

Massive MIMO is a key enabler of 5G’s extremely fast data rates and promises to raise 5G’s potential to a new level. The primary benefits of massive MIMO to the network and end users can be summed up as:

• Increased Network Capacity – Network Capacity is defined as the total data volume that can be served to a user and the maximum number of users that can be served with certain level of expected service. Massive MIMO contributes to increased capacity first by enabling 5G NR deployment in the higher frequency range in Sub-6 GHz (e.g., 3.5 GHz); and second by employing MU-MIMO where multiple users are served with the same time and frequency resources.
• Improved Coverage – With massive MIMO, users enjoy a more uniform experience across the network, even at the cell’s edge – so users can expect high data rate service almost everywhere. Moreover, 3D beamforming enables dynamic coverage required for moving users (e.g., users traveling in cars or connected cars) and adjusts the coverage to suit user location, even in locations that have relatively weak network coverage.
• User experience – Ultimately, the above two benefits result in a better overall user experience — users can transfer large data files or download movies, or use data-hungry apps on the go, wherever life takes them.

As mentioned earlier, MIMO has been used in wireless communications for many years. But now, in the context of 5G NR, massive MIMO is radically changing how and when we choose to use our mobile devices. We no longer have to second guess if we’re in a good area to download or transfer large files. The user experience is about to take an immense leap forward.

Massive MIMO is just one example of the many breakthrough inventions we have brought forth from decades of research and development to unlock 5G for the mobile industry and beyond, and transform how the world computes, connects and communicates. 

5G and EMF Safety

Are there safety limits for 5G and radio waves?

Yes. Comprehensive international guidelines exist governing exposure to radio waves including the frequencies proposed for 5G. The limits have been established by independent scientific organizations, such as the International Commission on Non-Ionizing Radiation Protection (ICNIRP), and include substantial margins of safety to protect all people against all established hazards.

These guidelines have been widely adopted in standards around the world, and are endorsed by the World Health Organization (WHO).

What do the experts say about 5G and health?

In relation to radio frequency exposures and wireless technology and health, the general conclusion from the World Health Organization (WHO) is:

“Despite extensive research, to date there is no evidence to conclude that exposure to low level electromagnetic fields is harmful to human health”

WHO – About Electromagnetic Fields – Summary of Health Effects Key Point 6

In relation to wireless networks and health, the conclusion from the WHO is:

“Considering the very low exposure levels and research results collected to date, there is no convincing scientific evidence that the weak RF signals from base stations and wireless networks cause adverse health effects”

Source WHO Backgrounder on base stations and wireless technologies

On mobile phone safety the World Health Organization advises:

“A large number of studies have been performed over the last two decades to assess whether mobile phones pose a potential health risk. To date, no adverse health effects have been established as being caused by mobile phone use.”

“While an increased risk of brain tumors is not established, the increasing use of mobile phones and the lack of data for mobile phone use over time periods longer than 15 years warrant further research of mobile phone use and brain cancer risk. In particular, with the recent popularity of mobile phone use among younger people, and therefore

a potentially longer lifetime of exposure, WHO has promoted further research on this group. Several studies investigating potential health effects in children and adolescents are underway.”

WHO Fact Sheet 193 June 2014 – Electromagnetic fields and public health: mobile phones

What research into health effects has been done on 5G?

The electromagnetic frequencies used for 5G are part of the radio frequency spectrum which has been extensively researched in terms of health impacts for decades. Over 50 years of scientific research has already been conducted into the possible health effects of the radio signals used for mobile phones, base stations and other wireless services including frequencies planned for 5G and mmWave exposures.

The data from this research has been analysed by many expert review groups. Weighing the whole body of science, there is no evidence

to convince experts that exposure below the guidelines set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) carries any known health risks, for adults or children.

The EMF-Portal (www.emf-portal.org) is an open-access extensive database of scientific research into the effects of EMF, including studies on the effects of RF on health. It is managed by the RWTH Aachen University, Germany and linked from the WHO website. EMF-Portal contains more than 25,000 published scientific articles on the biological and health effects of EMF and 2,500 studies on mobile communications.

In terms of research specifically on 5G frequencies, the database lists approximately 350 studies on mmWave EMF health related research. Extensive research on mmWave and health has been conducted on radar, microwave and military applications.

Is the research on 5G, mmWave and health continuing?

Yes – the current research on mmWave frequencies is focused on the alignment of the human exposure guidelines at frequencies below and above 6 GHz where the measurement parameter changes from Specific Absorption Rate (SAR) below 6 GHz to Power Density above 6 GHz.

For more on SAR see http://www.sartick.com/.

The research is also focused on the dielectric properties of human skin to ensure that the power density levels and averaging area across the skin align with the temperature values that are the basis of the human exposure guidelines.

For example, a mobile device operating at 5 GHz will be assessed for compliance by measuring the SAR. The SAR levels are set to limit the absorbed power so that the temperature rise in the head or body from the device operating at maximum power is below the equivalent relevant limit. If the same device was operating at 6.5 GHz, a power density measurement would be required, so the measurement parameters would need to ensure the same limit in temperature rise is maintained.

Will 5G devices comply with the safety guidelines?

5G technology will be used in a wide range of devices and will be the backbone for the Internet of Things (IoT). All these devices will be evaluated to ensure that they conform to the RF safety limits adopted by agencies around the world.

Is 5G safe for children?

Yes – The EMF safety limits cover the 5G frequency range and include substantial margins of safety to protect all people including children from all established hazards.

What about children wearing RF transmitting devices or wearables for security or entertainment?

The radio transmitters in such devices are generally transmitting with very low power. When tested they are required to comply with national or international exposure limits. When watching a video the device is mostly receiving information and only transmits information for brief periods.

Other types of devices such as personal trackers also transmit for short periods of time.

Will 5G devices automatically minimise transmitter power?

Yes – 5G devices will automatically minimise the transmit power to the lowest level in order to complete a satisfactory communication with the network. Such automatic power control has existed in previous generations of mobile technologies (2G, 3G and 4G) and helps to minimize interference, prolong battery life and also has the effect of limiting the EMF exposure of the user. The transmit power of the device is controlled by the network.

Does 5G mean higher power and higher exposure levels?

No – 5G networks are designed to be more efficient and will use less power than current networks for similar services.

With the introduction of new technologies, there may be a small increase in the overall level of radio signals due to the fact that new transmitters are active. In some countries deployment of 5G may occur as part of closure of earlier wireless networks. Based on the transition from previous wireless technologies we can expect that the overall exposure levels will remain relatively constant and a small fraction of the international exposure guidelines.

What types of base stations are used for 5G?

Base stations used for 5G will consist of various types of facilities including small cells, towers, masts and dedicated in-building and home systems.

Small cells will be a major feature of 5G networks particularly at the new mmWave frequencies where the connection range is very short.

To provide a continuous connection, small cells will be distributed in clusters depending on where users require connection and this will complement the macro network 5G base stations.

5G networks will work in conjunction with 4G networks. In many cases, existing 4G base stations will be used for additional 5G equipment.

Do 5G base stations automatically minimise transmitter power?

Yes – 5G networks are specifically designed to minimise transmitter power, even more than existing 4G networks. 5G networks use a new advanced radio and core architecture which is very efficient and minimises transmissions consistent with service requirements which results in optimised EMF levels. The network also controls the power

level of the device to the lowest level in order to complete a satisfactory communication with the network.

What will be the size of compliance zones around 5G network antenna sites?

The technical standards for the 5G networks and devices are still under development however it is expected that the size of the compliance zone for 5G antennas will be similar to that of other mobile technologies using similar transmitter powers.

Mobile network antennas are typically directional. Compliance zones extend in front of the antenna and a small distance above and below.

Mobile networks are designed to use only the power needed to provide quality services. Too much power would cause interference and affect all users. One of the goals of 5G is a substantial increase in network energy efficiency.

Where 5G is added to an existing site with other mobile technologies, the existing compliance zone may increase due to the addition of the 5G technology however this will depend on the site design and network configuration.

Is 5G similar to the Active Denial System used by the military?

No – Active Denial Systems developed by the military use very high powered mmWave directional signal, sometimes called a ‘heat ray’ in the 90 GHz band designed to heat the surface of targets such as the skin of a human, and through the heat, control or restrict access.

5G and other mmWave radio communications use different frequencies and a fraction of the power. The human exposure limits for mobile communications technology prevent heating occurring.

Additional information on ADS systems is available here.

http://jnlwp.defense.gov/About/Frequently-Asked-Questions/Active-Denial-System-FAQs/