5G: how technology works and
why we need it
5G is one of the most talked about technologies at the end of the decade. In August 2019, it reached the peak of inflated expectations according to the Gartner Hype Cycle for Emerging Technologies . As in many similar cases, the information space is full of subjective assessments and fragmentary information. We will try to structure the understanding of 5G in terms of goals, technological parameters and user experience.
This is a new generation of mobile communications with a number of fundamental advantages over 4G:
- Higher data transfer rate;
- Low signal latency;
- The ability to connect more devices;
- High energy efficiency;
- Dramatically increased throughput;
- High user mobility.
Another important difference of 5G deserves attention – large-scale virtualization. New technology goes beyond hardware solutions alone. Many functions in it are implemented not at the level of physical infrastructure, but in software.
The key aspect of the technology, along with the parameters of the network capacity, is the product approach. Frequency bands, design features of stations and software components will be adapted to the needs of various categories of consumers – from users of gadgets to industrial enterprises and urban infrastructure.
5G broadens the context, offering a new understanding of technology: an innovative platform on the basis of which many industries will immediately receive additional impetus for development. This means the emergence of completely new services, business models, types of interactions between devices, production chains and infrastructure.
How the 5G technology appeared
2G – ~ 1990. The first generation of digital mobile technologies: CDMA, GSM, TDMA. SMS as a killer feature.
3G – ~ 2000. Mobile broadband, several megabits per second: EVDO, HSPA, UMTS;
4G – ~ 2010. Massively available mobile Internet up to gigabit speeds: LTE, WiMAX.In preparation for the deployment of fifth generation networks, we are closest to a single global standard. It is being developed by a number of international organizations, including:
|Peak download speed||1 Gbps||20 Gbps|
|Download speed for users||10 Mbps||100 Mbps|
|Delay||10 ms||4 ms (1 ms for URLLC)|
|Maximum travel speed without signal loss||350 km / h||500 km / h|
|Connection density||100 thousand devices / sq. Km||1 million devices / sq. Km|
|Traffic per unit area||0.1 Mbps / sq.m||10 Mbps / sq.m|
ITU-R is the organizer of the World Radiocommunication Conference (WRC or WRC). Every three to four years, the conference discusses key issues in the development of global radio communications and makes strategic decisions.
In 2015, within the framework of WRC-15, a decision was agreed on the allocation of the 3.4-3.6 GHz frequency range for mobile broadband (MBB) – these frequencies will become the basis of 5G for a wide range of users, at least in Europe and the USA. From October 28 to November 22, 2019, WRC-19 is planned, on the agenda of which, in particular, the allocation of bands in the range above 6 GHz.
In turn, 3GPP took over the development of the next generation Radio Access Technology – 5G New Radio or 5G NR. The consortium is working on standards and specifications that will shape the future of technology and the next generation of mobile communications in general. The most relevant of these: the “Release 15” compilation , released in June 2018, containing the initial requirements for 5G, as well as “Release 16” and “Release 17”, which are under development.
Frequency spectrum for 5G
If click bait headlines and enthusiastic posts on social media have convinced you that 5G is about ubiquitous coverage, gigabit speeds, and a frequency range somewhere in the 3-4 GHz region, then you have been misled. The situation is in many ways more prosaic and complex.
First, the transition to the higher frequency range is not directly related to the increase in speed. Second, the spectrum is much broader than the notorious 3.4-3.8 GHz range. 5G will use even such “out of fashion” frequencies as 700 MHz, as well as climb higher – up to 70 GHz.
Finally, at first, don’t expect staggeringly high speeds, especially for casual users. Of course, this is a real prospect, but before the infrastructure in the range of millimeter waves (mmWave) is deployed – the shortest, rapidly decaying, but providing speeds of several gigabits per second – the existing capacities will provide a not so significant increase in parameters.
The main reason for the transition to new bands is the lack of frequencies in the spectrum below 6 GHz. A new generation of mobile communications is being developed to provide operators with free frequencies, and at the same time wider bands within which more data can be transferred.
Frequency Range 1
Frequency Range 2
FR1 is not homogeneous in different regions of the world. So, in Europe and the USA, it is planned to use the 3.4-3.8 GHz range, and the most serious technology developers are guided by it. On the other hand, the East – Japan and China – are planning to use 4.4-4.99 GHz. Due to the lack of frequencies in the “western” spectrum, Russia plans to use the same range as its Asian neighbors.
Discussions are underway on this score: there are fears that the shortage of compatible equipment will increase the costs of operators and affect the quality of the work of domestic networks. At the same time, the compromise is being considered seriously, and perhaps the necessary frequencies will be allocated.
Frequency refarming is not unique to 5G, but it is also remarkable. The fact is that each subsequent generation of mobile communication differs from the previous ones not only by changing the range, but also by new coding technologies. At the same time, it remains possible to work on the basis of the previous generation infrastructure. That is, the stations previously used for LTE or, for example, for GSM, will continue to operate at the same frequencies, but now they will transmit data based on 5G technologies.
Refarming will save on infrastructure by providing optimal coverage for next generation networks. The initial stage of their launch on the existing equipment serving 4G networks is the NSA (Non-standalone) phase. Later, as we prepare the necessary infrastructure, we will be able to use SA (Standalone) 5G networks that support the full range of next-generation benefits.
The width of the line in 5G
Who is it for
eMBB – Enhanced Mobile Broadband / Enhanced Mobile Broadband
URLLC – Ultra Reliable and Low Latency Communications / Ultra reliable communications with low latency
mMTC – massive Machine Type Communication
A specific frequency spectrum and infrastructure is suitable for each of the layers:
- Radio waves in the low frequency range, up to 1 GHz, due to their penetrating ability, work well in closed rooms. They will ensure the operation of IoT systems, smart houses, M2M. Also, the 700 MHz frequency can use to provide communication for remote settlements.
- The middle spectrum or mid-band frequencies (1-6 GHz) combines the optimal capacity and coverage for the initial implementation of eMBB, and then URLLC and mMTC.
- Millimeter waves (> 24 GHz) bring 5G to its full potential. The priority area of application is highly load traffic zones (hot spots), massive user congestion.
Release 16, developed by 3GPP, will add new scenarios to this list, including:
- V2X (Vehicle-to-Everything) – low latency data transfer between moving unmanned vehicles and cloud data centers for remote management and maintenance.
- Satellite access – satellite access.
How 5G networks work
Often, next-generation networks will use existing infrastructure inherited from 4G and earlier generations. With more flexible coding and extended data channels, 5G NR will be 25-50% faster than LTE.
At the same time, we are expecting a large-scale implementation of both physical infrastructure and software solutions that will allow us to squeeze the most out of 5G.
To deploy standalone networks, new types of stations and transmission devices will install. Since we are talking about shorter wavelengths, which are less resistant to interference and obstructions from the environment, the coverage radius of each base station will be reduced. In this regard, a denser infrastructure will require, consisting of the so-called Small cells – small cells.
As a rule, stations with a capacity of 20-40 watts are use for mobile communication. They will replace by more economical, low-power stations with power ranging from 2 to 10 watts – they will provide massive high-frequency coverage and gigabit speeds.
Small cells fit better into the urban environment; they can installe on lighting poles, walls of buildings, public transport stops, and can made in the form of a simple object – an advertising lightbox or trash can.
By themselves, millimeter-wave antennas produce a rapidly decaying signal that has a limited directivity – only 4 degrees. But, reflecting off similar antennas along its path, the signal can remain strong and change direction, reaching the user.
Beamforming / Massive MIMO
In radio communication, there is the concept of Beamforming – beamforming. This is the process of directing and concentrating a signal with certain parameters in a certain direction. Within 5G, one of the practical solutions for this will be Massive MIMO (Multiple-In Multiple-Out) technology. It will help to avoid excessive microcell installation all over the place.
Massive MIMO refers to stations consisting of a large array of antennas that will be able to direct the signal more targeted and serve multiple users simultaneously, avoiding interference and loss of signal quality.
One of the key breakthroughs in next-generation networks is virtualization . With concepts such as SDN (Software Defined Networks) and NFV (Network Function Virtualization), entire classes of functions will be implemented in software rather than physical hardware.
An equally important role is played by the cloud architecture – C-RAN (Cloud / Centralized RAN). Cloud platforms will take over the functions that were previously performed by base station equipment, which will greatly optimize the infrastructure and affect the costs of operators.
The cloud platform requires less energy for maintenance and cooling than base stations. C-RAN knows the location of all users and can optimally allocate limited network resources between them.
Japanese operator NTT DOCOMO uses cloud infrastructure to cut power consumption of stations by more than 75% .
Technology implementation risks
Like any new technology, 5G carries risks. Whether they are justified or not is difficult to say – in most cases we are dealing with a research stage.
The main threats can consider:
what 5G Damage to health
- According to Gartner , revenues from 5G wireless networks will grow 89% in 2020 from 2019 to $ 4.2 billion.
- In Russia, operators’ investments in the development of 5G networks for the period 2020-2027 are estimate at 550-610 billion rubles, and with the joint use of base stations – at 400-445 billion.
- Mobile operators around the world are announcing 5G test launches . Devices on which the tests were successful: LG V50, OnePlus 7 Pro 5G, Samsung Galaxy S10 5G, Moto Z2 Force / Z3 / Z4.
- In Russia, VimpelCom report that the radio part of the network in Moscow was 95% ready. Tele2 is installing 50 thousand 5G-ready base stations.