what is 5G technology

5G is generally seen as the fifth generation cellular network technology that provides broadband access. The 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. 3GPP will submit their 5G NR to the ITU. It follows 1G, 2G, 3G and 4G and their respective associated technologies (such as NMT, 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 Corporation30,000 and LG U Plus 18,000; of which 85% are in six major cities.^[2] They are using 3.5 GHz (sub-6) spectrum in non-standalone (NSA) mode and tested speeds were from 193 to 430 Mbit/s down. 260,000 signed up in the first month and the goal is 10% of phones on 5G by the end of 2019.

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 in NSA mode. In May, download speeds in Chicago were from 80 to 900 Mbit/s. Upload speeds were from 12 to 57 Mbit/s. The round-trip delay time was 25 milliseconds. It was reported in May 2019 that Verizon's 5G service would regularly hit 1 Gbit/s in some locations.

Six companies sell 5G radio hardware and 5G systems for carriers: Huawei, ZTE, Nokia, Samsung, Datang Telecom, and Ericsson.

5G cellular systems overview

As the different generations of cellular telecommunications have evolved, each one has brought its own improvements. The same will be true of 5G technology.

·         First generation, 1G:   These phones were analogue and were the first mobile or cellular phones to be used. Although revolutionary in their time they offered very low levels of spectrum efficiency and security.

·         Second generation, 2G:   These were based around digital technology and offered much better spectrum efficiency, security and new features such as text messages and low data rate communications.

·         Third generation, 3G:   The aim of this technology was to provide high speed data. The original technology was enhanced to allow data up to 14 Mbps and more.

·         Fourth generation, 4G:   This was an all-IP based technology capable of providing data rates up to 1 Gbps.

Any new 5th generation, 5G cellular technology needs to provide significant gains over previous systems to provide an adequate business case for mobile operators to invest in any new system.

Facilities that might be seen with 5G technology include far better levels of connectivity and coverage. The term World Wide Wireless Web, or WWWW is being coined for this.

For 5G technology to be able to achieve this, new methods of connecting will be required as one of the main drawbacks with previous generations is lack of coverage, dropped calls and low performance at cell edges. 5G technology will need to address this.

5G requirements

As work moves forwards in the standards bodies the over-riding specifications for the mobile communications system have been defined by the ITU as part of IMT2020.

The currently agreed standards for 5G are summarised below:

SUGGESTED 5G WIRELESS PERFORMANCE
PARAMETER	SUGGESTED PERFORMANCE
Peak data rate	At least 20Gbps downlink and 10Gbps uplink per mobile base station. This represents a 20 fold increase on the downlink over LTE.
5G connection density	At least 1 million connected devices per square kilometre (to enable IoT support).
5G mobility	0km/h to "500km/h high speed vehicular" access.
5G energy efficiency	The 5G spec calls for radio interfaces that are energy efficient when under load, but also drop into a low energy mode quickly when not in use.
5G spectral efficiency	30bits/Hz downlink and 15 bits/Hz uplink. This assumes 8x4 MIMO (8 spatial layers down, 4 spatial layers up).
5G real-world data rate	The spec "only" calls for a per-user download speed of 100Mbps and upload speed of 50Mbps.
5G latency	Under ideal circumstances, 5G networks should offer users a maximum latency of just 4ms (compared to 20ms for LTE).

5G communications system

The 5G mobile cellular communications system will be a major shift in the way mobile communications networks operate. To achieve this a totally new radio access network and a new core network are required to provide the performance required.

·         5G New Radio, 5G NR:   5G new radio is the new name for the 5G radio access network. It consists of the different elements needed for the new radio access network. Using a far more flexible technology the system is able to respond to the different and changing needs of mobile users whether they be a small IoT node, or a high data user, stationary or mobile.

·         5G NextGen Core Network:   Although initial deployments of 5G will utilise the core network of LTE or possibly even 3G networks, the ultimate aim is to have a new network that is able to handle the much higher data volumes whilst also being able to provide a much lower level of latency.

5G technologies

There are many new 5G technologies and techniques that are being discussed and being developed for inclusion in the 5G standards.

These new technologies and techniques will enable 5G to provide a more flexible and dynamic service.

The technologies being developed for 5G include:

·         Millimetre-Wave communications:   Using frequencies much higher in the frequency spectrum opens up more spectrum and also provides the possibility of having much wide channel bandwidth - possibly 1 - 2 GHz. However this poses new challenges for handset development where maximum frequencies of around 2 GHz and bandwidths of 10 - 20 MHz are currently in use. For 5G, frequencies of above 50GHz are being considered and this will present some real challenges in terms of the circuit design, the technology, and also the way the system is used as these frequencies do not travel as far and are absorbed almost completely by obstacles. Different countries are allocating different spectrum for 5G.

·         Waveforms :   One key area of interest is that of the new waveforms that may be seen. OFDM has been used very successfully in 4G LTE as well as a number of other high data rate systems, but it does have some limitations in some circumstances. Other waveform formats that are being discussed include: GFDM, Generalised Frequency Division Multiplexing, as well as FBMC, Filter Bank Multi-Carrier, UFMC, Universal Filtered MultiCarrier. There is no perfect waveform, and it is possible that OFDM in the form of OFDMA is used as this provides excellent overall performance without being too heavy on the level of processing required.

·         Multiple Access:   Again a variety of new access schemes are being investigated for 5G technology. Techniques including OFDMA, SCMA, NOMA, PDMA, MUSA and IDMA have all been mentioned. As mentioned above it appears that the most likely format could be OFDMA

·         Massive MIMO with beamsteering:   Although MIMO is being used in many applications from LTE to Wi-Fi, etc, the numbers of antennas is fairly limited. Using microwave frequencies opens up the possibility of using many tens of antennas on a single equipment becomes a real possibility because of the antenna sizes and spacings in terms of a wavelength. This would enable beams to be steered to provide enhanced performance.

·         Dense networks:   Reducing the size of cells provides a much more overall effective use of the available spectrum. Techniques to ensure that small cells in the macro-network and deployed as femtocells can operate satisfactorily are required. There is a significant challenge in adding huge numbers of additional cells to a network, and techniques are being developed to enable this.

These are a few of the main techniques being developed and discuss for use within 5G.

5G timeline & dates

5G is developoing rapidly and it needs to meet some demanding timelines. Some trial deployments have occurred and some of the first real deploymets are anticipayed in 2020.

Many countries are rushing to deply 5G as effective communications enable economimc growth and are seen as an essential element of modern day life and industry.