5G is the fifth and latest technology standard for broadband cellular networks. It follows a series of previous generations that began with 1G in the 1980s. Approximately every decade has seen a new standard bringing new technical innovations and improvements.

1G enabled the use of voice calls, while 2G introduced text. 3G allowed users to browse the internet at speeds of 384 Kbps.  4G was rolled out in the 2010s with typical download speeds of 10-20 Mbps but a theoretical maximum of 1 Gigabit per second.

5G aims for a maximum download speed of 10 Gigabits, but in 2021 average speeds were being measured at around 100-400 Mbps. These higher speeds mean 5G can be a competitor to home broadband services, offering a much improved version of the Fixed Wireless Access (FWA) services available in 4G.

5G networks can have much lower latency, i.e. the time it takes to transmit a packet of data. 4G latency ranged between 60ms (milliseconds) and 98ms, but 5G aims for under 1ms. This enables use cases where near-instantaneous responses are required, such as gaming and the control of machines in factories.

5G also offers an improved ability to handle many devices at the same location, paving the way for the connection of increasing numbers of Internet of Things (IoT) devices.

5G deployments arguably started in 2018 in the USA but got properly underway in 2019 with many EU countries offering a limited service in cities. This developed throughout 2020 and by the end of the year, there had been commercial 5G launches in all EU countries with only four exceptions.

The EU’s first 5G initiative, the 2016 5G Action Plan, was designed to boost the roll-out of 5G. By 2021, most of those objectives had been met and improving coverage became one of the European Commission’s key targets.

5G deployment began in cities, and extending this nationwide is the next step. This is particularly challenging for 5G because it achieves higher speeds by using higher frequency bands, like 3.5 GHz and above, where signals do not travel as far as in the lower bands traditionally used for mobile. This requires more base stations and makes rural coverage more expensive. 5G services can be offered in the lower bands used for 4G, like 700 MHz, but in these frequencies 5G cannot offer the same speed boost.

5G is at an early stage in harnessing the full potential of services it can offer to vertical industries. Trials are underway and countries like Germany have had an enthusiastic take-up of local licences designed for verticals. But the level of commercial deployment is far behind that achieved in consumer services.

Like 4G, 5G was developed in the  3GPP standardisation body. Its work on 5G  began in 2015, with the first specification released in 2017. In June 2020, Release 16 was published, focussing on the verticals’ needs such as  Automotive, Industrial IoT and Operation in unlicensed bands.

Release 17, due in June 2020 will concentrate on three main use case families: enhanced mobile broadband (eMBB), ultra-reliable low latency communications (URLLC) and massive machine-type communications (mMTC). This will support expected growth in mobile-data traffic as well as customising NR for automotive, logistics, public safety, media and manufacturing use cases.

We summarise the new technologies used by 5G below.

Network virtualisation (NV)

Network virtualisation (NV) uncouples the network hardware and software. In NV a virtual network runs on top of the physical network, which results in a more dynamic system that can be more easily configured. NV also allows network functions to run on IT servers rather than dedicated hardware.

5G NV will allow hardware resources to be divided into functions. This is called network function virtualisation (NFV). NFV directly optimises network services.

Software-defined networking (SDN) separates the control plane and data plane of the network architecture. This establishes a new centralized view of the network.

Network slicing

Network slicing splits up the 5G network into slices. Each of these can be tailored for a specific purpose and act as its own independent network.

This allows the same hardware to serve different use cases with specific needs. It is also a support for the multiple air interfaces, which can include the LTE air interface as well as a newly developed air interface.

It is relatively well accepted within the industry that network slicing should really focus on the full integration of LTE-A with 5G but only bring limited interworking with 2G and 3G, which are native circuit- switched radio access technology, whose full support would be complicated and counter productive

Network Slicing has become a fundamental 5G technology element enabling a wide range of use cases and providing customised connectivity. It is thus possible to provide very low latencies in some network slices and very high bandwidth in other slices.

HetNets

5G aims to support Heterogeneous Networks are wireless networks comprised of different types of base stations and wireless technologies. Hetnets manage macro, small cells, Distributed Antenna Systems (DAS) and Wi-Fi hotspots if available.

Multiple Input Multiple Output (MIMO)

MIMO technology is key to improving spectrum efficiency. Massive MIMO uses a very large number of service antennas (hundreds or thousands) that are operated in a fully consistent and adaptive fashion.

Multiple User (MU-MIMO) form offers a dual advantage: a base station that can communicate simultaneously with multiple user equipment on the same frequencies and the ability to send multiple data streams.

Beamforming

Beamforming is about controlling and reducing interference. It requires MIMO antennae and is able to broadcast the same signal using multiple antennae. It uses signal reflection and diffusion to perform communications in non-line-of-sight (NLOS) situations.

The combination of massive MIMO and beamforming techniques creates the ability to pack more elements and concentrate the transmission’s path towards a receiver, and thus increase coverage with a single antenna at a time when antenna elements are becoming significantly smaller.

Use of mmwaves

Mmwave is a specific part of the radio frequency spectrum between 24 GHz and 100 GHz which has a very short wavelength. 5G takes advantage of these higher frequencies, particularly the 26 GHz band and the 28 GHz band for higher data rates above 1 Gbps. The 26 GHz band is primarily used in Europe and China, while the 28 GHz band is used in the USA, Japan and South Korea.

However, these higher bands do also come with limitations. They can only travel a limited amount and can be disrupted by weather or other physical limitations.

Dynamic Spectrum Sharing (DSS)

Dynamic Spectrum Sharing  enables 5G to be deployed simultaneously with 4G and co-exist in a single carrier.

This allows both 4G and 5G users to be accommodated for on the same spectrum with dynamic resource allocation. This can maximise operational efficiency and offer a smooth transition from 4G to 5G.

Open RAN

Open RAN is a developing technology that will allow operators to mix and match components from different suppliers in their towers and base stations.

This will allow for more innovation and options for the operator and could assist in the speed of 5G rollout.