The COVID-19 pandemic has illustrated to the world the importance of wireless communications. It has also helped accelerate demands on wireless data capacity and pressure for speeding up 5G development. However – like so many resources – there is not an infinite amount of wireless spectrum to support this growing demand. It is quickly becoming apparent that innovation in the technologies to support revolutionary 5G networks is desperately needed. It is in this context that the progress being seen in mmWave development is especially exciting.
Opening up a new range of frequencies
Traditionally, it was believed that frequency bands above 6 GHz were not suitable for mobile communications. This was due to the fact that these much higher frequencies were prone to propagation losses and signals could easily be blocked by geographic features, atmospheric conditions, buildings and even human bodies. These frequency bands (between 24 GHz and 100 GHz) are known as mmWave because of their short wavelengths which can be measured in millimetres. However, recent developments in antenna technology mean that we can now exploit these higher frequencies which before seemed out of reach. For example, Massive MIMO antennas have been foundational in opening up mmWave frequencies for use in mobile communications. The ability to utilise beamforming technology, giving pinpoint accuracy when targeting the spectrum, allow mmWave signals to get around some of the environmental hurdles that previously impaired its use in mobile communications.
The advantages of mmWave
At present, the most popular mmWave frequency bands in the industry are 26 GHz, 28 GHz and 39 GHz. These millimetre wave frequency bands are high, they have large propagation loss and abundant spectrum resources. Due to these reasons, mmWave devices are slightly different from 5G mid-band devices.
Firstly, mmWave devices have more accurate coverage capability. Because of the high frequency bands, antenna arrays can be much smaller so, for a given area, more antenna arrays can be deployed. This makes mmWave ideal for 5G applications in built up and urban locations.
Secondly, high-frequency equipment can support higher bandwidth and provide higher data rates. As the spectrum resources are rich, the high-frequency macro stations can support 40 times more bandwidth than a 4G LTE network and 8 times more than 5G 3.5 G NR networks. The single-user downlink rate can reach 4.2Gbps, which is far beyond what any other frequency bands could offer.
With the ultra-high bandwidth capability, mmWave can effectively support large-bandwidth uplink services such as live broadcasting of ultra-high-definition sporting events. In addition, due to the rich spectrum resources and clean frequency bands, mmWave networks are suitable for dedicated industrial networks, and can be used together with MEC and AI in the development of smart factories – a key feature of Industry 4.0.
The advantages of exploiting the additional range of frequencies that mmWave offers cannot be overlooked. This fact is especially stark when we see how the pandemic has changed the way people now live and work. The need for enhanced connectivity for everyone around the globe has become glaringly apparent, and the need for industry to modernise and embrace the new digital revolution is unavoidable. In this scenario, and with a finite amount of spectrum available, every step we take to increasing the bandwidth and range of our networks becomes more important.
The benefits identified with mmWave for use in public 5G and its ability to connect thousands more devices more efficiently is one such important step forward. Its applications in industry settings also highlight the fact that mmWave networks will be a fundamental aspect of our collective digital futures. 2021 will be a year of rebuilding and investing substantially in technological progress. Endeavours to improve, develop and implement mmWave networks will be at the top of our priority lists.
It is also important for infrastructure providers to demonstrate how mmWave technology benefits end users. There are already many examples that can be pointed to, which illustrate tangible use cases of mmWave. For example, the 5G mmWave network deployed at China’s National Cross-Country Skiing Centre, with a bandwidth of 800 MHz, is providing audiences with 8K multi-angle live sports broadcasts, as well as VR skiing experiences with up to 4.3 Gbps single-user peak data rate. This years’ MWC Shanghai highlighted many more examples of mmWave’s applications for ultra-HD video streaming and on-demand AR services.
By Mr Bai Gang, vice GM of RAN products at ZTE