Radio technology for 5G - making it work. Guest blog written by Roger Green.

My first real job was tuning IF stages on VHF SSB radios for Pye Telecom in St Andrews Road, Cambridge (does anyone remember them?), using a hand-built diode probe and AVO 8. I was also privileged to witness the beginnings of cellular as Racal, the company I was at the time working for, demerged out of the fledging Vodafone.  Roll forward 30-ish years and here I am, a Bristol University first year PhD communications student, witnessing the birth of 5G…

So, what is 5G exactly? Is it going to allow me to stream ‘Game of Thrones’ in 1080p whilst waiting for the next tube train on the northern line? Well apparently, not…yet 

The Cambridge Wireless (CW) event that I recently attended, “Radio Technology for 5G - Making it work”, was full of the industry’s movers and shakers with each presentation being a clear and concise representation of not only the potential of 5G, but also its problems and possible pitfalls.

5G promises a massive increase in data throughput and reduced latency. This opens up a great deal more uses than just mobile telephony, such as vehicular communication (and control), virtual reality and many industrial applications. The latter may form high data, low latency control, such as factory robotics, or the internet of things (ie the use of a lower data rate for monitoring, such as utility meter reading or asset tracking).

However, there are still multiple hurdles to overcome. Much spectrum is still to be allocated, with the right balance between shared space and private space to be found. For really high-speed data, the mmWave needs to be used but this holds many engineering challenges as well as physical ones. Multiple antennae are a necessity at these frequencies, but there are obvious space issues when trying to incorporate multiple antenna arrays (providing diversity) into handsets. 5G is also designed to co-exist with 4G on the same bands, but an optimal 5G system would, if designed from scratch, not be in the cellular form. Yet despite the complexity of 5G, the standards body have pulled together specifications in a much shorter space of time than for 4G.

One of the key features of 5G is the use of beamforming which can be applied at any band but does require multiple antennae – the base station most likely having a larger number than the mobile device. Beamforming allows spatial diversity which overcomes the path loss at the mmWave frequencies.

5G in its early deployment is going to be installed in data hot spots in the UK’s larger cities – for example the West Midlands Combined Authority has recently won a grant to deliver a 5G testbed across Birmingham, Coventry and Wolverhampton – but also in rural areas where trials such as 5G Rural First and 5GRIT are ongoing. Furthermore, there is nothing to say that the recent increase in satellite coverage with low earth orbit satellites could not fill some of the geographical black spots, but this would require yet another band to be added to the mobile network. 

The Phase 1 trials will be completed in the next 6 months, and the Government expects the majority of the population to have 5G coverage by 2027. Initially, the lower frequency bands will be used. Antennae companies are getting ready, with chipsets appearing from vendors for both base station and mobiles.

So, what is 5G going to provide from a user’s perspective? Well it probably won’t be any more expensive to use as the cost of data usage continues to fall, but handset design is going to be a lot more complex – there are a large number of frequency bands currently on the table. In some areas, 5G may even replace WiFi as the de facto standard for indoor low mobility which means that 5G modems may be incorporated into laptops and tablets in the near distant future. 

What about when 5G is fully developed? Well, you will be able to stream HD video to your phone, your car may be able to self-drive and navigate (and hopefully not crash), and all your kids will undoubtably become ‘VR heads’ as it becomes impossible to separate them from their headsets! This may mean that I no longer require that large box of DVI, HDMI, ethernet and USB leads that I currently use to connect everything together! 

I have not really given justice to the depth and coverage of the presentations from CW’s radio technology for 5G – making it work event, but I am truly grateful to have been given the opportunity to glimpse what is going to become the future.  If you are interested in this exciting field, then there is a great deal of information on the internet. I would also suggest attending future CW events on this subject – first port of call is their website, www.cambridgewireless.co.uk.

For my part, I am just about to start my PhD on multiple antenna arrays and how to compensate for the way they interfere with each other when beamforming, hopefully this small piece of work may form a minor part of the realisation of 5G. Meanwhile, feel free to check out the poster I presented on the day on load pull compensation in Massive MIMO.

CW (Cambridge Wireless) strive to be known as a diverse and inclusive organisation which is why they are always happy to offer complimentary tickets to those working in academic institutions, students, not-for-profits and those who work in the field but may be unable to afford the ticket price.

To read our diversity and inclusion policy, click here.