Get Ready for the Greatest Change in Our Digital World Since the Start of the Internet … Meet the…

Get Ready for the Greatest Change in Our Digital World Since the Start of the Internet … Meet the 5G Game-changer

And Things Are Going To Get A Whole Lot Smaller … and Goodbye (Finally) To Copper Cables

I did my PhD on the propagation of electromagnetic waves using Maxwell’s equations in the time domain. My computer had 16MB of memory and I had four processors to run the simulation in parallel. These days, for a few dollars an hour, I could get 100s of thousand of processors with almost unlimited amounts of memory. So it shows how we have progressed over the years.

One thing I learnt in my PhD was that an antenna was half the length of the wavelength (𝜆/2). And so I modelled patch antennas and which were around half a wavelength long. From Physics, we know that v=f𝜆, and where v is the speed of the wave, f is its frequency, and 𝜆 is the wavelength of the wave. The frequencies I looked at were around 2.4GHz, and so the wavelength is (assuming that the speed of light is 300 million metres per second — 3ｘ10⁸):

𝜆 = 3ｘ10⁸/f = 0.125 m

Thus, one wavelength is 12.5 cm, and half a wavelength is 6.25 cm. If you measure it, that will be the size of the dipole antenna on your wireless router, as we use 2.4GHz for Wi-fi transmissions.

I also learnt that the capacity for data on wi-fi varied directly with the frequency carrier, and so the higher the frequency of the carrier, the higher the data rate that we can carry. As an estimate it is around 1/10th of the carrier frequency. So for 2.4GHz, we get a data rate potential of 240Mbps. Our local Ethernet networks thus beat this with the potential to go up to 1Gbps. And so copper still wins in your current world.

But a whole new radio spectrum is opening up, and which will bring a great revolution to our industry, and get rid of copper cables forever. It is 5G — and forget the hype, as this scale-up is real — and will be the most radical step forward in the Internet since its creation. It will thus enable a new generation of devices to connect to the Internet, and create networks which are ultra fast, secure and which can truly connect devices around the world through wi-fi, as if they were connected to each other. Most importantly the ‘latency” — the delay it takes to transmit data from one place to another — will drop massively.

The spectrums which are opening up are:

We can see that we are going from 24.25GHz, right up to 86GHz. At this frequencies our wavelengths are 1.2 cm to 0.3cm. Our antennas will thus be between 0.6 cm and 0.15 cm long. As we move up 86GHz our capacity for data will move from just 240Mbps to 8.6Gbps. This is from a single wireless stream, and, if we use multiple paths, such as with MIMO antennas, we could multiple up this even more.

Our Cat-5 cables will just seem so slow compared with this. The lower frequencies (24.25–27.5GHz) will be used for macro scale networks, and which provide a wide coverage (in the way our existing 4G networks do), but local networks will scale from small to ultra-small, and support higher frequencies. The higher the frequency we go, the more reliant that we are on line-of-sight communications, thus the higher frequencies will require more localised connections (and where signals can bounce off objects).

We are currently building a 5G test bed will be up at our simulated hospital at our Sighthill Campus, and Adrian Smales is the main researcher on this project.