The wireless future beyond 5G is in the terahertz spectrum

14 Sep 2017

From left: Dr Alan Davy, Terapod project coordinator, with Sasitharan Balasubramaniam, acting research director, TSSG. Image: Patrick Browne

Imagine speeds 1,000 times faster than today’s optimum wireless speeds.

Tech experts and academics from all over Europe were in Ireland this week, collaborating on the future of wireless beyond 5G.

Waterford Institute of Technology’s TSSG group played host to industry partners Dell EMC as well as partners in the Terapod (terahertz-based ultra-high bandwidth access network) group, a €3m EU-backed consortium.

‘This is beyond 5G and it could even be 8G or 10G, and could serve demands that are 10 or 20 years down the road’

Terapod is devising a novel way of communicating wirelessly for the decades to come.

The future of wireless

Currently, the state of the art is in the 60GHz spectrum range, at millimetre wave.

However, the terahertz spectrum range is in the sub-millimetre range, or 300GHz, between high-frequency infrared (IR) and just below optical physical light.

A good analogy would be the split second it takes for the new Face ID sensors on the iPhone X smartphone to examine 33,000 IR dots that map your face and unlock the phone, even in poor light conditions.

“Very close but in terahertz, rather than depth sensing on the face, imagine doing that in high resolution,” explained Dr Alan Davy, leader of the Terapod team at TSSG.

“Terahertz can be used for industry applications like imaging. Take a picture and gather data below a number of layers – almost like x-ray, but non-polarising – and it doesn’t affect any of the atoms.

“This is beyond 5G and it could even be 8G or 10G, and could serve demands that are 10 or 20 years down the road. Terahertz is definitely not something that is near-term.”

Davy explained that Dell EMC is an industry partner on the project because it is interested in how terahertz could inform the future of modular data centres. He said that terahertz wireless links could remove the need for cabling in data centres, making them easier to run and more modular to build, and enabling compute power and storage to be beefed up, just like adding Lego.

One of the partners, the Technical University (TU) of Braunschweig, is working on putting standards in place for terahertz technology.

“The reason the data centre is a good early-adoption case is, the data industry is looking to invest in capabilities that boost performance.”

Davy said that the testbed for terahertz networks is already up and running at TSSG, with speeds of up to 100Gbps transmitted over a range of less than 10 metres.

But will this technology revolutionise cellular networks any time soon?

Probably not, as Davy pointed out that currently, there is a lot of molecular noise in the 300GHz range as wireless signals bounce off water and oxygen molecules. However, the one place it works particularly well is in orbit, and the technology could be a fascinating and fast new way of linking high-bandwidth satellites.

But right now and back on Earth, TSSG is the project coordinator of the EU-backed initiative, and the partnership with Dell EMC means TSSG can test the findings in its own, as well as the former’s extensive data centre networks.

“Dell EMC is very excited to be a part of Terapod, and we look forward to achieving significant technology advances to accelerate our R&D efforts in the data centre through this collaboration with Dr Alan Davy and the project team,” said Donagh Buckley, senior director at Dell EMC Research Europe.

“Innovation is the lifeblood of Dell EMC and our external research investment enables us to explore emergent technologies and engage with leading researchers.”

Beyond the network noise

A European Commission (EC) spokesperson said the EU and the EC support the Terapod ambition to exploit frequencies above 90GHz as a potential solution to the saturation of wireless spectrum access in Europe. “We welcome its objectives of assessing the feasibility of ultra-high bandwidth access networks and of exploring the elaboration of a technology roadmap for THz communication beyond 5G.”

The other partners in the project are the University of Glasgow (UG) and University College London (UCL), the National Physical Laboratory (NPL) and Bay Phonics in the UK. German partners include TU Braunschweig, Vivid Components and ACST. The sole Spanish partner is VLC Photonics and the team also includes Inesc Tec from Portugal.

UG said that Terapod seeks to replace the current ‘cable jungle’ with compact and very high throughput, in the tens of billions of units of information-per-second range (gigabit per second) and low-cost wireless interconnects benefiting the internet, freeing up room and reducing costs in presently cable-clogged data centres.

UCL’s Dr Cyril Renaud said: “We have worked in millimetre-wave and THz communication technologies for more than 10 years, and have participated in the development of the technology as one of the arguably leading contenders for wireless high-data-rate links.

“However, so far, no real test of THz system within an application setting have been done to fully assess performances, from devices to full network design.

“This is where I believe Terapod is hugely exciting and at the forefront of the research work in the field internationally, as it brings experts from each layer of a communication system and will aim at improving every element of that network, from devices to architecture.”

John Kennedy is a journalist who served as editor of Silicon Republic for 17 years