Is this the future of communications?

Come read about cell-free networks and antenna arrays as big as a house, quantum communications, metamaterials and neumorphic computing.

The UK telecoms and media regulator Ofcom has today published a report that, in its words, “takes a look at some of the emerging technologies that could shape the way we live, communicate and entertain ourselves in the future.”

In an introductory video, Simon Saunders, Director Emerging and Online Technologies, Ofcom, says that it is essential for Ofcom to keep up with technological advances, so that it can help to deliver the benefits to the UK.

Saunders says that despite us reaching “what seems like the limits of communications technology” there are new technologies that could further transform communications experiences. He lists immersive sensory communications, robots and AI that could allow media to be created with richer content, and the development of quantum technologies and new materials that could make networks faster and more consistent.

New fibre technologies and clusters of satellites and aerial vehicles working together with ground networks, could deliver faster services everywhere in the world, Saunders said.

Ofcom produced a full 97 page report “on the technologies shaping communications for the future”.

Here’s a run through of one section on “Mobile and Wireless Technologies”, which runs to about 10 pages in the report itself.

The report starts by capturing “where we are now”. It notes that MIMO, now a 25 year old technology, is pretty widely deployed. Massive MIMO, 10 years on from its proposal, is now well understood, although theory still runs ahead of practical benefits so far. Carrier aggregation has also contributed to increased throughputs. Open and, to some extent, cloudified radio networks are beginning to emerge, so that “the boundaries between radio, network and IT infrastructure are dissolving”. Shared access and unlicensed spectrum schemes are also changing the useability and usage of radio spectrum. More “things” are being connected, and critical use cases enabled by URLLC. AI is enabling more energy efficient networks.

After that run through, the section titled “Where we are going next” starts by looking at technologies that may challenge fundamental assumptions about the limits of communications technology.

A section called going “Beyond Shannon’s limits” looks at intelligent reflecting surfaces (IRS) – a theoretical means of changing the “channel” itself so as to change propagation characteristics. Metamaterials “appear to waves that encounter them to be just like natural materials but with extraordinary characteristics like a refractive index of less than one (meaning that waves speed up in them) or even a negative refractive index (meaning that the wave reverses direction). The engineering possibilities this enables are remarkable, for example regions of space can be ‘cloaked’ in the sense that waves pass around them and any object in them without any disturbance that can be observed externally, albeit only in limited bands.”

The section also address “extremely large antenna arrays” – which it terms, “Another example of how changing fundamental assumptions could lead to disruptive innovations in wireless systems.”

These arrays go way beyond the 64T/R type arrays that we currently see, to envisage elements spread across the entire surface of a building, although it does point out that with such element separation exceeding the size of the wavelength, there’s a lot of other work required to make such an array practical.

Another potential Shannon buster is to change the carrier itself, by using Quantum Communications.

Whilst these are potential Shannon limit busters, the report also identifies advances in AI that could overcome the fundamental physical limits of Moore’s Law. These include neural networks, federated machine learning and neumorphic computing.

A third area of potential advance is the change the topology of a mobile network, moving beyond the current cell-centric layout  to cell-free networks that take advantage of those extremely large arrays mentioned a moment ago. The authors say, “Implementation would require very tight and accurate synchronisation between antenna locations and the transport of large amounts of data between sites, placing greater reliance on a dense fibre-based backhaul/fronthaul transport network.”

Then there’s the idea of generating coverage from the skies, using drones and planes in communication with ground systems. The paper also touches on new optical wireless communications, including LiFi – the use of visible light for short range communications

Finally, and one area that most will recognise from 6G discussions to date, is the idea of Terahertz communication and sensing.

Terahertz waves, being so close together, can be used to characterise even very small movements. The report says, “For positioning applications, THz can provide centimetre and sub-centimetre level accuracy using high-resolution maps of the environment. Thus, THz communication, sensing and positioning is regarded by some as one of the most promising technologies for future 6G systems.”

It’s an accessible report that sets out some future communications possibilities and gives insight into work that doesn’t often leave the academic environment or industry research labs. Well worth a read.