I happen to live near New York City, where I went to college and later worked for a few years. While I don’t spend much time in the city these days, it’s fun to occasionally head in to see a show, go to a ballgame, or visit a museum.
However, should I need to use my phone on one of my infrequent forays into the Big Apple, I’m conditioned by now to expect coverage oddities and slower-than-usual download speeds. The phone often defaults to 4G/LTE service, which, frankly, is not much slower than, say, C-band 5G data rates.
At the high frequencies and short wavelengths of low-band 5G, the density of an urban environment poses challenges for network coverage and capacity. Even as R&D forges ahead for its eventual move to 6G, the cellular industry scratches its collective head as to how it might improve the user experience in the short term.
There are possible band-aids in the form of greater deployment of non-terrestrial networks (NTNs) and more melding of Wi-Fi with cellular technologies. But one technology that’s been talked up lately is reconfigurable intelligent surfaces, or RIS technology.
With reconfigurable intelligent surfaces, it’s possible to literally reshape the propagation environment of a given small area on the fly. This is accomplished through manipulation of large numbers of passive meta-surface reflection units.
By intelligently controlling signal reflections and collecting scattered waves into beamformed wholes, RIS technology, which is inherently passive and requires minimal power, can optimize signal paths, reduce interference, and enable network operators to use lower levels of transmitting power.
However, several technical challenges must be overcome before RIS technology can even begin to fulfill its promise. For one, optimizations for reconfigurable intelligent surfaces are an extremely complex affair. Channel estimations are particularly compute-intensive. The optimization algorithms must accurately handle phase adjustments; failure to do so will drag down the RIS’s ability to optimize signal strengths.
Companies like MathWorks are making significant progress in modeling of an RIS. In fact, we’ve got a Quick Poll on our site to gauge your interest in learning more about the subject.
To be sure, we’ve got a long way to go before 6G, or even 5G, get to the point where the technology is best positioned to serve wireless customers as well as it should. Reconfigurable intelligent surfaces may be one of the key elements to improve the situation. It’s a technology to watch in coming years.
