In a fascinating development, researchers in Japan are deploying and deploying a way of making 5G mobile (mobile broadband) infrastructure more discreet by creating transparent glass antennas that make it possible for windows to serve as base stations.
Modern 5G and future 6G networks only tend to deliver their best multi-Gigabit broadband speeds when they’re able to harness lots of higher frequency mobile spectrum. However, due to the limitations of signal propagation over distance from such low power communications, you need a dense and complex network of cell sites to fully utilise this.
The problem is that building a dense network of cell sites is expensive, as well as being one that tends to be increasingly hard to disguise and thus only really works at its best in the busiest parts of large cities and towns. But one possible way around that could be to turn ordinary windows into antennas.
The idea has actually been around for a few years now (here), albeit initially more focused on the automotive sector (here). However, the Tokyo-based communications company JTower recently deployed a glass antenna on part of a building in the Shinjuku district, which was developed by glassmaker AGC and mobile operator NTT Docomo (credits to ISPreview readers for spotting the IEEE Spectrum story). More deployments are planned to follow.
At present this only seems designed to work in the sub-6GHz bands (i.e. 617MHz to 5000MHz) and we don’t know much about its actual performance, but it seems unlikely to be able to beat a modern metal antenna. On the other hand, it could make up for that by being able to harness the mass of windows that exist pretty much everywhere, although only time will tell how practical this really is to deploy at scale.
Speaking of deploying at scale, it probably doesn’t help that there will be a distinct lack of suppliers for such kit, given that a technology like this is likely to be restricted due to control over related patents. Suffice to say that we probably won’t be seeing this happening much in the UK anytime soon, but’s it’s an interesting solution that could one day help to make mobile networks more discreet.