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5G is ready for the 2020s, and 6G is expected to define the 2030s, although there’s no rigid cadence to engineering innovations, new things are discovered intentionally and accidentally all the time cellular wireless technology has moved toward a generation-per-decade model, such that 4G devices dominated the 2010s.
The key change underlying these generational shifts is an expansion of usable wireless spectrum. Miniaturized radios inside wireless devices can now broadcast on a larger number of frequencies than before, use multiple frequencies simultaneously, and fill wider channels with increasingly massive amounts of data.
The 4G-5G network difference has been previously explained as akin to widening an existing highway and adding new high-speed, extra-wide lanes. For wireless engineers, the challenge has been finding the space to build these highways. Throughout the 4G and 5G eras, governments have (slowly and with plenty of drama) reallocated military or otherwise reserved radio frequencies for consumer and industrial use. As 6G looms, engineers and governments are already planning to make use of “terahertz” spectrum, a block of radio frequencies so high that all-new testing equipment, chips, antennas, and other innovations are needed for commercialization.
While most people think of wireless technologies as almost magical, the underlying science is radio engineering, which has been around for over a century but advanced significantly in the past two decades. Just as home and car radios received audio broadcasts from giant outdoor towers, similar radios later shrink to fit inside computers, phones, watches, and earbuds, receiving data from smaller wireless base stations (and other devices).
Today, terahertz technology can be used to make cameras that “see” beyond the limitations of human eyes. Like millimeter waves, submillimeter waves can be used to detect weapons concealed inside clothing; they can also pass through soft tissue to image bones and peer through one layer of paint to see what’s underneath it. Companies such as Terasense, Ino and i2s have already developed terahertz cameras that can be used to see through materials or detect tiny manufacturing defects, though the price tags can be shocking because the lens is sold separately.
It’s fair to say that terahertz tech isn’t coming to smartphones anytime soon. Assuming international standards organization 3GPP does indeed coalesce on terahertz frequencies as foundational for 6G networks, the technology isn’t expected to be ready for commercialization in pocket devices until around 2030. Samsung thinks early devices could happen as early as 2028 with mass commercialization following two or more years later. A similar 10-year timeline proved to be enough to transform millimeter waves from an engineers’ dream into a viable cellular technology, so don’t bet against it happening over the next decade.
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