Japanese operators are lagging their counterparts in the U.S. and South Korea in deploying 5G, but when it comes to 6G, they are aiming to take the lead.
Japanese carriers are expected to roll out 5G this year in major metropolitan areas and expand to rural areas by 2022. DoCoMo and KDDI have said that they will have 90% of the country covered by 2025. Softbank, meanwhile, expects to have 64% of the country covered by its 5G network by 2025.
Perhaps this slightly slower pace is prompting the country to take a leadership position when it comes to 6G. In November the Japanese government said it would devote $2.03 billion to encourage private-sector research and development on 6G.
And in January DoCoMo released a white paper about 6G. In the paper, researchers predict that 6G will be introduced in 2030. At this point, DoCoMo says many of the 5G use cases—such as delivering enhanced mobile broadband and ultra-low latency communications for consumers and industries—will have occurred. But by 2030, DoCoMo says that there will be a need for more advanced wireless services that can do such high-brow things as solve social problems, provide communications between humans and things, and provide sophisticated cyber-physical fusion.
What the heck is cyber-physical fusion? According to DoCoMo, it’s the transmission and processing of large amounts of information between cyberspace and physical space with no delay. For humans, that means thoughts and actions are transmitted in real-time through wearable devices, or as we say in the Sci-Fi world, mind control.
If this sounds pretty far-fetched to you, you are not alone. I studied the white paper with a heavy level of cynicism. Having lived through the transition from analog cellular to 2G, 3G, 4G and now 5G, I’ve become pretty accustomed to hearing the hype about new networking technologies that never quite live up to the promises.
So has Lynnette Luna, principal analyst at GlobalData, who notes that many of the capabilities promoted with 4G networks, such as dynamic pricing and enhanced mobile broadband services, didn’t happen and are now being touted as 5G use cases. “A lot of these capabilities depend upon spectrum resources,” Luna says. And she predicts that some of the 5G use cases that were discussed early on such as autonomous cars, probably won’t happen, or at least won’t be widespread. “There will be pockets of areas where you have ultra-low latency with edge computing but that is expensive to put everywhere,” Luna says.
DoCoMo’s white paper outlines 6G as having peak data rates greater than 100 Gbps and latency rates lower than 1 millisecond all the time. It also discusses the possibility that operators will use new spectrum in the terahertz wave frequencies, that are higher on the spectrum chart than 95 GHz. Considering 5G is being deployed in the 28 GHz to 39 GHz millimeter wave spectrum, this seems pretty ambitious.
As far as coverage, DoCoMo talks about the 6G network being so pervasive that it will not just be on land but also in the sky, sea and space. To accomplish that, 6G will need to include more than just traditional cellular networks. DoCoMo says the new 6G network topology will likely be three-dimensional and will include geostationary satellites, low-earth orbit satellites and something called high altitude pseudo satellites (HAPS) that can be stationed at a fixed location at an altitude of 20 kilometers and form a wide coverage area. HAPS will be able to provide backhaul or portable cell coverage.
Cell sites and antennas will also be revamped in the 6G world. Hexagonal cell sites will be necessary to reduce interference and antennas may be made of different materials and combined with reflectors and sensors.
Of course, many of the technologies that are being used today to make 5G happen—such as millimeter wave spectrum and massive-input massive-output (MIMO) antennas seemed pretty ambitious when 5G was just a concept.
But one very critical item not addressed by DoCoMo’s white paper is cost. Creating a three-dimensional network that incorporates satellites, terahertz radio spectrum, and a massive amount of antennas sounds like it carries a pretty big price tag.