Japan has a long-established reputation around the world for being at the forefront of telecommunications and its path to 5G is no different. With intense competition between four national operators and strict regulatory obligation, the country has somehow managed to reach nearly universal 5G coverage among its population—a tremendous engineering accomplishment that comes at remarkable cost. The activist approach of the government, with manmade initiatives such as Digital Garden City Nation Initiative to boot, has pushed the operators into investment-spending mode in order keep relevant and make these theoretically available to just about anyone.
But a deeper look at the experience of real users down on the ground reveals a digital split reality. National results aside, we have found a not-so-subtle discrepancy in the level of availability, speed and reliability on 5G coverage; thereby coining an entirely different league between hyper-dense city centers versus those in geographically challenging rural/mountainous prefectures as well.
The Urban-Rural Split Over 5G Coverage
The most daunting issue for Japan as it seeks to roll out 5G is that the country is one of a kind demographically. More than 92% of the population is urban, but operators are required by law to serve all 47 prefectures ― including those with difficult terrain and low population. This has created a bit of a strategic trade-off: operators opt to use mid-band 5G spectrum for speed and capacity where they are most needed in urban areas, saving the “good enough” stability of 4G network for serving the harder-to-reach regions.
This gap is clearly shown in performance data at the level of prefectures:
As an economic center, Osaka has very high 5G Availability scores, frequently above 35%. That’s a lot more time that users are spending on 5G.
Inland and mountainous prefectures like Yamanashi, by sharp contrast, are behind in the struggle, with 5G Availability falling below 10 per cent. Users in these areas are almost four times as unlikely to be connected to a 5G network than those in the cities.
On top of this gap of availability is a corresponding discrepancy in the velocity and constancy. Urban environments enjoy greater site density, which maintains the minimum speed even when extremely congested. On the flip side, though some low-density prefectures like Yamagata do tout very high median 5G speeds (because of less network congestion), their overall availability continues to be poor. For people living in the most sparsely populated regions, such promises remain largely theoretical; high-speed connection just never seems to materialize as a reality of day-to-day life, and this digital void further entrenches social and economic disparity.
It’s Not All About Cover, The Importance of Being Consistent
It’s only half the battle to achieve high median speeds because performance consistency is key—especially toward the lower end of the speed range—for robust services such as remote work, telemedicine and industrial IoT applications.
Consideration of 10th-percentile (bottom 10%-user experience) speeds exposes the vulnerability under certain areas of the network. Some of the operators are strong in metropolitan areas, and their quality greatly varies in rural prefectures. For instance, in certain inland areas, some operators’ minimum speeds can fall as far as 4 Mbps, but continue to remain high in coastal cities. This is in part due to the economic and technical challenge of deploying a densely packed network of high-frequency 5G base stations across a large mountainous country.
In practice, however, even a strict policy prescription by Japanese authorities has led to huge investments and a high overall national population coverage that belie the uneven state of local 5G availability, let alone user QoE. Bridging this gap will require ongoing, strategic investment — potentially including next-generation technologies like NNT — in order to fully realize the benefits of high-speed, low-latency 5G connectivity for all parts of the country, ultimately bridging the divide between digital infrastructure aspirations and real-world experience.
