The 5G experience in Japan’s transport hubs: Yamanote line and international airports

In this latest Opensignal analysis on Japan, we have analyzed the 5G mobile experience in busy high-traffic areas of Japan —  across its international airports and on Tokyo’s Yamanote line, which connects some of the busiest train stations in the world. Our users on the Yamanote line and in these major airports were able to connect to 5G services for a higher amount of time than Tokyo or Yokohama city averages. However, differences in 5G Download Speeds were not as significant when we compared these high-traffic areas with city or Japan-wide averages.

Our 5G users on the Yamanote line connected to 5G services for 17.2% of the time — which was 2.3-2.6 times higher than across the whole of either Tokyo and Yokohama. This greater 5G Availability is partly because Japanese operators have deployed 5G infrastructure targeting users of the Yamanote line.

However, while the 5G Availability score was statistically higher for the Yamanote line than for two major Japanese cities, we saw a different story for Download Speed Experience and 5G Download Speed. Our users on the Yamanote line enjoyed an average overall download speed of 47.9 Mbps. This result was similar to the speed our users in Tokyo city experienced and was statistically the same as the score in Yokohama city. Similarly, for 5G Download Speed, we observed no statistically significant difference between our users on the Yamanote line and either the Tokyo or Yokohama average. 

Looking at the mobile network experience at the Yamanote line’s biggest stations, we observed differences in overall Download Speed Experience, ranging from 45.2 Mbps at Shibuya station to 56.6 Mbps at Akihabara station. This means our users at Akihabara station experienced 25.2% faster average download speeds than those in Shibuya. Looking at the average 5G Download Speed, Tokyo station saw 38.7% faster speeds than Ikebukuro. Our 5G users at Akihabara station connected to 5G services for nearly a quarter of the time.

The Yamanote line crosses through some of the busiest wards in Tokyo city, such as Roppongi, Shibuya or Shinjuku — which are major commercial and financial centers, also known for their nightlife. Looking at the differences in mobile experience at different times of the day in these three areas, we observed generally faster average 4G and 5G download speeds in the mornings, between 6 am and 12 pm. Compared to the mornings, our users saw drops in the afternoons, of 14.4% for 4G and 39% for 5G. 

We also looked at the average mobile network experience of our smartphone users when they connected to mobile services at five Japanese international airports — Chubu, Haneda, Kansai, Narita and Osaka. The overall average download speed of our users clocked in at 49.8 Mbps — 7.9% faster than Japan’s average. However, our users saw no statistically significant difference between the 5G mobile experience at Japanese international airports and the national average. They connected to the 5G services for 8.6% of the time, almost twice as often as the national average.

However, our users remained without any cellular signal at the biggest Japanese airports for 4.1% of the time — about eight times as high at these airports as the national average. This is likely due to the challenges of providing mobile infrastructure at airports such as secluded or distant spots, along with in-building walls that are hard for mobile signals to penetrate, and regulatory limits. Previously, we observed a similar issue at the busiest airports in the U.S. 

5G experience in high traffic areas should improve with eased power levels regulations

In our analysis, we observed that, while 5G Download Speed Experience in high traffic areas such as the Yamanote line was statistically similar to Tokyo or Yokohama city averages, 5G Availability was significantly higher. We have also noticed a drop in average 5G download speeds throughout the day in the high-traffic areas of Tokyo.

Today, the Japanese 5G experience is adversely influenced by strict power emission guidelines designed to avoid interference with other services, such as fixed satellite services or altimeters near airports. However, these are likely to be relaxed in 2023, including the Tokyo metropolitan area. With less strict power regulations, mobile users in Japan’s high-traffic areas should benefit from an improved 5G experience as the 5G signal will reach further from each base station and provide users with a better indoor 5G experience.