Known for connecting some of the world’s busiest train stations, the Yamanote Line in Tokyo carries up to five million passengers daily. To help understand the mobile experience on the go, Opensignal analyzed the overall and 5G experience of our users using this popular line. The study includes data collected both around the rail tracks, and the main stations — Tokyo, Shinagawa, Shibuya, Shinjuku, Ikebukuro, Ueno, and Akihabara — to measure commuters’ experience when they are on trains or in stations.
Opensignal has previously looked at the aggregated experience around the Yamanote line and other high-traffic transport hubs — but this time, we are looking at how the mobile experience differs between the four national Japanese operators. SoftBank comes first outright for Consistent Quality, 5G Availability, and 5G Games Experience. Meanwhile, au leads for Download Speed Experience and 5G Voice Experience, while Rakuten Mobile takes the top spot for Upload Speed Experience.
Au’s Download Speed Experience is around 20% faster than statistically tied SoftBank and NTT docomo while Rakuten Mobile significantly lags behind its competitors. However, Rakuten Mobile leads for Upload Speed experience, with a result nearly 60% faster than SoftBank’s and almost twice as high as au’s.
Looking just at 5G performance, we see less differentiation among operators. NTT docomo and au share the top spot for 5G Download Speed while Rakuten and Softbank are tied for 5G Upload Speed leadership. Both au and SoftBank’s overall and 5G speeds are higher around the Yamanote line than the Tokyo average in the same data collection period — and also much higher than operators’ country scores as reported in the latest Japan Mobile Network Experience report published in October 2023.
SoftBank comes outright first for 5G Games Experience, while au leads for 5G Voice App Experience — which measures the experience on OTT apps like LINE used for both messaging and voice calls. SoftBank and au rate as Excellent (85 or above) in 5G Games Experience. This means nearly all users experienced network performance that made them feel like they had control over the game and received immediate feedback on their actions when connected to 5G. Both au and SoftBank share the first place for all three overall experiential measures. 
Around the Yamanote line, our users on SoftBank’s network enjoy the most consistent quality of services out of all four national Japanese operators. The operator has the highest score of 84.5%, beating statistically tied au and NTT docomo by around 5.2 percentage points. These results reflect the proportion of tests that pass the requirements of Consistent Quality, along with the proportion of completed tests to all tests conducted. Compared to operators’ average Consistent Quality scores around Tokyo, our users experience slightly less consistent quality of services around the Yamanote line, likely due to the network congestion in this high-traffic area.
On top of Consistent Quality, SoftBank also shines for 5G Availability — our 5G users spend 28.3% of their time connected to 5G services on this network in the Yamanote line area. This is a fifth of the time more than in the case of second-placed au. Noteworthily, operators’ 5G Availability scores are significantly higher around the Yamanote line, compared to Tokyo’s average for each operator — or even more compared to the national scores from Opensignal’s October 2023 report. Our 5G users on au, Rakuten Mobile, and SoftBank networks spend 1.7 times more time connected to the 5G signal around the Yamanote line compared to the rest of Tokyo, while in the case of NTT docomo, time spent on 5G is even 2.1 times higher than the operator’s Tokyo average. However, there are no statistically significant differences between all four operators when it comes to their Availability scores. Availability measures the proportion of time all Opensignal users on an operator’s network have either a 3G, 4G, or 5G connection.
Japanese operators have been deploying 5G infrastructure around the Yamanote line, to provide fast and resilient networks for millions of commuters. In addition, the rail company JR-East has been investing in the 5G infrastructure-sharing business by deploying its own 5G equipment, to receive compensation from mobile operators who would use its antennas. Tokyo Metro has announced plans to provide high-speed coverage in the subway system, which also includes several stations intersecting the Yamanote line. Train stations around this line are one of the busiest in the world — and millions of travelers rely on fast and uninterrupted mobile services during their daily commutes.
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