Last year, Opensignal analyzed the mobile network experience of our users around the Yamanote line — one of the busiest metro lines in the world. We are revisiting this analysis 12 months later, to see how scores changed. Our data includes both rail tracks around the city but also the Yamanote line’s main stations — Tokyo, Shinagawa, Shibuya, Shinjuku, Ikebukuro, Ueno, and Akihabara.
Key findings
- Around the Yamanote line, SoftBank scores the highest for Consistent Quality — 86.2%.
- SoftBank also leads for 5G Availability around the Yamanote line area. Our 5G SoftBank users spend 40.3% of their time connected to 5G services — a third of the time more than on the runner-up au.
- SoftBank comes first for four out of five overall metrics around the Yamanote line area — outright for Voice App Experience and jointly for three metrics with au — Download Speed Experience, Video Experience and Games Experience.
- Rakuten Mobile leads for Upload Speed Experience.
- Au has the highest scores across all five analyzed 5G metrics, either outright or jointly. It comes outright first for 5G Games Experience and 5G Voice App Experience.
Around the Yamanote line, SoftBank scores the highest for Consistent Quality — 86.2%. Consistent Quality measures if the network is sufficient to support common mobile application requirements at a level that is ‘good enough’ for users to maintain (or complete) various typical tasks on their devices. SoftBank is the only operator whose Consistent Quality score around the Yamanote line is statistically similar to its Consistent Quality score around the whole area of Tokyo. Meanwhile, our users on other operators observe lower Consistent Quality scores around the Yamanote line compared to the city average. This is likely due to the network congestion, coming from millions of commuters using this transportation line daily.
SoftBank also leads for 5G Availability around the Yamanote line area. Our 5G SoftBank users spend 40.3% of their time connected to 5G services — a third of the time more than on the runner-up au. Generally, 5G users spend more time connected to 5G services around the Yamanote line, compared to the rest of the city. NTT docomo sees the highest relative difference, more than twice as high. SoftBank’s 5G Availability score around the Yamanote line is two-thirds higher than its Tokyo average, while au’s — 45% higher. All Japanese operators’ 5G Availability scores have substantially increased around the Yamanote line compared to our 2024 study.
Opensignal’s Reliability Experience measures the ability of Opensignal users to connect to and successfully complete (basic) tasks on communication service providers’ (CSP) networks. SoftBank and au are in a statistical tie for the highest score around the Yamanote line. For Availability, all Japanese operators have very high scores of signal availability — our users on au, NTT docomo and SoftBank spend 99.6-99.7% of their time connected to 3G, 4G or 5G networks.
SoftBank comes first for four out of five overall metrics around the Yamanote line area — outright for Voice App Experience and jointly for three metrics with au — Download Speed Experience, Video Experience and Games Experience. Rakuten Mobile leads for Upload Speed Experience — our users on this network enjoy 15% faster average overall upload speeds than their SoftBank peers.
SoftBank observes the biggest relative uplift in its Download Speed Experience score around the Yamanote line’s area compared to the rest of Tokyo — of 23%. In terms of experiential metrics — generally our users don’t observe substantial differences between the Yamanote line and the rest of Tokyo for Video Experience or Voice App Experience. However, operators’ scores for Games Experience are lower around the Yamanote line than their city averages — except for SoftBank, which sees a slightly higher score than its city average.
Looking just at 5G performance around the Yamanote line — au has the highest scores across all five analyzed 5G metrics, either outright or jointly. The operator comes outright first for 5G Games Experience and 5G Voice App Experience — which measures the experience on OTT apps like LINE used for both messaging and voice calls.
Both au and SoftBank place in the Excellent (85 or above) category for 5G Games Experience. This means nearly all users experience network performance that makes them feel like they have control over the game and receive immediate feedback on their actions when connected. For 5G Video Experience, regardless of their choice of a mobile operator, our Japanese users around the Yamanote line enjoy a Very Good (68-78) quality of 5G on-demand video services. This means that our users are, on average, able to stream video at 1080p or better with satisfactory loading times and little stalling when connected to 5G.
Both Tokyo Metro and Japanese operators have been deploying 5G infrastructure around the Yamanote line, to provide fast and resilient networks for millions of commuters. 5G connectivity enhances the line’s train control and passenger services, improving train punctuality by 20%. This was possible thanks to use of advanced signaling systems and real-time monitoring of train movements, powered by 5G networks. Commuters on the line also benefit from seamless and reliable connectivity, which allows them to stay productive or entertained on the train.
Look out for more analysis of mobile network experience around transportation networks in future Opensignal reports. If you are interested in Opensignal solutions for monitoring the mobile network experience around Points of Interest — please reach out to us. To see how Japanese networks fare nationally — check our latest Japan Mobile Network Experience report. Subscribe to our newsletter to stay up to date!
Opensignal reports include main brand experience only, sub-brands are not included. However, Docomo's other price plans (eximo, ahamo & irumo) are included in NTT docomo’s scores.
Our metrics include all user measurements reported across all mobile technologies including when users have exceeded their data allowance. And NTT docomo’s data included 3G.
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