In the latest Mobile Experience Snapshot for Japan, NTT docomo won three of the five categories tested, including highest Excellent Consistent Quality and fastest download speeds. Au had the highest Core Consistent Quality while SoftBank had the most responsive network.
NTT docomo had highest Excellent Consistent Quality
In Common Coverage Areas across Japan, NTT docomo had the highest Excellent Consistent Quality with 88.6% of subscribers having a network experience suitable for use-cases like 1080p video streaming, real-time mobile gaming or HD video calling. Both au and SoftBank were narrowly in second and third place with an Excellent Consistent Quality of 87.8% and 87.2%, respectively.
In regards to Core Consistent Quality, meaning subscribers having a network experience suitable for use-cases like SD video streaming, social media sharing and web browsing, all three operators easily reached the 90% threshold with each operator having a Core Consistent Quality over 94%.
NTT docomo had fastest median download and upload speeds
Despite the close competition in the Consistent Quality metric, the main difference in performance was shown in the download speed test: NTT docomo had the fastest median download speed in Common Coverage Areas across Japan at 34.5 Mbps, while au was in second place with 28.8 Mbps and SoftBank at 27.3 Mbps.
NTT docomo had the fastest median upload speed at 10.4 Mbps, however both SoftBank and au were close behind with median transfer speeds of 9.9 Mbps and 8.6 Mbps, respectively.
SoftBank had best one-way latency result
SoftBank had the most responsive network in Common Coverage Areas across Japan at 14.4 ms. NTT docomo was in second place with a median one-way latency result of 17.5 ms, followed by au in third place at 18.3 ms, 3.9 ms less responsive than first place SoftBank.
Our findings for Japan are based on 110 billion network quality measurements including 8.91 million speed tests between February and April 2021. Our latest complimentary Mobile Experience Report is available to download from the Tutela Insights portal.