Rakuten Mobile and its Network Experience

At its Q2 2020 Earnings virtual event, Rakuten Mobile took an opportunity to share the performance results of its four-month-old Altiostar-based Open RAN 4G network.

One of the data points presented came from Opensignal, the global standard for understanding the true state of the world’s mobile networks based on measurements of real user experience. Their analyst team has recently published a report detailing one of the first tests of 4G subscriber throughput on the Rakuten mobile network in comparison to other nationwide 4G operators in Japan, demonstrating very promising results – so promising that Rakuten Mobile included the results in the their earnings report.

According to Opensignal, when users are on the 4G network, they are experiencing very good download speeds with the Rakuten network providing great network availability and plenty of bandwidth for applications such as online gaming, video and voice and as seen in the chart below:

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This is despite Rakuten, as a new operator in the market, being constrained in terms of having 1/6 the spectrum holdings of its competitors. Other operators in market such as NTT DoCoMo, KDDI’s au and SoftBank have been able to build up much more spectrum over the years, which contributes to their download performance. As Rakuten adds more spectrum holdings, we can expect the download performance of the network to meet or exceed the other operators.

In terms of 4G upload speeds, Rakuten is actually outperforming other operators and this is in part due to the superior performance of the open vRAN solution they are using from Altiostar, including patented algorithms which allow operators to realize gains in performance.  In addition, customers such as Rakuten benefit from Altiostar’s focus on R&D, state of the art tools and RF measurement equipment, and implementation methodology, which has been field-tested and fine-tuned to allow for improved network performance.

These performance numbers were backed up by a separate blog post from Tutela in October 2020, which reports performance based on crowdsourced data. Some of the conclusions of that report include:

  • Rakuten users experienced higher upload speeds and better latency compared to some other operators, which may prove to be important elements for Rakuten’s success. With the world being in a lockdown, these are critical factors for some important use-cases like gaming and uploading content on social media platforms.
  • The high-quality user experience provided by Rakuten’s own network, and its rate of adoption by users, suggests that so far, the O-RAN deployment is working well.

Rakuten focused its initial deployment on three cities, Tokyo, Nagoya and Osaka, where there is the need for high performance in a very dense urban environment. Per Opensignal, “these high speeds indicate the potential of Rakuten’s network to enable a tremendous mobile network experience even at this early stage.”

Another critical factor is how stable the network is despite the rapid rate of new subscriber growth. The chart below shows the rapid daily growth in new subscribers in the red bars, with the green line demonstrating the stable downlink throughput in the face of that growth.  That performance matches with network quality metrics of availability, accessibility, and retainability.

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As the first commercially launched cloud-native vRAN based 4G network, Rakuten has been closely watched by industry observers looking to glean insight into the Open vRAN movement led by Altiostar. As these reports and its own numbers indicate, Open vRAN provides the same or better level of 4G performance as that of a traditional mobile network. With the launch of the Rakuten 5G network at the end of September 2020, we can expect to see more details on the network’s performance in the coming months. There are also additional Open vRAN deployments in the works in the US, India, Germany, Spain and elsewhere, where we will soon see more proof points toward the viability of a truly open and virtualized RAN.

About The Author
Jason King Director of Marketing