Network Performance: How Rakuten is scaling a nationwide mobile network

Rakuten Mobile is scaling up its mobile network at unprecedented speed. Commercially launched in April 2020 as the world’s first fully virtualized, cloud-native mobile network built on OpenRAN standards, Rakuten Mobile did what many industry experts said was impossible. And now with Rakuten Mobile’s year-end customer acquisition and performance metrics coming to light, there is much to be celebrated for the telecommunications disruptor.

• Network rollout: Rakuten Mobile is five years ahead of schedule for its network rollout in Japan. While original plans for its radio network included around 8,000 base stations by the end of FY2020, Rakuten Mobile has already deployed over 11,000.
• User experience: Rakuten Mobile customers are among the first in the world to experience a mobile network created on OpenRAN standards. And while doubters have been quick to argue that the technology can’t compete with current mainstream infrastructure, Rakuten Mobile customers are experiencing the fastest upload speeds in Japan at 18.9 Mbps on network vs. an average of other Japan telcos at 8.8 Mbps according to independent Opensignal data. Download speeds are also competitive with other Japanese telcos.
• Customer acquisition: Despite launching a commercial service during a global pandemic, Rakuten Mobile already has received more than 2 million applications, with the majority of applications made online rather than in stores.

Despite Rakuten Mobile’s remarkable progress, there are still challenges that come with launching a nationwide network at speed and scale. One such challenge Rakuten is currently working to overcome is spectrum allocation.

With less than 20% of spectrum assets compared to our competitors, we are doing great. OpenRAN does not mean we have an average network; the truth is that we have a world-class network.

Tareq Amin, Rakuten Mobile CTO

Spectrum challenges for the newcomer

The 4G spectrum allocated to Rakuten Mobile in April 2018 by Japan’s Ministry of Internal Affairs and Communications (MIC) was just 20% of the spectrum held by the incumbent telco operators (20MHz in the 1.7GHz band.) Despite this gap, Rakuten Mobile’s network is delivering competitive performance, with speeds in Tokyo of 36.6 Mbps and 38.0 Mbps in Yokohama in September 2020, according to Opensignal reports.

While Rakuten Mobile was allocated 20MHz of 4G spectrum, rollout in many of the regional centers was initially limited to 5MHz due to the government reallocation process. The company is currently working with the government for clearance to use the full 20MHz in these areas. As more areas switch from 5MHz to 20Mhz, the carrier will see its average speeds increase significantly.

Levels of innovation

Disaggregated radio, unified cloud, massive networking automation and platform organization are four areas where Rakuten Mobile has innovated to ensure network performance. This innovation is at the core of Rakuten Mobile’s network. In addition, to meet the ultra-low latency demands for 5G, Rakuten Mobile has put a strong focus on developing capabilities in edge computing technology.

“The next big opportunity in telecommunications ⁠— and where you can see the discussion that is happening across the world ⁠— is around the edge. The most advanced and largest edge mobile network in the world today exists in Japan, and it exists in Rakuten Mobile. We have deployed thousands of edge data centers,” shared Rakuten Mobile CTO Tareq Amin.

Rakuten Mobile was the first to deploy a large-scale OpenRAN commercial network and the first fully virtualized, cloud-native mobile network.

This innovative network architecture is key to Rakuten Mobile’s ambition plan to cover 96% of Japan population by summer 2021, about five years ahead of the original plan. As noted by Amin, it’s possible to achieve the goal due to the network’s unique network architecture, simplicity, platform and automation, which allows it to build and on-air a base station in less than a day.  

Regarding network performance, Amin explained that success factors are based on virtualization, standardization, optimization and automatizing. Combined, they lead to more cost efficiency, innovation, affordability and growth.

Rakuten Mobile was the first to deploy a large-scale OpenRAN commercial network and the first fully virtualized, cloud-native mobile network. And Amin refutes the perceived limitations of open radio access networks, arguing that Rakuten Mobile’s only limitation today is spectrum assets.

“With less than 20% of spectrum assets compared to our competitors, we are doing great. OpenRAN does not mean we have an average network; the truth is that we have a world-class network,” he added, explaining that once Rakuten Mobile moves from five to 20MHz, there will be a significant improvement in performance, while 5G deployment is also accelerating.

What we’ve done in 4G was enabling a world-first virtualized infrastructure. For 5G, we have a world-first containerized architecture, completely cloud-native radio access software that is (made up of) disaggregated micro services.

Tareq Amin

Ready for 5G

In the 5G realm, Rakuten Mobile has 500MHz of spectrum, a level on par with Japan’s other network operators.

“What we’ve done in 4G was enabling a world-first virtualized infrastructure. For 5G, we have a world-first containerized architecture, completely cloud-native radio access software that is (made up of) disaggregated micro services,” he explained.

“Between LTE, which is 40MHz and about 500MHz of spectrum assets, we think we have a very strong position to be able to increase capacity and demand.”

With data consumption increasing, Rakuten Mobile finds itself uniquely positioned to play a key role in providing connectivity. And with its new, flexible service plan that starts at zero yen and charges based on data usage, Amin is very optimistic about the future. “We’re very confident about our business model and our business plan. And the idea to have zero churn in the network is also a unique value proposition that really emphasizes the critical role of the [Rakuten Mobile] ecosystem and the critical role of data for our long term viability,” said Amin.