Rakuten Mobile’s revolutionary cellular network just celebrated its first birthday. But that doesn’t mean work is slowing down; network coverage is expanding faster than ever. In January, Rakuten CEO Mickey Mikitani announced that by summer 2021, the Rakuten Mobile network will reach 96% of Japan’s population ― a target that was originally slated for 2026.
So how is Rakuten Mobile tackling this ambitious challenge? One key part of their solution is drones.
“Since April 2020, Rakuten Mobile has actually been using drones to inspect completed base stations. This new project is the second stage of our drone strategy, in which we use drones to inspect potential antenna sites before we start construction.”Ryuki Uenaka, Unmanned Solution Department, Rakuten
Building out cell coverage from the air
“Between late November 2020 and late January 2021, we employed drones at around 60 different antenna sites around the Kanto area,” says Ryuki Uenaka of Rakuten’s Unmanned Solution Department. “We’re getting ready to expand this initiative into the Kansai region, too.”
This isn’t Rakuten Mobile’s first project with drones and cellular antennas. “Since April 2020, Rakuten Mobile has actually been using drones to inspect completed base stations,” Uenaka reveals. “This new project is the second stage of our drone strategy, in which we use drones to inspect potential antenna sites before we start construction.”
“We can’t afford to be shackled down by ‘common sense’ here. We’re always prioritizing the search for new, different ways to do things, and ― if they look to be effective ― implementing them as quickly as possible.”Erika Shibuya, Base Station Head Office, Rakuten Mobile
Drones are without doubt a novel tool to employ for such a task. But Uenaka and his team aren’t just doing it for thrills: There are many practical advantages that drones bring to the table.
“It’s normally the job of our construction partners to head out to each of the potential sites and inspect them,” explains Erika Shibuya from Rakuten Mobile’s Base Station Head Office “They conduct these inspections to assess whether it’s a good environment in which to construct a base station, or whether the surrounding buildings could block cell reception. We use this data to make informed decisions about building there.”
The logistics surrounding this task can prove more complicated than one might imagine. “It’s often the case that the location of the proposed antenna is on top of a tall billboard, or somewhere equally difficult to access,” she continues. “For these sorts of locations, we would need to build a scaffolding to access the site. For this, we would need to hire a construction team, and then get permission from the owner of the site to build the scaffolding.”
Using drones, however, the team can do away with these lengthy, costly preparations, helping towards achieving the target of some 44,000 locations across Japan by this summer.
“Until now, it had taken us around an hour to inspect each site. But with the drones, we’re done in 10 or 15 minutes,” Shibuya reveals. “If there are several sites clustered together, we can visit 5 or 6 in a single day. And for the 60 or so sites we’ve inspected with drones so far, we’ve seen significant acceleration of the base station deployment process.”
Precise tools for a precise job
Time-save isn’t the only advantage of Rakuten’s futuristic flying machines.
“Say we were building an antenna at a height of 20 meters,” Uenaka poses. “Using a drone, we can gather data from that exact spot, even if there’s nothing there yet. We don’t need to rely on the view from ground level or the instincts of an experienced human worker.”
Not only does this give the team a clear picture of any tall trees or big buildings blocking reception, but it also allows them to check the location of existing antennas perched on nearby roofs.
“Additionally, because we are able to fly up to 50 meters above the construction point, we can capture the entire area for a 360-degree view,” Uenaka continues. “This helps us gain an understanding of the condition of surrounding roads, so that we can plan in advance how we can get trucks and construction vehicles to the site.”
Drones, automation and image analysis technology
“We’re actively discussing how we can automate time-consuming tasks that are difficult for humans to perform visually, such as identifying potential reception blockers like tall buildings and trees, and observing the efficacy of nearby antennas.”Mitsuru Nakazawa, Rakuten Institute of Technology
Rakuten has been working with drones for over five years, conducting countless trials testing everything from autonomous airborne deliveries to drone superhighways. Often, these drone initiatives borrow insight from researchers of the Rakuten Institute of Technology, or RIT.
“Right now at RIT, we’re looking to automate processes like completion inspections and the calculation of optimal antenna angles, making use of our research into AI image analysis,” explains RIT’s Mitsuru Nakazawa. “It’s very likely that RIT’s AI image analysis tech will play a role in these new drone site inspections.”
Automation of tasks that humans cannot perform efficiently is a key focus for Nakazawa and his RIT colleagues. “We’re actively discussing how we can automate time-consuming tasks that are difficult for humans to perform visually, such as identifying potential reception blockers like tall buildings and trees, and observing the efficacy of nearby antennas.”
Harnessing group synergy to hit ambitious targets
For Shibuya, Rakuten’s strong group synergy has helped her team chase their ambitious targets with truly incredible agility.
“We’re making the most of Rakuten’s group synergy with this initiative,” she remarks. “In fact, only a month passed between when we made the first plans and when the first drones lifted off.”
“We’ve brought forward our base station targets significantly in building this network,” Shibuya says. “We can’t afford to be shackled down by ‘common sense’ here. We’re always prioritizing the search for new, different ways to do things, and ― if they look to be effective ― implementing them as quickly as possible.”
This philosophy of embracing the new to chase ambitious targets shines through in another part of the network: On top of Rakuten Mobile’s target of 96% population coverage in Japan by summer 2021, it’s also looking to achieve 100% geographical coverage through the use of low-Earth-orbit satellites.
Amid all this technological excitement, Uenaka is clear about his team’s ambitions: “We want to leverage Rakuten’s group synergy to establish these new drone practices as a world standard in the communications industry.”