Base station sharing gets good reception among mobile carriers


Telecommunications towers are being shared by mobile network carriers to speed up the rollout of 5G, the next-generation communications standard.

The huge capital investment involved in rolling out the fifth-generation communication standard has prompted Japan’s four major mobile carriers to share the base stations needed to operate 5G networks.

If the shift toward infrastructure sharing spreads, network coverage areas will quickly expand, meaning more people will have access to 5G services.

In March, NTT Docomo Inc. announced the sale of as many as 6,002 telecommunications towers for up to about ¥106.2 billion to JTower Inc., which operates shared telecommunications infrastructure.

Once base stations have been installed in the towers, they will provide mobile network coverage over wide areas of Japan.

Docomo plans to pay JTower to use the towers, which is expected to cost less than owning them outright as the fees are likely to decrease if other carriers share the facilities.

Established in 2012, JTower provides base station sharing services in offices, commercial complexes and high-rise apartment buildings, among other indoor locations.

Mobile carriers can reportedly reduce costs by 30% to 50% through sharing of such infrastructure.

JTower will use the facilities acquired from Docomo to develop its outdoor coverage.

Telecommunications firms had focused on installing their own base stations in the past, competing with each other to offer the largest coverage area.

The situation changed dramatically in 2020 with the full-scale introduction of 5G. According to some estimates, four times the number of base stations are required to operate 5G compared to 4G, because the high-frequency radio waves it uses do not travel as far and do not penetrate walls or other structures as easily.

Putting such infrastructure in place requires astronomical amounts of capital investment.

“Rolling out 5G nationwide will cost huge amounts of money and require a lot of effort,” said a senior official at a major telecommunications firm. “We must cooperate with other carriers wherever we can.”

Cooperation within the industry has gained momentum in recent years, with major telecommunications joining hands in 5G projects.

In 2020, KDDI Corp. and SoftBank Corp. established a joint venture to accelerate the sharing of each other’s 5G networks in rural areas.

NTT Group formed a capital alliance with JTower in 2019, and KDDI and Rakuten Mobile Inc. each did likewise in 2021, strengthening the relationships between JTower and the carriers.

However, efforts to pool resources are at an early stage. Only a small percentage of indoor base stations are currently being shared.

The Internal Affairs and Communications Ministry is providing subsidies and other support to operators who share infrastructure to help accelerate the rollout of 5G services.

By around 2030, 5G is likely to be supplanted by the sixth-generation communication standard. As 6G will use radio waves in even higher frequency bands, requiring more base stations than 5G networks, sharing of telecommunications infrastructure is likely to keep expanding.