Rakuten Mobile is deploying 1Finity 5G radios across its Japanese network, extending an Open RAN rollout that has made the operator the most closely watched test case for disaggregated radio gear in a major developed market.

The deployment, reported by Data Center Dynamics, deepens Rakuten Mobile's dependence on Open RAN architecture at a moment when the wider industry is still debating whether the approach can match the cost and performance of conventional single-vendor networks. No coverage targets, site counts or financial terms accompanied the announcement.

What is actually being deployed?

The 1Finity radio line is the Open RAN hardware portfolio built to interoperate with compliant baseband and RAN software from other suppliers. For Rakuten Mobile, that means radios from one vendor feeding a cloud-native, virtualized network core and RAN stack assembled from multiple vendors — the defining feature of the Open RAN model.

Rakuten Mobile launched its commercial 4G network in 2020 as a fully virtualized, Open RAN build, a first for a national operator of its scale in Japan. The subsequent 5G rollout followed the same architecture. Each additional radio deployment, including the 1Finity units now in progress, is an incremental step in that single-vendor-replacement strategy rather than a new direction.

The operator's pitch has been consistent: multivendor Open RAN should lower equipment costs and loosen the grip of the traditional radio incumbents. Whether that saving survives contact with integration overhead is the question every rival operator watching Rakuten is still trying to answer.

How solid are the claims?

The announcement itself is thin on verifiable detail. There are no subscriber figures attached, no base-station counts, no throughput benchmarks and no deployment timeline in the public statement.

That absence matters because Rakuten Mobile's Open RAN experiment has always carried a dual identity: an engineering program on one side, a marketing argument for the Open RAN ecosystem on the other. Vendor-aligned coverage of each rollout milestone tends to emphasize momentum; the commercial results arrive separately, in quarterly financials, and those have told a more complicated story about subscriber growth against Japan's entrenched triopoly of NTT Docomo, KDDI and SoftBank.

A radio deployment is real capital expenditure. It signals the network is still being built out. But a parts-order narrative is not the same as evidence that Open RAN is cheaper at scale — a distinction worth holding onto every time a deployment headline appears.

Why the regulatory and standards backdrop matters

Rakuten Mobile's build has drawn attention beyond Japan because governments in the US, UK, India and parts of Europe have promoted Open RAN as a route to vendor diversification in 5G radio access networks. The O-RAN Alliance specifications that make multivendor interoperability possible are mature enough for live national deployments — Rakuten's network is the standing proof of concept — yet most large operators have moved far more cautiously, confining Open RAN to greenfield networks, rural coverage obligations or limited trials.

Japan's regulator has not mandated Open RAN adoption, so Rakuten Mobile's choices remain commercially driven rather than policy-driven. That makes the operator's results a cleaner read on the technology's economics than deployments in markets where governments subsidize or require it.

What comes next

The near-term question is pace: how quickly the 1Finity radios translate into additional 5G coverage and capacity, and whether Rakuten Mobile discloses site numbers or coverage milestones as the rollout proceeds. The longer-term question is whether the operator's cost structure, once the build matures, shows the savings that Open RAN's advocates have promised since the first radios went live. Until those numbers appear, the deployment is a signal of continued investment — not yet a verdict.

By Rebecca Stone