US operator Verizon teamed with Boingo Wireless to bring 5G service indoors, a move that could help fill a critical coverage gap in the operator’s fledgling next-generation network.

The news comes as Verizon continues to roll out its mobile 5G network in cities across the US: it announced Phoenix will become the 10th city to get service on Friday (23 August). It is aiming for deployments in 30 cities by the end of 2019.

While it offers a massive capacity advantage over low-band frequencies, the mmWave spectrum Verizon is using for 5G has trouble penetrating walls, making indoor coverage a challenge.

To address this issue, Verizon and Boingo said they are working to build a “hyper-dense” indoor network of distributed antenna systems (DAS) and small cells. Deployments will span a number of indoor venues, including stadiums, airports, office buildings, hotels and other public spaces.

A Verizon representative told Mobile World Live (MWL) consumers will need a 5G-enabled handset to access service on the indoor networks, but could not provide a timeline for launch.

In July, Boingo CEO Mike Finley told MWL DAS deployments can generally take anywhere from several months to years, depending on the venue.

At the time, Finley noted Boingo has 69 major venues across the country live with DAS: “Every one of those venues we’ll deploy at the carriers’ desire…If 5G goes in those venues we’ll be the one to put it in. So, in that particular part of the ecosystem we’ll play a big role.”

It’s possible more partnership announcements could be on the way. During Boingo’s Q2 earnings call earlier this month, Finley said he had “strategic discussions with executive leadership of each of the tier one carriers” within the last 90 days.

He added: “We believe the opportunities to partner with carriers are greater than perhaps at any time in Boingo’s history.”