BARCELONA, Spain—Sprint’s CTO said the carrier plans to add 5G-capable equipment to “tens of thousands” of its towers during the next year or so. John Saw also offered some details about exactly how the carrier plans to go about that work and how it will turn on commercial 5G services.

Importantly, Saw said the carrier won’t offer a “puck” as its first 5G device and will instead wait until a 5G-capable smartphone is ready. He said the carrier expects to sell a 5G-capable phone starting early next year and that “we’re aiming for an iconic-type phone.” He declined to comment on which handset makers would supply the gadget.

But the bulk of Saw’s comments—made during a media event here at the Mobile World Congress trade show—related to how Sprint plans to physically upgrade its network to offer 5G services.

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Saw said the carrier is splitting its 5G buildout work evenly among its three vendors: Ericsson, Nokia and Samsung. Notably, Sprint has raised its 2018 capex expectations to $5-6 billion this year, from a recent low of $2 billion. That could well be more than the estimated $5.3 billion that T-Mobile is expected to spend this year on its own capex. To be clear: Those figures include spending on 5G as well as other network and operational efforts.

During Sprint’s media event, Saw showed off the combined antenna-radio unit from Samsung that the company plans to install on its towers. The unit supports Sprint’s 2.5 GHz spectrum and 64T64R (64 transmit, 64 receive) MIMO.

And Samsung’s Lyle Nyffeler showed off the company’s baseband unit, which will sit at the bottom of those Sprint towers, that will connect to the antenna/radio:

Saw explained that the carrier’s technicians are currently climbing Sprint’s towers to install the antenna/radio unit and the baseband unit and that the company plans to conduct that work on “tens of thousands” of its towers over the course of the next year or so. Saw added though that “not every Sprint site will require massive MIMO capability,” such as those sites in rural areas where there aren’t many users.

Sprint’s Marcelo Claure recently said that Sprint offers 2.5 GHz capabilities on roughly half of its towers today, and the carrier will expand those capabilities to almost all of its towers in the coming year. He also said that Sprint plans to increase the total number of its macro tower sites by around 20%.

According to tower lease consulting company Steel in the Air, Sprint operates roughly 50,000 towers nationwide.

Saw today said that, after Sprint’s technicians install the antenna/radio units and the baseband units, the carrier later will have to install a channel card into the baseband unit in order to turn on 5G services. However, he said that work will cost much less because technicians won’t have to climb the tower in order to install the channel card; instead, they can drive to the base of the tower and install the channel card into the baseband unit at the bottom of the tower.

Then, Saw said, Sprint can activate 5G services through a remote software upgrade. The company has promised to launch its nationwide mobile 5G network in first half of 2019.

Interestingly, Samsung’s Nyffeler explained that the company’s antenna/radio units will be able to support both 5G and LTE services—and will be able to remotely allocate more spectral capacity toward one technology or the other. That means, Nyffeler said, that Sprint will be able to dynamically take 2.5 GHz spectrum away from its LTE network and allocate it to its 5G network as customer demand grows, without technicians having to climb the company’s towers. Saw cautioned that Sprint would likely keep a significant amount of spectrum dedicated to its LTE network since its customers currently use that technology.

Sprint yesterday announced that it plans to turn on 64T64R (64 transmit, 64 receive) Massive MIMO technology in three cities in April.