Sprint has been crowing over its 2.5 GHz spectrum for some time now, but CFO Tarek Robbiati this week gave a slightly more in-depth glance into the central role the band plays in the carrier’s overall strategy.

Speaking at an investor conference on Wednesday, Robbiati said the rollout of 2.5GHz spectrum has “dramatically” improved the carrier’s network and customer experience, which in turn has helped bring churn down. Robbiati said Sprint’s 2.5 GHz spectrum now covers 70 percent of the carrier’s 300 million POPs.

But for Sprint, 2.5 Ghz isn’t just a short-term improvement plan – it’s a long-term vision for the future that has been shaping Sprint’s decision making for some time.

According to Robbiati, Sprint last year bowed out of participation in the current 600 MHz spectrum auction not because it was capital strained, but because scooping up more low-band spectrum doesn’t fit in it’s plan.

“In our mind 2.5 (GHz) is going to be to 5G what 800 (MHz) is to the 4G world. And so when you think about it in those terms building a high capacity network has to start by putting as much high frequency spectrum on air as you possibly can,” Robbiati said. “In the world of 5G, you need to have high frequency spectrum. Why bid for low frequency spectrum? We have plenty of it at 800 and 1900 and that’s enough…we don’t want to be buying just for the spectrum. We are building a network for the future.”

Robbiati said 2.5 GHz is central to Sprint’s overall vision, playing roles in everything from the aforementioned future 5G networks to present-day intra-band carrier aggregation and efforts to relieve congestion.

So far, Sprint’s 2.5 GHz covers around 70 percent of its 300 million POPs, Robbiati said there’s room for further improvement there.

“I think we’ll put eventually all our spectrum holdings on air over time of course as we see fit,” Robbiati said.

Due to the propagation characteristics of high-frequency spectrum, Robbiati said Sprint will continue to densify it’s network. But rather than replacing towers with small cells, Robbiati clarified that small cell sites will be built around the towers as supplemental coverage.

That buildout, he said, will progress in clusters over the next several quarters as Sprint secures the necessary permits.