AT&T has asked the Federal Communications Commission (FCC) for early access to millimeter wave (mmWave) spectrum in won in a recent auction in an attempt to boost its 5G plans. The carrier also signed a new tower leasing agreement that it says will help those efforts.

The carrier has asked the FCC for early access to some of its 24 GHz spectrum to begin conducting “calibration testing.” As part of the filing, AT&T said it plans to “roll out 5G services on 24 GHz as soon as practicable.”

“Although AT&T has developed network planning models for 24 GHz, the band is new and the propagation models will need to be tuned for specific combinations of terrain and clutter/land use,” the carrier wrote.

AT&T picked up hundreds of 24 GHz spectrum licenses for nearly $1 billion during the FCC’s recently completed auction process.

AT&T’s initial 5G deployment is reliant on the carrier’s mmWave spectrum, with a specific focus on spectrum in the 39 GHz band. That spectrum is powering the carrier’s current 5G deployments that is available in parts of 21 markets.

The “parts of” aspect of that coverage is because of the limited propagation – or reach – of mmWave spectrum compared with lower band spectrum. Initial testing has shown mmWave spectrum bands are limited to less than a kilometer of reach from an antenna compared with several kilometers for lower spectrum bands. The mmWave bands also have a harder time penetrating obstacles like walls and foliage.

While the reach is limited, there is a lot of mmWave spectrum available that allows for much higher data speeds. Carriers typically have less than 100 megahertz of low-band spectrum, while they are lining up to have hundreds of megahertz of mmWave spectrum.

AT&T’s plans to cover around 200 million potential customers by the middle of next year with 5G service will rely on the carrier mixing in support from its lower-band spectrum holdings. This model is similar to what T-Mobile US is planning to do for its nationwide 5G plans.

AT&T today also signed a new tower leasing agreement with American Tower that should help boost those 5G plans.

The “long-term agreement” involves a “simplified leasing process and expanded site development services.” These will support the carrier’s need to install new equipment at those sites to support 5G and its FirstNet public safety network.

“This is essential for executing on both our 5G and FirstNet network builds,” explained JR Wilson, VP of tower strategy and roaming at AT&T, in a statement. “It ultimately helps us better serve our customers and first responders nationwide.”

AT&T has been installing new equipment at its cell towers that will allow it to upgrade those sites to support 5G services through a software update.