AT&T is asking the Federal Communications Commission (FCC) for a Special Temporary Authority (STA) to conduct drive testing in the 24 GHz band in order to calibrate its propagation models for 5G deployments.
AT&T Spectrum Frontiers, an affiliate of AT&T, was the high bidder in Auction 102 and walked away with 831 licenses covering 383 partial economic areas (PEAs). As part of its application, AT&T said it plans to roll out 5G services on 24 GHz "as soon as practicable," and it’s asking for the STA to facilitate a rapid planned deployment.
“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 operator explained.
AT&T said the proposed operations, which would use spectrum that's already destined to be licensed to its affiliate, pose no tangible risk of interference to any licensed operations, and would promote the public interest by expediting the rollout of 5G services to the public.
Keysight is listed on the application as the supplier of the RF signal generator and Sage Millimeter is to supply the power amplifier.
The 24 GHz auction raised more than $2 billion when it closed earlier this year, with 29 bidders winning a total of 2,904 licenses. AT&T bid over $982 million for its licenses, while T-Mobile pledged over $803 million for its 1,346 24 GHz licenses.
Even though the FCC’s rules for millimeter wave bands were coordinated with federal partners and made public for a long time before the auction, officials from the National Oceanic and Atmospheric Administration (NOAA) were still telling members of Congress in May that 5G deployments using 24 GHz spectrum could negatively impact weather forecasting. The FCC, however, has said it is confident that it can protect passive weather sensors while facilitating widespread 5G deployments.
Millimeter wave bands generally can only transmit signals relatively short distances whereas traditional mid-band or low-band spectrum can transmit signals several miles or more, depending on operators’ technologies and spectrum configurations. However, the higher bands provide great capacity.
New Street Research analysts in a report to investors last week said they believe AT&T’s low frequency 700 MHz D Block spectrum from FirstNet provides excellent coverage, while its mid-band AWS-3 spectrum provides good capacity and coverage and its high frequency WCS provides great capacity.