Google has filed a letter with the FCC back in November of last year, requesting a “Permissive Change” to an FCC ID previously granted on August 31, 2018. Google is basically asking the Federal Communications Commission for permission on adding Band 48 support for Pixel 3 phones with model number G013A. These are basically all internationally available Pixel 3 devices, including those sold via Verizon, except Pixel 3 phones from Japan.
Google specifies that it intends on adding LTE Band 48 support via a software update, which will not require any “hardware change”. In the US, LTE Band 48 operates on 3.5GHz frequency, and it’s a Citizens Broadband Radio Services (CBRS) band.
This frequency is a discontinued government radar frequency that the FCC is now allowing carriers like AT&T, Sprint, and Verizon to make use of. It can be used for 5G, carrier aggregation as well as LTE-Advanced. While there is no timeframe on when the software update will roll out, the frequency is “considered by all US carriers to be used as the core band for 5G development globally”, as GSMArena notes.