5G is already available in the United States from most of the carriers including T-Mobile, Sprint, and Verizon. These network carriers have their own set of bands and technology for 5G. For instance, T-Mobile 5G works on multiple bands of wavelength spectrum namely – low-band, mid-band, and high-band. Today, the carrier is expanding 5G support with additional bands for OnePlus OnePlus 7T Pro, the OnePlus 8 and 8 Pro.
T-Mobile is rolling out an update for the supported OnePlus smartphones with additional 5G bands in the United States. As of now, the OnePlus 7T Pro McLaren edition is getting and OTA update with new build Oxygen OS 10.0.35 enabling 5G band 2 and 66. Same goes for the OnePlus 8 5G and the 8 Pro 5G as well with build number Oxygen OS 10.5.8.
Apart from the 5G band 2 and 66 support, the latest Oxygen OS update also features Uplink and Downlink speed improvements. So you can expect better 5G speeds on your OnePlus devices. The rest are general stability improvements and bug fixes.
Here is the screenshot for oxygen OS 10.0.35 update for OnePlus 7T Pro 5G Mclaren Edition:
Here is the Oxygen OS 10.0.8 update for OnePlus 8 5G on T-Mobile: (fixed: OnePlus 8 not 5)
Now, unlike the global variants, the carrier locked smartphones, especially in the United States, the full stock firmware updates are not available to sideload manually via stock recovery. So for the T-Mobile OnePlus phones, you will need to got to settings -> software updates -> and download the OTA update from there.