T Mobile has begun testing its version of the Android 6.0 Marshmallow update for owners of the Samsung Galaxy S6 and S6 Edge on its network. The carrier has officially moved the software upgrade from the manufacturer development phase to the testing phase on its official support page, indicating final release of the update is imminent.
The only U.S. carrier whose customers have received the update so far is Sprint, which released the Android 6.0 Marshmallow update for Samsung Galaxy S6 and S6 Edge owners on its network earlier this month. Verizon and AT&T have yet to release the upgrade, even though AT&T had a scheduled release date this month for the former Samsung flagships that was not met and has since passed.
That doesn't mean that either of those carriers won't beat T-Mobile to the punch in the actual release of the Android 6.0 Marshmallow update for the Samsung Galaxy S6 and S6 Edge. T-Mobile's rivals don't generally pre-announce the release of Android software updates, nor do they offer official progress reports on their eventual release. That means that either Verizon or AT&T could be releasing the Android 6.0 Marshmallow update for the Galaxy S6 and S6 Edge ahead of T-Mobile.
T-Mobile is the only U.S. carrier that officially reports three software upgrade stages: Manufacturer Development, T-Mobile Testing and Completed. "Manufacturer Development" indicates that the carrier is in the process of creating the update for a particular handset. "Testing" indicates that the development process is complete and that the upgrade is being checked for quality and consistency before being released to the carrier's customers before being moved to the third and final phase, "Completed," upon which it is released to customers.
Previously, the Samsung Galaxy S6 and Galaxy S6 Edge were stuck in the first phase of the development program (where the Samsung Galaxy S6 Edge+ still remains) but now that they have moved into phase two, it appears the Android 6.0 Marshmallow update for both former Samsung flagship smartphones is on the horizon. The actual release date is unclear, but history indicates that, once a device moves into phase two of T-Mobile's development process, it should be ready for release within a matter of a couple weeks, unless there are any unforeseen issues or delays.