OnePlus 5 and OnePlus 5T are receiving the latest OxygenOS 5.1.6 software update which brings support for 4G VoLTE on Idea Cellular's network in India, improved Bluetooth stability for phone calls, the latest Android security patch, and official support for Project Treble. Notably, while support for Project Treble was spotted in the last OxygenOS 5.1.5 update, this is the first update where OnePlus has acknowledged its official rollout. The company also announced that it is working on the Android 9.0 Pie software update for the OnePlus 5 and OnePlus 5T, and said that “a big update is on its way”.
The changelog of the minor OxygenOS 5.1.6 lists Project Treble support, VoLTE on Idea's network in India, improved Bluetooth stability for phone calls, and support for the latest October 2018 Android security patch. Project Treble was rolled out in OxygenOS 5.1.5 as per reports earlier, however OnePlus has officially acknowledged its support in this update. Only users running OxygenOS 5.1.5 will be able to upgrade to the latest build.
Project Treble, launched by Google in May last year, allows Android smartphone OEMs to swiftly release latest Android software updates without any major tweaks. Project Treble creates a separate vendor interface between the Android OS framework and the vendor implementation. This allows for the elimination of the default wait-in period required for manufacturers to modify the software specific to the hardware.
As noted previously, a Project Treble update for these two phones is surprising considering OnePlus had itself stated that it does not have plans to support Project Treble on the OnePlus 3, 3T, 5, or 5T.
This OTA is supposed to have a staged rollout, as in it will roll out to a limited number of users initially followed by a broader rollout in the next few days. This is usually done to get rid of any critical bugs during the initial days. Using a VPN might not work as the rollout is not based on regions and is randomly pushed to a limited number of handsets.
Additionally, Manu J, Staff Member, Beta Program and Developer Relations, OnePlus in a comment on the forum post, said, “Hi there, a relatively minor update for this time, but Project Treble is still a great news! Our software team is focusing on the Android Pie update for OnePlus 5/5T. A big update is on its way.”