OnePlus explains the bug that tripped up emergency calls last week
It wasn’t just an issue with OnePlus 5 units, though, as some users reported that OnePlus 3T units as well as phones from ASUS, Samsung, Sony and other Android OEMs are affected by this risk-induced problem. It was a sporadic issue, too, as some units of a certain model got hit while others didn’t have it.
OnePlus wrote up a post yesterday on its forums explaining that it has to do with E911 calls.
The source of this issue was related to a modem memory usage issue that triggered a reboot. This reboot was a random occurrence for some users on VoLTE network where OTDOA protocol was triggered when placing an emergency call.
We have worked with our partners at Qualcomm to resolve this issue globally.
OTDOA is a location protocol that pulses data to the dispatch center on enhanced 911 transmissions. Perhaps this data was not getting sent and was just left to overflow its buffer, but we don’t have those specific details. We also aren’t exactly clear if failed AOSP code had to bridge location data through to the modem or if it’s entirely on Qualcomm’s side.
But the sooner manufacturers can sort this out, the better.