OnePlus explains what was at the center of the OnePlus 5's 911 rebooting issue

Everyone can surely agree that the issue that caused some OnePlus 5 devices to reboot when dialing 911 was a serious one, albeit one that was addressed by a recent software update. Likely because it was a serious issue, folks understandably wanted to know where that issue came from and what OnePlus did to fix it. That’s something the company has just done on its forums.

According to OnePlus, the issue presented itself whenever someone used Voice over LTE (VoLTE) to call emergency numbers that triggered the OTDOA protocol. Observed Time Difference of Arrival, otherwise known as OTDOA, uses cell towers and measures the amount of time it takes for an LTE signal to reach a tower to determine a phone’s location. Because of this, the emergency number you call can use OTDOA to better get an idea of where your phone is located, so long as the emergency number supports the system.

Where the issue presented itself was in the memory issue that resulted from the obtaining and sending of OTDOA information. As such, the problem was not just in the software, but also in the way the OnePlus 5’s cellular modem talked to the firmware.

As you can imagine, the OTDOA system is an extremely useful tool for emergency numbers to use in order to know where to send help. You can also imagine how dangerous this bug was for those that were affected.

Speaking of which, not every OnePlus 5 was affected by this bug because not everyone makes calls over VoLTE and not every emergency number supports OTDOA. It was still good for OnePlus to address the issue as quickly as it did for those who were affected by it.

If you own a OnePlus 5, you should have received the OxygenOS 4.5.6 hot fix OTA that addresses this 911 rebooting issue. If not, just give it a day or two for your device to receive it.