What is one function of cell phones related to TDOA?

Determining distance to the calling phone is a key function of cell phones related to Time Difference of Arrival (TDOA). This technology utilizes the time it takes for a signal to travel from a cell phone to multiple cell towers to calculate the location of the caller. By measuring the differences in arrival times of the signal at various towers, the system can triangulate the position of the phone, thereby providing critical data for locating individuals, especially in emergency situations.

The other options do not pertain to this specific function. Calculating call costs relates to billing rather than location tracking. Providing contact preferences is about user settings, and starting emergency calls automatically does not involve the distance calculation component that TDOA emphasizes.