Comment by apk17

> The network needs to know your location in real time in order to route calls to you.

At least for GSM, that isn't as true as you say it. It only needs to know in wich group of cells you are, as as re-registering with each cell change was deemed too heavy on the battery, and they rather page for your phone in the entire location area.

Likewise, triangulation requires the phone to send something, which means that you can notice that, and also that continuous triangulation will drain your battery.

(Which brings up the question of how often and how smartly google sends updates for the traffic density map.)