The location is taken from an online database based on cell id. It's not clear where most of them get their data but services like wigle and mozilla use crowd sourcing of signal strengths so they might be a bit off. Not as accurate as the ones in the article I would think.

In cdma2000, it's an option. I didn't notice such a thing in LTE. (LTE does include some options to determine position by propagation delay between mobile and base station, but they all involve the mobile reporting time measurements to the network, and then the network has the info to compute location).

Edit: totally wrong. Thanks ectopod8!

I'm pretty sure gps location is derived from signals from GPS satellites and ground stations. You can see this if you're somewhere with no cell signal but have gps, or visa versa.