Don't need login... All network devices have a MAC adresse... Use this as ID.
Note: IP adresses can be translated mistankenly... If a segment of the IP ranged is owned by a Sweedish company, but a subnet of the same segment is used in Norway... It will still report back as Sweeden!
GSM Triangulation is the phone messuring signal strength from the radio masts it have connection to. This, with poor GPS signals can give a very accurate location.
PS: Triangulation "navigation" can be thrown off if there's something interfering with the signal, making it weaker than it actually are. Making the phone think it's further away from the mast than it really is.