Utilizing 3G/4G connection as gps
You cannot get GPS data without getting GPS data. That's like wanting to get milk from a cow without using a cow.

Some GSM modem modules also include a GPS chip. If yours does you can use that. If not then the closest you can get is:


Country (or maybe city) the IP address is registered in
Cell ID and location of the tower you are communicating with


Both of those are only very rough "somewhere within this square few miles" or "somewhere in this country" kind of data. Any more than that and you need GPS.

Mobile phones augment the GPS / Cell data with WiFi data by matching BSSIDs with an online database (within Google etc) to get rough location information.