Using a GSM Module instead of telemetry modules for communication between QGroundControl and px4

Hello Everyone,
I am new to px4. I was developing a drone with raspberry pi and navio2 using px4 and QGroundControl. I have already made communications between px4 and qgroundcontrol using UDP(wifi communication) and telemetry devices etc.

Now i want to communicate between px4 and qgroundcontrol using a GSM Module(eg: SIM900, SIM800 etc). For that how to begin with? Please help me with that.

Thanks in Advance for the Answers

I’m also looking for this solution to integerate GSM Module with QGC