I am using a GSM modem to send data to a remote server over TCP/IP connection. I am using STM32F103 for the software. I want to connect 3 LED's with the 'F103 to indicate which connectivity and service level is provided by my Tel-co for the current connection.. 2G or 2.5G or 3G (or maybe 4G also). 

How can I do this? do I need to measure the RSSI signal strength for this or do I need to measure some other parameters?

Edit:

I am using M95 Modem. 
My understanding is that if RSSI level is low that I will get lower speed connectivity to the server (lower data rate possible) and more chances of corrupt packets and data loss. So when I will be at 2G or 2.5G then I will not send or request big data files to and from the server as it will not complete successfully even after many retries. But if I get 3G connection from the Tel-co then I will do bigger files send or receive tasks. This is my vague understanding. Please correct me if I am wrong in it.