What is the specific command that will help me identify what type of signal I am receiving (EDGE or GPRS)?

The command 'AT^SMONG' command will tell you if the current network supports GPRS or EDGE. If you do an attach first with 'AT+CGATT=1', then 'AT^SMONG' will tell you if EDGE or GPRS is available.

AT^SMONG command details can be found in chapter 8 of our "AT Command Reference Guide for Edge Wireless Modems". Here is a link to this guide: