The SIM808 GPS/GPRS/GSM Arduino Shield is based on the SIMComm SIM808 all-in-one cellular phone module. Compares to the SIM900 Shield, the SIM808 Shield integrate the GPS function, which makes it more convenient and cost-effective for mobile applications such as cargo monitoring, that you can add location-tracking, voice, text, SMS and data to your project.
Features:
Cold starts: -148 dBm
Accuracy: approx 2.5 meters
Send and receive GPRS data (TCP/IP, HTTP, etc.)
Make and receive voice calls using a headset or an external 32Ω speaker + electret microphone