gsm and 3G shields tutorial :: mobile IoT hardware - j-328GSM3GLader Arduino Pro Mini [adapter board] and c-uGSM / d-u3G / h-nanoGSM shields howto start tutorial - by DRAGOS IOSUB
xyz-mIoT w. EG95A (ARM0 shield + 4G 3G modem ) from itbrainpower.net on Tindie
3G ARDUINO & RASPBERRY PI SHIELD (micro) ** d-u3G 1.13 shield/module/board series :: FEATURES, 3G * GSM * GPRS * DTMF * SMS CODE EXAMPLES and UTILITIES
Cheap Arduino to LAN / WiFi / 3G / 3.5G / 4G connection | Protoneer.co.nz