"READY. Note: this is SIM900A module witch support two band:900/ 1800MHz.
If you need Quad band support: 850/900/1800/1900MHz here is link:
Hook your Arduino up to GSM/GPRS cell phone network with GPRS shield! You can use your Arduino to dial a phone number or send a text to your friend via easy to use AT commands now. This new version features a quad-band low power consumption GSM/GPRS module SIM900A as well as a compact PCB antenna. Meanwhile, improvements on interfaces and basic circuit have been taken to make it more concise and reliable.
Compatible with standard Arduino and Arduino Mega
Selectable interface between hardware serial port and software serial port
Quad band support: 900/1800MHz
Support TCP/UDP protocols
Full control via AT commands set: Standard - GSM 07.07 & 07.05 and Enhanced - SIMCOM AT Commands
2-in-1 headset jack
Convenient external SIM card holder
Low power consumption: 1.5mA(sleep mode)
Make sure your SIM card is activated.
GPRS Shield doesn't come with ESD precautions. Take special care when handling it in dry weather.
The factory default setting for the GPRS Shield UART is 19200 bps 8-N-1. (Can be changed using AT commands).
Please visit our wiki page for more info about this product. It will be appreciated if you can help us improve the documents, add more demo code or tutorials. For technical support, please post your questions to ourforum.