= GSM =
GSM (Global System for Mobile Communications, originally Group Spécial Mobile), is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe protocols for second generation (2G) digital cellular networks used by mobile phones. 

== AT command set for GSM Mobile Equipment ==
Adapted from 
 * http://www.etsi.org/deliver/etsi_gts/07/0707/05.00.00_60/gsmts_0707v050000p.pdf (GSM 07.07 Version 5.0.0)
 * http://www.etsi.org/deliver/etsi_ts/127000_127099/127005/04.01.00_60/ts_127005v040100p.pdf (3GPP TS 27.005 Version 4.1.0 Release 4)

||Command || Purpose ||
||ATZ     || Sets all parameters to their defaults ||
||ATI     || Requests manufacturer specific information ||
||AT+GMI     || Requests manufacturer identification ||
||AT+GMM     || Requests model identification ||
||AT+GMR     || Requests revision identification ||
||AT+GSN     || Requests serial number  ||
||AT+CPIN     || Enter PIN  ||
||AT+CMGF     || Message format to use  ||
||AT+CMGL     || List messages  ||
||AT+CMGD     || Delete message ||


== SMS PDU Encode Decode==
http://twit88.com/home/utility/sms-pdu-encode-decode