= 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 ||
|| AT+CLAC    || List of supported AT commands ||
|| AT+CSQ || Signal strength || 
|| AT+COPS? || Current network operator ||

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

== Send SMS text mode ==
 * picocom -b 9600 /dev/ttyUSB0
 * atz
 * ati
 * at+cmgf=1
 * at+cmgs="960000000"<enter>
 * testSMS<ctrl+z>

== Set GSM number in SIM card ==
 * at+cpbs="ON"
 * at+cpbw=1,"911234567",129,"GSM number"
 * at+cnum #check number

== Set SMS message center ==
 * at+csca="+351911616161",145 #Vodafone Portugal
 * at+csca="+351962100000",145 #TMN
 * at+csca? # check SMS message center


== AT+CSQ signal strength ==
|| Value || RSSI dBm ||	Condition ||
||2	 ||-109	 ||Marginal ||
||3	 ||-107	 ||Marginal ||
||4	 ||-105	 ||Marginal ||
||5	 ||-103	 ||Marginal ||
||6	 ||-101	 ||Marginal ||
||7	 ||-99	 ||Marginal ||
||8	 ||-97	 ||Marginal ||
||9	 ||-95	 ||Marginal ||
||10	 ||-93	 ||OK ||
||11	 ||-91	 ||OK ||
||12	 ||-89	 ||OK ||
||13	 ||-87	 ||OK ||
||14	 ||-85	 ||OK ||
||15	 ||-83	 ||Good ||
||16	 ||-81	 ||Good ||
||17	 ||-79	 ||Good ||
||18	 ||-77	 ||Good ||
||19	 ||-75	 ||Good ||
||20	 ||-73	 ||Excellent ||
||21	 ||-71	 ||Excellent ||
||22	 ||-69	 ||Excellent ||
||23	 ||-67	 ||Excellent ||
||24	 ||-65	 ||Excellent ||
||25	 ||-63	 ||Excellent ||
||26	||-61	 ||Excellent ||
||27	||-59	 ||Excellent ||
||28	||-57	 ||Excellent ||
||29	||-55	 ||Excellent ||
||30	||-53	 ||Excellent ||