GSM
The ETSI GSM 07.07 (3GPP TS 27.007) specifies AT style commands for controlling a GSM phone or modem. The ETSI GSM 07.05 (3GPP TS 27.005) specifies AT style commands for managing the SMS feature of GSM.
Examples of GSM commands:
| Command | Description |
|---|---|
| AT+CPIN=1234 | Enter PIN code |
| AT+CPWD="SC","old","new" | Change PIN code from 'old' to 'new' |
| AT+CLCK="SC",0,"1234" | Remove PIN code |
| AT&V | Status |
| ATI | Status (Manufacturer, Model, Revision, IMEI, capabilities) |
| AT+COPS=? | List available networks 0-Unknown/2-Current/3-Forbidden, Longname, Shortname, Numerical-ID, "AcT" |
| AT+CSQ | Get signal strength. Answer: +CSQ: |
| ATD*99# | Dial access point |
| AT+CGDCONT=1,"IP","access.point.name" | Defines PDP context. |
GSM/3G modems typically support the ETSI GSM 07.07/3GPP TS 27.007 AT command set extensions, although how many commands are implemented varies.
Most USB modem vendors, such as Huawei, Sierra Wireless, Option, have also defined proprietary extensions for radio mode selection (GSM/3G preference) or similar. Some recent high speed modems provide a virtual Ethernet interface instead of using a PPP connection for the data connection because of performance reasons (PPP connection is only used between the computer and the modem, not over network). The set-up requires vendor-specific AT command extensions. Sometimes the specifications for these extensions are openly available, other times the vendor requires an NDA for access to these.
Read more about this topic: Hayes Command Set