Specifications

SIM900 AT Commands Set
SIM900_ATC_V1.01 199 23.06.2010
OK
Establish a context using the terminal
equipment: defines CID 1
and sets the PDP type to IP, access
point name and IP address aren’t set.
AT+CGDCONT=1,
"IP"
ATD*99#
OK
CONNECT
Cancel a context using the terminal
equipment
Pause data transfer and enter Command
mode by +++
Stop the GPRS data transfer
AT+CGDCONT=1,
"IP"
ATD*99#
+++
ATH
OK
CONNECT
OK
OK
Reconnect a context using the terminal
equipment
Resume the data transfer
AT+CGDCONT=1,
"IP"
ATD*99#
+++
ATO
OK
CONNECT
OK
CONNECT
*Quality of Service (QOS) is a special parameter of a CID which consists of several parameters itself.
The QOS consists of
The precedence class
The delay class
The reliability class
The peak throughput class
The mean throughput class
And is decided in “requested QOS” and “minimum acceptable QOS”.
All parameters of the QOS are initiated by default to the “network subscribed value (=0)” but the
QOS itself is set to be undefined. To define a QOS use the AT+CGQREQ or AT+CGQMIN
Command.
Overwrite the precedence class of
QOS of CID 1 and sets the QOS of
CID 1 to be present
AT+CGQREQ=1,2 OK
Response: all QOS values of CID 1
are set to network subscribed except
precedence class which is set
to 2
AT+CGQREQ +CGQREQ:1,2,,,,
+CGQREQ: 3,0,0,3,0,0
OK
Set the QOS of CID 1 to not present.
Once defined, the CID it can be
activated.
AT+CGQREQ=1 OK