Specifications

Chapter 11 – GPRS Commands
Multi-Tech Systems, Inc. AT Commands for EDGE Modems (S000371B) 166
11.22 Using GPRS AT Commands (Examples)
Example 1 – Defining and Using a Context Definition ID (CID):
Every time a CID is used as a parameter for a GPRS command the CID has to be defined before by using the
AT+CGDCONT command. To get the parameter of a CID use the AT+CGDCONT read option. If the response of
‘AT+CGDCONT?’ is OK only, there is no CID defined.
AT+CGDCONT?
OK There is no CID defined
All parameters of the CID are initiated by NULL or not present values, and the CID itself is set to be undefined.
To define a CID use the AT+CGDCONT command with at least one CID parameter. At the moment the mobile
supports CID 1 and CID 2 by using the AT+CGDCONT command.
Define CID 1 and set the PDP type to IP, access point name and IP address are not set:
AT+CGDCONT=1,”IP”
OK
Define CID 2 and sets PDP type, APN and IP addr:
AT+CGDCONT=2,”IP”, “internet.t-d1.gprs”, 111.222.123.234
OK
A following read command will respond:
AT+CGDCONT?
+CGDCONT:1,”IP”,””,””,0,0
+CGDCONT:2,”IP”,”internet.t-d1.gprs”,111.222.123.234
OK
Set the CID 1 to be undefined:
AT+CGDCONT=1
OK
A following read command will respond:
AT+CGDCONT?
+CGDCONT:2,”IP”,”internet.t-d1.gprs”,111.222.123.234
OK
Example 2 – Quality of Service (QoS) is a special CID parameter that consists of several parameters itself:
• the precedence class
• the delay class
• the reliability class
• the peak throughput class
• the mean throughput class
It is also divided 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 set the QoS of CID 1 to be present:
AT+CGQREQ=1,2
OK
A following read command will respond:
AT+CGQREQ?
+CGQREQ: 1,2,0,0,0,0
OK
All QoS values of CID 1 are set to network subscribed now, except precedence class which is set to 2. Now set
the QoS of CID 1 to not present:
AT+CGQREQ=1
OK
Once defined, the CID it can be activated. To activate CID 2 use:
AT+CGACT=1,2
OK
If the CID is already active, the mobile responds OK at once.
If no CID and no STATE is given, all defined CIDs will be activated by:
AT+CGACT=
OK
If no CID is defined the mobile responds +CME ERROR: invalid index.
Remark: If the mobile is NOT attached by AT+CGATT=1 before activating, the attach is automatically done by
the AT+CGACT command.
After defining and activating a CID it may be used to get online by:
AT+CGDATA=”PPP”,1
CONNECT The mobile is connected using the parameters of CID 1.