Siemens Brodersen MC55 AT Command Manual page 269

If no is given or if there is no matching context definition, the MT will attempt to activate the context
<cid>
using the values for PDP type and address provided by the network. The other parameters will be set to their
default values (see AT+CGDCONT).
If activation is successful, data transfer may proceed.
After data transfer is complete, and the layer 2 protocol termination procedure has completed successfully,
the V.250 command state is reentered and the MT returns the final result code OK.
In the event of an erroneous termination or a failure to start up, the V.250 command state is re-entered and
the MT returns the final result code NO CARRIER, or if enabled, +CME ERROR. Attach, activate and other
errors may be reported. It is also an error to issue the
request.
The command may be used in both normal and modem compatibility modes.
MC55_ATC_V04.00
Confidential / Released
command when there is no pending network
AT+CGANS
Page 269 of 475 3/17/06