27.0073GPPAT command set for User Equipment (UE)Release 18TS
Table 125: +CGANS action command syntax
+CME ERROR: <err>
+CGANS: (list of supported <response>s),(list of supported <L2P>s)
NOTE: The syntax of the AT Set Command is corrected to be according to ITU‑T Recommendation V.250 . Older versions of the specification specify incorrect syntax +CGANS=[<response>,[<L2P>,[<cid>]]]
The execution command requests the MT to respond to a network request for Packet Domain PDP context activation which has been signalled to the TE by the RING, +CRING or +CGEV unsolicited result code. The <response> parameter allows the TE to accept or reject the request.
If <response> is 0, the request is rejected and the MT returns OK to the TE.
If <response> is 1, the following procedure is followed by the MT.
Commands following the +CGANS command in the AT command line shall not be processed by the MT.
If the <L2P> parameter value is unacceptable to the MT, the MT shall return an ERROR or +CME ERROR response. Refer clause 9.2 for possible <err> values. Otherwise, the MT issues the intermediate result code CONNECT and enters V.250 online data state.
The detailed behaviour after the online data state has been entered is dependent on the PDP type. It is described briefly in 3GPP TS 27.060  and in more detail in 3GPP TS 29.061  and the specifications for the relevant PDPs. PDP context activation procedures shall take place prior to or during the PDP startup.
One or more <cid>s may be specified in order to provide the values needed for the context activation request.
During the PDP startup procedure the MT has the PDP type and the PDP address provided by the network in the Request PDP Context Activation message. The MT may also have some or all of the following information:
The MT may have a priori knowledge, for example, it may implement only one PDP type.
The command may have provided an <L2P> parameter value.
The TE may provide one or both of PDP type and PDP address to the MT in the PDP startup.
If any of this information is in conflict, the command will fail.
If one or more <cid> is given then an attempt shall be made to identify an appropriate context definition by matching the PDP type and PDP address in the network request with the PDP type and PDP address in each of the specified context definitions (in the order in which their <cid>s appear in the command) as follows:
The PDP type must match exactly.
The PDP addresses are considered to match if they are identical or if the address in the context definition is unspecified.
The context shall be activated using the values for PDP type and PDP address provided by the network, together with the other information found in the PDP context definition. An APN may or may not re required, depending on the application.
If no <cid> is given or if there is no matching context definition, the MT will attempt to activate the context using the values for PDP type and PDP address provided by the network, together with any other relevant information known to the MT. The other context parameters will be set to their default values.
If the 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 re-entered and the MT returns the final result code OK
In the event of an erroneous termination or a failure to startup, the V.250 command state is re-entered and the MT returns the final result code NO CARRIER or, if enabled, +CME ERROR. Refer clause 9.2 for possible <err> values. Attach, activate and other errors may be reported. It is also an error to issue the +CGANS command when there is no outstanding network request.
NOTE: This is not the same as if the MT issues a +CGDATA (or +CGACT) command after receiving a +CRING unsolicited result code. A +CGDATA (or +CGACT) does not command the MT to acknowledge the network request but rather to make a new request for context activation. The network request would be ignored.
The test command returns the values of <response> and <L2P> supported by the MT as compound values.
This command may be used in both normal and modem compatibility modes.
<response>: integer type; specifies how the request should be responded to.
0 reject the request
1 accept and request that the PDP context be activated
If <response> is omitted it is assumed to be 0.
<L2P>: string type; indicates the layer 2 protocol to be used (see +CGDATA command).
<cid>: integer type; specifies a particular PDP context definition (see the +CGDCONT and +CGDSCONT commands).