Quectel EC25 Command Manual page 188

When <reqstr> is given, a mobile initiated USSD string or a response USSD string to a network initiated
operation is sent to the network. The response USSD string from the network is returned in a subsequent
+CUSD URC.
AT+CUSD Unstructured Supplementary Service Data
Test Command
AT+CUSD=?
Read Command
AT+CUSD?
Write Command
AT+CUSD[=<mode>[,<reqstr>[,<dcs>
]]]
Maximum Response Time
Reference
3GPP TS 27.007
Parameter
<mode> Integer type. Sets/shows the result code presentation status to the TE
0 Disable the result code presentation to the TE
1 Enable the result code presentation to the TE
2 Cancel session (not applicable to Read Command response)
<reqstr> Unstructured Supplementary Service Data (USSD) to be sent to the network. If this
parameter is not given, network is not interrogated.
<rspstr> Unstructured Supplementary Service Data (USSD) received from the network
<dcs> Integer type. 3GPP TS 23.038 Cell Broadcast Data Coding Scheme (default 15)
<status> USSD response from the network or the network initiated operation
0 No further user action required (network initiated USSD Notify, or no further
information needed after mobile initiated operation)
1 Further user action required (network initiated USSD Request, or further
information needed after mobile initiated operation)
2 USSD terminated by network
3 Another local client has responded
4 Operation not supported
5 Network time out
EC25&EC21_AT_Commands_Manual
Response
+CUSD: (list of supported <mode>s)
OK
Response
+CUSD: <mode>
OK
Response
OK
ERROR
If there is any error related to ME functionality:
+CME ERROR: <err>
120s, determined by network.
LTE Module Series
EC25&EC21 AT Commands Manual
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