User's Manual

16. SUPPLEMENTARY SERVICES
257
LZT 123 7361 R1A
16.17 AT+CUSD Unstructured Supplementary Service Data
This command allows control of the Unstructured Supplementary
Service Data (USSD) according to GSM 02.90. Both network and
mobile initiated operations are supported. Parameter <n> is used to
disable/enable the presentation of an unsolicited result code (USSD
response from the network, or network initiated operation) +CUSD:
<m>[,<str>,<dcs>] to the TE. In addition, value <n>=2 is used to cancel
an ongoing USSD session. If <n> is not given then the default value 0
is taken.
When <str> 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
unsolicited +CUSD: result code.
The interaction of this command with other commands based on other
GSM supplementary services is described in the GSM standard.
Test command returns values supported by the TA as a compound
value.
Some different scenarios are shown below:
• An incoming network initiated USSD-Notify should be presented to
the external application as an unsolicited result code +CUSD: if the
external application has enabled result code presentation.
• An incoming USSD-request asking for a reply should sent to the
external application as an unsolicited result code +CUSD: if the
external application has enabled result code.
• If the external application answers to the request with the command
AT+CUSD then the ME sends the answer to the network.
• A USSD-request sent with the command AT+CUSD from the
external application.
Description Command Possible Responses
Request unstructured
supplementary service
data
AT+CUSD=[<n>[,<str>]] • +CME ERROR: <err>
•OK
Show supported
message types along
with the current service
setting
AT+CUSD? •+CUSD: <n>
•OK
•ERROR
Show list of supported
services
AT+CUSD=? • +CUSD: (list of
supported <n>s)
•OK
•ERROR