Multi-Tech Systems GPRS (MTMMC-G) Benutzerhandbuch

Chapter 10 – Supplementary Services Commands  

Multi-Tech Systems, Inc. Wireless GSM/GPRS AT Commands (Document Number S000293I) 

90 

 

Description: 

The USSD supplementary service is described in GSM 02.90. It is based on sequences of digits which 
may be entered by a mobile user with a handset. A sequence entered is sent to the network which 
replies with an alphanumerical string,  for display only, or for display plus request for the next sequence.  

 

This command is used to: 

• 

Enable or disable the CUSD indication sent to the application by the product when an incoming 
USSD is received 

• 

Send and receive USSD strings 

 
0  Disable the result code presentation  
1  Enable the result code presentation 
2  Cancel session (not applicable to read command response) 

<m>  

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 
4  Operation not supported 

<str> is network string, converted in the selected character set 
<dcs> is the data coding scheme received (GSM TS 03.38). 

syntax:  AT+CUSD = <n> [ ,<str> [ <dcs> ] ] 

Note:  In case of enabled presentation, a +CUSD (as direct answer to a send 

USSD) is then indicated with: 

                +CUSD: <m> [,<str>,<dcs> ] 

Command Syntax To Send and Receive USSD:   AT+CUSD= <n> [,<str> [,<dcs>]] 

Note:  Please be aware that the send USSD command needs the user to re-enter 

the <n> parameter! 

<str>  The USSD string to be sent. 
<dcs> The default alphabet and the UCS2 alphabet are supported. 

When the product sends a USSD, an OK response is first returned, the 
intermediate +CUSD indication comes subsequently. In case of error, a +CUSD: 
4 indication is returned.