Unstructured Supplementary Service Data (USSD) is a Global System for Mobile(GSM) communication technology that is used to send text between a mobile phone and an application program in the network. Using this service one can collect feedback, participation etc.
USSD supports longer message content than SMS, and is generally considered more responsive. Unlike SMS, USSD is session based. Sessions can be initiated by both users and networks, through varying trigger methods. Commonly used in banking, mobile polling and education, 24X7SMS USSD works best when the need for a highly interactive communication is required.