USSD (Unstructured Supplementary Services Data) service allows to transfer data between subscribers and applications in real-time mode. At using USSD service you do not have necessity to create number of SMS center at your telephone or to type short message, it is enough to type command which looks like usual call.
Delivery speed of information at using USSD is higher than request through center of short messages and answer time is just 2-4 seconds. In each model of telephone there is a special method of showing USSD and answer.
Service doesn’t require connection and included to basic service suite.