FIELD: information technology.
SUBSTANCE: invention relates to processing service of unstructured supplementary service data (USSD). For this purpose, when an applications server determines that UE in a VoLTE network supports USSD operations on multimedia IP subsystem of core network, applications server sends an invitation message to UE via a CSCF element, where invitation message contains a USSD service identifier; response to invitation is obtained, where response to invitation sends UE through CSCF element and it contains information with a response, input by a subscriber, and information with response includes a USSD service identifier; generating, in accordance with information with a response, a message which requests execution of a USSD service, where message, which requests execution of USSD service, contains a USSD service identifier; and sending to subscriber data server a message which requests execution of USSD service and which is generated by a generation unit, so that subscriber data server processes USSD service in accordance with USSD service identifier contained in message, which requests execution of USSD service.
EFFECT: possibility of starting USSD from side of existing network to side o UE of voice transmission network VoLTE.
16 cl, 10 dwg
