unstructured supplementary service Data USSD

UDT Unstructured Data Transfer

Unstructured data

unstructured data item

product-supplementary service(PSS)

Supplementary Service

supplementary service interrogation

supplementary service interworking

supplementary service registration

3G Data Service Testing

Application service data unit

ATM data service unit

automatic data service center

B-ISDN Broadband – Integrated Service Data Network

Broad band Integrated Service Data Network (B-ISDN)

Broadband Data Service

chemical data service

connectionless broadband data service

DATA SERVICE