Integrated Services Digital Network (ISDN); Subaddressing (SUB) supplementary service; Digital Subscriber Signalling System No. one (DSS1) protocol; Part 4: Abstract Test Suite (ATS) and partial Protocol Implementation eXtra Information for Testing (PIXIT) proforma specification for the user
Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; Support of Mobile Number Portability (MNP); Service description; Stage 1 (3GPP TS 22.066 version 16.0.0 Release 16)
Digital cellular telecommunications system (Phase 2+) (GSM); GSM/EDGE Multiplexing and multiple access on the radio path (3GPP TS 45.002 version 16.1.0 Release 16)
Digital cellular telecommunications system (Phase 2+) (GSM); Universal Mobile Telecommunications System (UMTS); LTE; 5G; Mobile radio interface layer 3 supplementary services specification; Formats and coding (3GPP TS 24.080 version 16.2.0 Release 16)