ETSI TS 101 251-1998 Digital Cellular Telecommunications System (Phase 2+); Fault Management of the Base Station System (BSS) GSM 12.11 Version 6.0.1 Release 1997
1999ETSI TS 101 251-1999 Digital Cellular Telecommunications System (Phase 2+); Fault Management of the Base Station System (BSS)
1998ETSI TS 101 251-1998 Digital Cellular Telecommunications System (Phase 2+); Fault Management of the Base Station System (BSS) GSM 12.11 Version 6.0.1 Release 1997