1997ETSI ETS 300 393-7-1997 Radio Equipment and Systems (RES); Trans-European Trunked Radio (TETRA); Packet Data Optimized (PDO); Part 7: Security
1996ETSI PRETS 300 393-7-1996 Radio Equipment and Systems (RES); Trans-European Trunked Radio (TETRA); Packet Data Optimized (PDO); Part 7: Security
ETSI PRETS 300 393-7-1997 Radio Equipment and Systems (RES); Trans-European Trunked Radio (TETRA); Packet Data Optimized (PDO); Part 7: Security was changed to ETSI ETS 300 393-7-1997 Radio Equipment and Systems (RES); Trans-European Trunked Radio (TETRA); Packet Data Optimized (PDO); Part 7: Security.