AAC has been standardized by ISO and IEC, as part of the MPEG-2 and MPEG-4 specifications.[3][4] Part of the AAC known as High Efficiency Advanced Audio Coding (HE-AAC) which is part of MPEG-4 Audio is also adopted into digital radio standards like DAB+ and Digital Radio Mondiale, as well as mobile television standards DVB-H and ATSC-M/H.