This part of IEC 60728 is applicable to optical transmission systems for broadcast signal transmission that consist of head-end equipment, optical transmission lines, in-house wirings and system outlets. These systems are primarily intended for television and sound signals using digital transmission technology. This standard specifies the basic system parameters and methods of measurement for optical distribution systems between headend equipment and system outlets in order to assess the system performance and its performance limits. In this document the upper signal frequency is limited at about 1 000MHz. For systems requiring more bandwidth, IEC 60728-13-1 Ed.2 shall be referred. The purpose of this part of IEC 60728 is to describe the system specifications of FTTH (fibre to the home) networks for digitally modulated broadcast signal transmission. This standard is also applicable to broadcast signal transmission using a telecommunication network if it satisfies the optical portion of this standard. This standard describes RF transmission for fully digitalized broadcast and narrowcast (limited area distribution of broadcast) signals over FTTH, and introduces xPON system as a physical layer media. The detailed description of the physical layer is out of the scope of this standard. The scope is limited to RF signal transmission over FTTH, thus, it does not include IP transport technologies, such as IP Multicast and associate protocols. Some interference descriptions between the telecommunication system and the broadcast 331 system are addressed in Clause 7.