ITU-R developed Recommendations for broadcasting systems and IEC did International Standards of receivers
The following table shows an example of digital broadcasting system RECs and their receivers’ International Standards
IEC IEC ITU-R ITU-R IEC 62002-1, 2 IEC 62455 for IPDC/MPEG-TS IEC 62216-1 IEC 62028 IEC 62028 To be included in IEC 62360 IEC 62360 IEC 62360 BT.1833 Multimedia System H BT.1833 Multimedia System C Mobile (One-Seg./DVB-H) BT.1306 System B BO.1516 System A DVB BT.1306 System C BO.1516 System D ISDB Terrestrial Satellite
ITU-T is not the creator of IPTV specifications
ITU-T is combining IPTV specifications made by major IPTV SDOs like:
Three International Standard Organisations under WSC (IEC/ISO/ITU) should have a group, either ad-hoc or standing, for harmonising the Standards by IEC and/or ISO and Recommendations by ITU-T that have possibility to affect significantly to another or all other organisations under WSC in this technical area. The group should consist of Technical Committee level and related Sub-Committee level officers of IEC and ISO and Study Group officers of ITU.
IEC and ISO provides the specifications for equipment, devices and systems of home networks and IPTV receivers sold in retail markets while ITU-T covers access-network protocols, terminals distributed by service operators and a part of requirements for home-networks and end-user devices.