DVB-C2 in Japan


As part of the build-up to the 2020 Tokyo Olympics, some Japanese satellite broadcasters will begin UHD broadcasts and an experimental Super Hi-Vision (8K) service in 2016. The Japanese government would like to use DVB-C2 for the redistribution of UHD and Super Hi-Vision TV. 

In Japan it is common for satellite (and terrestrial) broadcasts to be redistributed via cable TV networks to homes that otherwise are difficult to reach, e.g., in mountainous or dense urban areas.

The current Japanese cable TV physical layer standard is ISDB-C or J.83/C. This is identical to DVB-C except for channel bandwidth (6MHz instead of 8MHz) and roll-off factor. As a first generation cable specification it does not offer the capacity to redistribute UHD or Super Hi-Vision TV.

Thanks to the efforts of the chairman of the Technical Module for C2, DVB-C2 became an international standard (J.382) and so the Japanese government would like to use this for the redistribution of UHD and Super Hi-Vision TV. However, some minor modifications are required to make it suitable for use in Japan. A request was made to DVB (via Sony Corporation) to consider the changes and approval to start work was given by the DVB Steering Board in July 2014.

The enhancements are; (i) signalling for Emergency Warning System, (ii) a new MODCOD combination allowing greater flexibility and (iii) clarification of the details of PLP bundling allowing the use of 2 (or more) 6MHz channels to achieve the target capacity of 100Mbps.

The Commercial Requirements have been drafted in the Commercial Module for C2 and submitted to the DVB Commercial Module for approval. The target is to have the enhanced DVB-C2 specification ready for approval at the Steering Board meeting in February 2015.