Investigating the IP future for BBC Northern Ireland

[Brunel]

http://www.bbc.co.uk/rd/blog/2017-02-ip-...rn-ireland

[ppppenguin]

There's a lot of work at present on bringing IP to broadcasting. However it's definitely not simple to replace the established SDI (serial digital interface) infrastructure with IP networking. The first level of the problem is that ordinary uncompressed HDTV needs 1.5Gb/s or 3Gb/s for each signal. 4K uncompressed needs 12Gb/s. These SDI signals are routinely carried in large numbers over ordinary 75R co-ax and optical fibre. They are switched in dedicated routers. In a production environment you want to leave signals uncompressed as far as possible. Sometimes you use a relatively gentle compression system which gives little or no degradation and, even more vital, doesn't have large delays in processing.

The next problem is that in a studio or OB production area everything needs to be very much real time. Accumulating and unpredictable delays as found on IP networks are not acceptable.

And it get even more complicated after that, see for example:
http://www.bbc.co.uk/rd/blog/2016-02-dis...p-studio-1
http://nmos.tv/about_specifications.html

It's still a little while until SDI dies out. By then I will be fully retired and will never have to worry about designing kit with IP interfaces.