Re: ULE encryption Support.

[Gorry Fairhurst <gorry@erg.abdn.ac.uk>]

Just a word or two, to try and help people establish the correct 
context, to communicate...

1) FEC coding is used as a part of physical layer for most media, i.e. 
below the MPEG-2 bit stream.
This type of FEC is NOT the concern of this group and is sepcified by 
others.

2) Coding may also be used above the MPEG-2 TS layer, in some scenarios 
to further improve robustness to
loss (i.e. corruption of the MPEG-2 TS packet stream).  The duplication 
method, discussed in the
"continuity counter" thread is an example of this - albeit rather crude 
from a coding point of view,
and within the transport stream. A "recent" extension to MPE, added the 
optional ability to do more
powerful FEC coding as a part of the encapsulation.

3)  FEC coding may also be done above the transport layer, to protect 
the end-to-end communication
from the effects of packet loss. For more details of such schemes see 
the AVT and RMT WGs of the IETF.

So, (2) is what relates to this WG.

Gorry