RE: ULE and FEC

["Bernhard Collini-Nocker" <bnocker@cosy.sbg.ac.at>]

Hello,

since I am on holidays :-) I take the chance to be more active in this
discussion group.

Well, FEC is a very good point, and the need for it in DVB-T is certainly
existing. My question, apart from whether or not to add a FEC type, at
this point is, what error patterns are being considered. We also have a
DVB-T set-up running in our lab and the probability that packets (SNDUs)
can be corrected with FEC and interleaving alone is from my experiences
rather low, given that outages (link losses during station movements)
are typically affecting quite many TS cells corresponding to many SNDUs
and, hence, retransmissions are needed to maintain reliability.

Best regards,
Bernhard

> -----Original Message-----
> From: owner-ip-dvb@erg.abdn.ac.uk [mailto:owner-ip-dvb@erg.abdn.ac.uk]On
> Behalf Of Benoit Oger
> Sent: Mittwoch, 25. Februar 2004 10:38
> To: ip-dvb@erg.abdn.ac.uk
> Subject: ULE and FEC
>
>
> Hello,
>
> as new subjects are raised, like encryption, I was thinking it could be
> interessant for ULE to propose a FEC system (Forward Error
> Correction). ULE
> is aimed for a wide range of physical media, more or less exposed to noise
> and error; therefore an error correction ability could be useful.
> Actually,
> we could be inspired by the DVB-H draft that provide MPE with
> such a system,
> called MPE-FEC. DVB-H derive from DVB-T standard, it deals with
> optimisation
> for wireless communication like the reduction of the average power
> consumption for mobile or a better resistance to noise.
>
> MPE-FEC simply combine datagrams interleaving and a Reed-Solomon
> code. It is
> designed in such a way that it will be transparent for a receiver not
> supporting MPE-FEC. Datagrams are encapsulated and sent as usual.
> Reed-Solomon parity bytes are transmitted on the same Pid but with a
> different section type , for ULE it migth be a different type.
>
> Your thoughts about that.
>
>
> Benoit Oger
> Thales Broadcast & Multimedia
>
>