Simon, I might be wrong, but I'm sure that when you put in the parameters that are being used in the UK for DVB-T2 you get 30Mbps of post-error corrected data. It's quite possible that they have changed the parameters to provide 36Mbps, but my understanding was that 30Mbps is what you will get to get the "correct" 98.5% coverage.
I'm quite happy to be wrong about this, but I would like more proof than Wikipedia... It my experience that people talk up bitrates in the same way that they do hard drive sizes. Being an old hand in broadcast data transmission, I always use 2^10 for my "k" and 2^20 for my "M" and so on. Other people use 10^3 and 10^6 and this effects the result... 2009/9/18 Simon Thompson <st...@zepler.net> > Last time I checked the Blue book it didn't mention bitrates: > http://www.dvb.org/technology/standards/a122r1.tm3980r7.DVB-T2.pdf > > And the last time I saw the chairman of the DVB-T2 technical module > speaking he mentioned 36 Mbps: > > > > 2009/9/18 Brian Butterworth <briant...@freeview.tv> > >> Wikipedia is wrong (that's a suprise). The carrying capacity is 30Mbps, >> according to the specification. >> >> 2009/9/18 Simon Thompson <st...@zepler.net> >> >> 30 Mbps is a bit of a low estimate for T2. >>> >>> Wikipedia suggests at least 35. >>> >>> 2009/9/18 Brian Butterworth <briant...@freeview.tv> >>> >>> Briefly, DVB-T2 uses MPEG4 delivered in a 30Mbps (compare 18Mbps and >>>> 24Mps) multiplex using 256QAM (compared with 16QAM and 64QAM) with LDPC/BCH >>>> error correction (not FEC) and 32k carriers (compare 2k and 8k). >>>> http://www.ukfree.tv/fullstory.php?storyid=1107051377 >>>> >>>> Basically, this is not a software upgrade! >>>> >>>> 2009/9/17 Brendan Quinn <brendan.qu...@bbc.co.uk> >>>> >>>> Alan wrote: >>>>> > I assume my topfield HD will be out of date with these proposed >>>>> > changes? >>>>> >>>>> Ant replied: >>>>> > You'll need to retune, but the services you currently get on Freeview >>>>> > should still be available. Think of Freeview + as an optional >>>>> > upgrade. >>>>> >>>>> To which Alun wrote: >>>>> > I meant in terms of the HD element if they are changing the spec? If >>>>> there is a >>>>> > decryption requirement I doubt the Topfield will have it? >>>>> >>>>> I would say you're right, your box wont' receive HD freeview signals. >>>>> But that's not (only) because of any encryption, it's because the spec >>>>> for encoding HD over freeview [1] was only agreed last week and the >>>>> first box was announced five days ago, to be released "in the first >>>>> half >>>>> of 2010": >>>>> >>>>> >>>>> http://www.broadbandtvnews.com/2009/09/12/pace-unveils-dvb-t2-freeview-h >>>>> d-box/<http://www.broadbandtvnews.com/2009/09/12/pace-unveils-dvb-t2-freeview-h%0Ad-box/> >>>>> >>>>> I guess you have this box [2]: >>>>> >>>>> >>>>> http://www.topfield.co.uk/index.php?option=com_content&view=article&id=1 >>>>> 0&catid=2&Itemid=3<http://www.topfield.co.uk/index.php?option=com_content&view=article&id=1%0A0&catid=2&Itemid=3> >>>>> >>>>> It uses "HDMI upscaling" to work with your HD TV. But it's not actually >>>>> processing the real freeview HD signal and never can -- your box needs >>>>> different chips to be able to do that. So to actually see Freeview HD >>>>> in >>>>> HD, you will need to buy a new box :-( >>>>> >>>>> HTH, >>>>> >>>>> Brendan. >>>>> [1] known as DVB-T2. The DVB are the standards committee for most TV >>>>> standards in Europe, India, Australia etc. The BBC is a member. DVB-T >>>>> was the standard for regular freeview, so DVB-T2 is the standard for >>>>> next-gen freeview: the "T" is for terrestrial. You can guess that DVB-C >>>>> is for cable and DVB-S is for satellite... They also have C2 and S2 >>>>> standards for HD over those platforms. >>>>> [2] URL edited for brevity -- yes it was much longer than that before >>>>> -- >>>>> but it seems to work... >>>>> >>>>> - >>>>> Sent via the backstage.bbc.co.uk discussion group. To unsubscribe, >>>>> please visit >>>>> http://backstage.bbc.co.uk/archives/2005/01/mailing_list.html. >>>>> Unofficial list archive: >>>>> http://www.mail-archive.com/backstage@lists.bbc.co.uk/ >>>>> >>>> >>>> >>>> >>>> -- >>>> >>>> Brian Butterworth >>>> >>>> follow me on twitter: http://twitter.com/briantist >>>> web: http://www.ukfree.tv - independent digital television and >>>> switchover advice, since 2002 >>>> >>> >>> >>> >>> -- >>> Simon Thompson >>> GMAIL Account >>> >> >> >> >> -- >> >> Brian Butterworth >> >> follow me on twitter: http://twitter.com/briantist >> web: http://www.ukfree.tv - independent digital television and switchover >> advice, since 2002 >> > > > > -- > Simon Thompson > GMAIL Account > -- Brian Butterworth follow me on twitter: http://twitter.com/briantist web: http://www.ukfree.tv - independent digital television and switchover advice, since 2002
