dtt switch off

big_moe

adrian weckler, journalist with the sunday business post.

techno "expert"

for ages he has been writing poorly researched and incorrect articles.

as somebody in the technology (home AV) business, I find it increasingly frustrating as I have a losing battle to fight to try explain to punters why "yer man in the paper" is wrong. just because its printed, doesnt make it true!!

the straw that broke was last sunday (may 18th) about how DTT will be crap.

here is the article,
http://archives.tcm.ie/businesspost/2008/05/18/story32892.asp

stupidest quote:
"Does digital tv mean better tv quality??

No, just switch between your analogue and digital and see for yourself, no difference"

[i dont have the article in front of me, so im paraphrasing]

tosser. how can nobody be monitoring what he saying??

/rant over

If he reads this forum; Adrian, i'd love to speak to you and see where you get your "facts" from.

adam

byte

Hm, not much of an article to be fair. An opinion piece is probably the best way of describing it. I get the feeling he's not looking forward to DTT! :pac:

Sam Russell

What a load of junk, his article has no merit whatsoever.

1. He does not understand 'compression' and what it achieves.
2. He does not understand 'digital' and how it improves transmission.
3. He does not understand the delivery system for television - satellite vs terrestial vs cable.
4. He does not understand why anyone needs a set top box, the tuner of the particular TV is old technology. A new V will have the correct tuner.
5. He does not understand much does he. And he writes for the Post?

big_moe

Sam Russell wrote: »

What a load of junk, his article has no merit whatsoever.

1. He does not understand 'compression' and what it achieves.
2. He does not understand 'digital' and how it improves transmission.
3. He does not understand the delivery system for television - satellite vs terrestial vs cable.
4. He does not understand why anyone needs a set top box, the tuner of the particular TV is old technology. A new V will have the correct tuner.
5. He does not understand much does he. And he writes for the Post?

THANK YOU!!!

I read most of his articles, and the majority of them are way off. He has a few bits of correct info (sometimes) but for the most part his articles are totally incorrect.

It's terrible because he is greatly misleading the general public. I'm not looking for perfection in anybody's articles, but errors of this magnitude are unacceptable.

He is either doing zero research, or else just researching in the wrong places. Or maybe he is just the face, and somebody else is feeding him this §hite. There was a thread in the Mac forum here a while back about the same stuff and he was way off about them as well (another subject which I am quite knowledgeable on) I don't know..

The reason I posted this is because it needs to be dealt with. I've overlooked it for a long time now but this is just ridiculous. A very credible paper like The Post shouldn't have crap like this printed in it.

Adam

Sam Russell

I have been into TV retailers looking for a TV with MPEG4 - none of the ones I talked to knew anything about the DTT trials, about the impending decision to go MPEG4, and even less about which TV has MPEG4 (none as far as I know).

The media does not cover this subject atall, even PC Live has had no coverage, and they pride themselves as being 'Irish Technology'.

RTE should be pushing this now, but they are not.

big_moe

there are still are few places that do know what they are talking about!

at the moment there is no word on a tv with mpeg4 built in, and the irish service hasnt been finalised. a very reputable source told me that they are having trouble deciding on the format to use for ppv, but mheg5 is looking to be the choice. when this is decided then we will see tvs with the right tuners built in. panasonic will defo have one as they are a partner of the dtt group in ireland.

adam

Sam Russell

Can the CI slot in my TV provide MPEG4 decoding? I've seen CI CAM cards available for this but do not know if they will work.

byte

Sam Russell wrote: »

Can the CI slot in my TV provide MPEG4 decoding? I've seen CI CAM cards available for this but do not know if they will work.

I believe there is a module that you can plug into the CI slot that will allow MPEG4 channels to work, though no HD channels.

maxg

Why should the software of a stb/lcd bring a CI modul into the game if a channel is flagged as not scrambled.
Btw all the newer sony lcd's have a mpeg4 decoder. X3000, X3500, W3000, W4000.

L1011

The Neotion units are mainly used in France where the MPEG4 channels are encrypted to begin with so I dunno if FTA channels will be sent to the CAS.

big_moe

maxg wrote: »

Btw all the newer sony lcd's have a mpeg4 decoder. X3000, X3500, W3000, W4000.

i was almost 100% sure they didnt. so.. i've double checked the specs and they dont. they all only have an mpeg2 decoder.

watty

The Neotion Module / CAM can do MPEG4 to MPEG2 (though not as good picture as a real MPEG4 direct decoder) and / or do CAM functions with a viewing card.

But a basic CAM on an MPEG4 enabled TV would be cheaper.

On the SD MPEG4 test channel and on my own test transmissions (don't ask) the Neotion + technisat DTT has slight artifacts not on the Lyngbox DTT MPEG4 reception.

The Neotion card does work with clear/FTA MPEG4 channels on an MPEG2 setbox or TV.

Only for 16:9 or HD is digital better than a good analogue signal. Digital is more about fitting more channels in the same spectrum at acceptable quality. It needs about 9Mbps MPEG2 or 4Mbps MPEG4 to be really better quality than Analogue. Typical broadcast bitrates for good channels are similar quality to good reception Analogue, but not Y/C or RGB studio feed analogue at 4:3. Since 16:9 is butchered and resampled for analogue transmission, Digital is generally better than Analogue for Widescreen content.

Because only about 70% of people (or less) with aerial have a good analogue signal, many people will either have no signal or better picture after Analogue switch off.

Cable analogue & MMDS analogue doesn't come close to quality even of lower bitrate Terrestrial /Satellite Digital channels.

Sam Russell

I think that Sony do not say if they have MPEG4 decoders, because it will affect sales of non MPEG4 sets. No mention of MPEG4 is made in their specs - and I do think some of their top models do have it.

Is the MPEG decoding done in software, and if so, could a firmware upgrade add MPEG4 decoding to existing sets?

I think that if a CI card is installed, the signal is passed through it for decoding or unscrambling. Little technical info is available on any of these products. I am not sure if it comercial secrets or to confuse/hoodwink the customer.

big_moe

watty wrote: »

The Neotion Module / CAM can do MPEG4 to MPEG2 (though not as good picture as a real MPEG4 direct decoder) and / or do CAM functions with a viewing card.

yes i am aware of those, its not like maxg said though. he said the newer ones have an mpeg4 decoder. if that was the case i'd thought they'd advertise that!

sam russell wrote:

i think that Sony do not say if they have MPEG4 decoders, because it will affect sales of non MPEG4 sets.

i doubt it. the X & W are the most expensive tvs they make. people arent going to spend an extra few hundred quid on them just to have an mpeg4 decoder. people that buy the X & W arent buying just for the mpeg4 side of things.

PauloMN

What a crap article. A little knowledge is a dangerous thing.

He is also completely confusing readers by mixing a discussion on the delivery platforms (analogue v digital) with content discussions.

L1011

Sam Russell wrote: »

Is the MPEG decoding done in software, and if so, could a firmware upgrade add MPEG4 decoding to existing sets?

Possibly. Unlikely.

maxg

big_moe wrote: »

i was almost 100% sure they didnt. so.. i've double checked the specs and they dont. they all only have an mpeg2 decoder.

You should check the specs at sony europe, the advertisements in central europe and the reports of owners in central europe.
Sony doesn't mention an hd tuner for dtt in UK/Ireland for that lcd's because the tuner is not dvb-t2 compatible and the planed standard is dvb-t2 for hd via freeview in the UK.

maxg

watty wrote: »

The Neotion Module / CAM can do MPEG4 to MPEG2 (though not as good picture as a real MPEG4 direct decoder) and / or do CAM functions with a viewing card.

But a basic CAM on an MPEG4 enabled TV would be cheaper.

On the SD MPEG4 test channel and on my own test transmissions (don't ask) the Neotion + technisat DTT has slight artifacts not on the Lyngbox DTT MPEG4 reception.

The Neotion card does work with clear/FTA MPEG4 channels on an MPEG2 setbox or TV.

The sd mpeg4 test channel is or better was marked as scrambled and got conax as scrambling system in the conditional access table.
A neotion viacess mpeg4 modul wouldn't had worked. Same for a channel which got no scrambled flag and no scrambling system attached in the CAT.


l

watty

Firmware updates don't add MPEG4. You need more powerfull HW/different chip set.

maxg, your last post is incoherent!

My neotion module has no CAM feature enabled. Only SD MPEG4 to MPEG2. It has a SIM sized card reader and ethernet port.

The Lyngbox does native MPEG4 SD and HD on DTT and Sat (DVB-s and DVb-s2)

maxg

It looks like you don't understand how a stb/lcd and CI modul are working together.
At startup the ci modul reports to the box which scrambling systems are supported and the firmware send only the streams of the channels to the ci modul which are marked scrambled and are marked to use a supported scrambling system.

dgently

Both Sony and Panasonic have announced TVs that are marketed as supporting Freeview HD which should, on paper, work here.

I do not know whether they feature a CI slot.

maxg

The dvb-t2 standard is not finalized till now and nobody can support anything which is not ready.
DVB-T2 is a new modulation method and there are plans in the uk to start HD via freeview with DVB-T2 at the end of 2009.
The new standard for HD in the UK is than mpeg4 transported via the modulation method DVB-T2.

pbirney

big_moe wrote: »

i was almost 100% sure they didnt. so.. i've double checked the specs and they dont. they all only have an mpeg2 decoder.

I can confirm that the Sony 46X3000 does decode MPEG4.

dgently

maxg wrote: »

The dvb-t2 standard is not finalized till now and nobody can support anything which is not ready.

You're right maxg, my post is misleading. While it's true that we've seen announcements of "HD Terrestrial" tvs, it is not yet clear that they will support the UK or Irish implementations, nor whether they could be upgraded via software to do so.

UK situation is nicely summarised here http://hdtvorg.co.uk/news/articles/2008041001.htm

watty

Most HD Terrestrial TVs are as misleading as a 32" 1366 x768 TV claiming to be HD.

many don't even do MPEG4. What they often mean is that it will receive Digital Terrestrial MPEG2 and that if you have an external HD set box with MPEG4 & HDMI, you can display a 1080i picture (though it may be resampling 1920x1080i down to 1366 x 768p)

Note that a 1920x1080p native resolution TV will give poorer broadcast reception (great for progressive DVDs) than a native 1920x1080i TV as ALL 1080 line broadcast are i not p because "p" needs twice the bandwidth. It's possible to perfectly convert 1920x1080 @ 24p to 1920x1080 @25i with no loss of sharpness. It's impossible to convert 25i to 25p without losing some sharpness on movement. Sadly many of the cheaper 1366x 768p sets don't de-interlace at all. They take half the lines which automatically gives 540p and rescale the 1920x540p to 1366x768p

A really top end farudja de-interlacing chip http://www.av-outlet.com/en-us/dept_335.html will only lose slight sharpness, and only on rapid motion, which LCDs & Plasmas blur anyway, no matter response time.

reslfj

dgently wrote: »

You're right maxg, my post is misleading. While it's true that we've seen announcements of "HD Terrestrial" tvs, it is not yet clear that they will support the UK or Irish implementations, nor whether they could be upgraded via software to do so.

UK situation is nicely summarised here http://hdtvorg.co.uk/news/articles/2008041001.htm

It it NOT nicely summarised - a large part of the text is WRONG!

"Consumers will need new equipment to pick up HD Freeview signals - namely set-top boxes which can decode the more advanced MPEG-4 codec, rather than the existing MPEG-2."

But in the UK, consumers will need a new box to receive DVB-T2 signals, too. The Ofcom plan is by regulation to force both changes ( MPEG-2->4 and DVB-T->T2) into the same box at the start of HD DTT transmissions i.e. at DSO ( 2009-2012).

This will save DTT viewers a very large sum.

"You may be aware that some TV's - namely the new Sony Bravia W4000 range of LCD TV's have an integrated HD TV Tuner and AVC-HD decoder which sits beside the DVB-T digital tuners. This eliminates the need for set-top box to access terrestrial HDTV programming."

All current TV's including all Sony models will need an external STB to receive UK HDTV via DTT. I France the Sony larger models will work, as France will for now transmits MPEG-4 encoded TV over DVB-T. Norway transmits MPEG-4 encoded SDTV over DVB-T.

"A word of caution however, while Ofcom has been suggesting ...
The problem is that UK H.264 HD looks likely to use the DVB-T2 standard, which is not compatible with the new tuners in Sony's W4000 series for example"

H.264 (= MPEG-4 part10) is a video compression standard and has nothing to do with the DVB-T2 digital transmission standard - DVB-T2 is 'radio-waves'.

So MPEG-4 wil not use DVB-T2, but MPEG-4 encoded video will be carried from the TV-tower to you aerial and TV set by DVB-T2 modulated radio-waves.

dgently wrote:

..it is not yet clear that they will support the UK .... implementation, nor whether they could be upgraded via software to do so.

It is 100% clear that there cannot be any 'software upgrade' to DVB-T2 .

The DVB-T2 reciever needs much more processing power and memory in the reciever 'chip' than the DVB-T standard. The new DVB-T2 chips will, however, be able to receive the old DVB-T signals.

Please note that some of the less expensive TV's - even HD Ready models - may have MPEG-4 decoders, but these can only decode SDTV signals. Check all specs. - get it in writing.


Lars

PS! I hope it is NOT "dtt switch off" , but ASO (analogue switch off) or DSO (digital switch over).

Sam Russell

Does anyone have a Neotion MPEG4 CI card I could try? I do not fancy paying out for one on the off chance it might work. The current two MPEG4 channels on test would either work (SD or HD) or not.

I have a Sony with a CI slot in Dublin.

reslfj

Sam Russell wrote: »

Does anyone have a Neotion MPEG4 CI card I could try? I do not fancy paying out for one on the off chance it might work. The current two MPEG4 channels on test would either work (SD or HD) or not.

I have a Sony with a CI slot in Dublin.

Neotion does NOT work with HD signals nor does your TV's MPEG-2 decompressor.

Lars

The Cush

The new Sony KDL-xxE4000 range probably includes an DVB-T MPEG-4 tuner but you would not know this by checking the specs on their Irish or UK websites.
According to komplett.ie and komplett.co.uk this range of TV's includes Digital TV Tuner: DVB-T, MPEG Profiles and Levels: MPEG4 AVC/H.264 HP@L4.
Checking out Sonys websites in Europe also indicates that this range of TVs include an MPEG-4 tuner.

Also the new Sony Bravia 26" LCD-TV KDL-26V4500 listed on komplett but not on Sony UK and Ireland websites yet, may also include an MPEG-4 tuner as it does in Germany and France for example.

But as Sony indicates on their website Technical Specifications - Please be aware that the features/specifications can differ from country to country.

big_moe wrote: »

at the moment there is no word on a tv with mpeg4 built in, and the irish service hasnt been finalised. a very reputable source told me that they are having trouble deciding on the format to use for ppv, but mheg5 is looking to be the choice. when this is decided then we will see tvs with the right tuners built in. panasonic will defo have one as they are a partner of the dtt group in ireland.
adam

According to Minimum Receiver Requirements for DTT in Ireland, (v1.0, 6 Feb 2008) "If the Receiver supports middleware, the ability to receive and output Data Broadcast Services presented in accordance with the "MHEG-5 UK Profile, version 1.06[17]" is a minimum requirement".

maxg

There is no "HD Tuner". Its like digital aerial.
The job of a tuner is to demodulate the signal and convert the signal to bits and bytes and do the error correction. Currently there are only tuners on the market which can handle dvb-t. The specs for DVB-T2 are not ready till now.
Mpeg decoding is the job of the mpeg decoder behind and the mpeg decoder can be on a extra chip or be part of the cpu. The newer sony X and W series have an mpeg2/mpeg4 decoder on board and an combined dvb-t/dvb-c/analogue tuner.

watty

Sam Russell wrote: »

Does anyone have a Neotion MPEG4 CI card I could try? I do not fancy paying out for one on the off chance it might work. The current two MPEG4 channels on test would either work (SD or HD) or not.

I have a Sony with a CI slot in Dublin.

It will never work for HD.
1) The bit rate is too high even for HD Sets
2) Non-HD sets can't take MPEG2 HD

The Neotion Pocket Duo is a poorer solution than a Set box for MPEG4:
1) Much poorer quality due to real time MPEG2 encoding
2) Poorer quality because signal is re-encoded
3) HD not possible
4) Substantial part of cost of a set box.

It is worth while if the CAM and a viewing card is used. Hence it is supplied by PayTV operators in France and you don't care about quality and don't ever want HD on DTT.

It was /is a stop gap solution till MPEG4 set boxes came out. The MPEG4 boxes now exist and getting cheaper.

Few TVs have HDD for PVR function. Push VOD and PVR is the future for flexible TV. TVs are becoming HiRes video monitors for the Digital Media Centre / PVR / Gaming system etc.

Go the set box route.

Sam Russell

My TV is a KDL40S300 which has a digital/analogue tuner that can decode DVB-T and DVB-C. It can receive the four FTA channels, and receive the sound from the HD channel. What I want to know is it possible to put in a CI card like the NEOTION one to decode MPEG4, and does anyone have one that I can try?
I think it should work, otherwise what is the CI slot for?

maxg

The ci slot is for paytv, ci modul and subscriber card.
The mpeg4 neotion modul give you additionally mpeg4 support if the provider use the same scrambling system and mpeg4.

watty

The Neotion pocket Duo should work for SD MPEG4, even FTA (in any TV's CI slot), even thought the CI is intended for a decryption system (CAM & viewing card) . But it will not work for HD. But I really think a set box is much better having compared both.

You really really don't want to get one Sam.

Sam Russell

I think STB solution is a bad one, a patch for inadequate TV's. I already have three zappers, I do not want a fourth. If the STB did everything, Sat FTA, DTV, PVR all in one box then maybe, but they currently do not.

I think 'HD Ready' on the TV is misleading, and should not be permitted. My set is not HD anything, unless I add something (expensive). My car is 'Turbo Ready' if I fit a turbo. But not if I do not.

I want my TV to do what it says it can do, but can't.

bk

Sam Russell wrote: »

I think STB solution is a bad one, a patch for inadequate TV's. I already have three zappers, I do not want a fourth.

Get yourself a logitech harmony remote. They are excellent.

reslfj

The Cush wrote: »

.-...this range of TV's includes Digital TV Tuner: DVB-T, MPEG Profiles and Levels: MPEG4 AVC/H.264 HP@L4.

This new TV line does NOT include a MPEG-4 tuner, but a DVB-T and/or DVB-C tuner.

But it does include a MPEG-4 HP L4 ( High Profile Level 4.0) decompressor. HP L4 is 720p (or 1080i) HDTV (they also support MP L3 SDTV and MPEG-2 SDTV)
http://pdf.crse.com/manuals/3298243111.pdf Page 33.

The line does not support MPEG-4 1080p (Full HD, HP L5 (or maybe L4.2/.3 ?), but 1080p is unlikely to be transmitted anytime soon, as it needs to much bandwidth and only makes a small difference for 55"+ displays.

Several of the current Sony models supports only MPEG-4 HP L3 SDTV via the DVB tuner and only HDTV via a HDMI connection.
Note the HD Ready mark has been and still is for the display and the HDMI interface ONLY.

The Cush wrote:

But as Sony indicates on their website Technical Specifications - Please be aware that the features/specifications can differ from country to country.

The spec. will be different for DTT in the UK - come November 2009 - where there must be a DVB-T2 tuner in front of the MPEG-4 decompressor in order to receive any HD from an aerial (DTT).
(Over time the current UK DTT SDTV will migrate to DVB-T2 and MPEG-4, too)

The new Sony models will not be able to use there integrated MPEG-4 decompressor in the UK - unless the DVB-T tuner chip is physically replaced by a DVB-T2 chip - (very unlikely to happen)

For any country that can wait with analogue switch off until late 2009/early 2010 - DVB-T2 and MPEG-4 HP L4 as minimum receiver spec., seems to be the ONLY smart choice for consumers.

The Cush wrote:

According to Minimum Receiver Requirements for DTT in Ireland, (v1.0, 6 Feb 2008) "If the Receiver supports middleware, the ability to receive and output Data Broadcast Services presented in accordance with the "MHEG-5 UK Profile, version 1.06[17]" is a minimum requirement".

This has nothing to do with MPEG-2 vs. 4 nor with DVB-T vs. T2.

Lars

watty

1080p versus 1080i gives NO EXTRA detail at ANY size, but uses twice the transmission bandwidth. It adds temporal information, it's important for usa 30fps as they have pul down artifact ftom 24 fps to 30i

1080p versus 1080i makes rapid movement better, the eye does not resolve rapid movement. It will eliminate single line flicker on CRT, but any decent LCD / Plasma doesn't have single line flicker as it uses Faruja or similar de-interlacer.

DVBs, DVBs2, DVBc, DVBt (DTT) and DVBt2 are all tuner/modulation technologies. You can't change by a SW upgrade. DVBs2 will also do DVBs and DVBt2 will also do DVBt

The DVBx2 versions give about 30% saving in spectrum or approx 30% more channels in same spectrum.

MPEG4 uses about 1/2 (or slightly better) the bitrate of MPEG2 compression for the video. SD or HD can be MPEG2 or MPEG4, though MPEG2 isn't used anymore for HD.

MHEG-5 is system for "middleware" or Interactivity or GUI. Sky uses "Open TV" (which of course is very proprietry) and some Operators use MHP.

MPEG2-TS is the method to multiplex Video (MPEG2 or MPEG4), Data (could be info for MHEG5 or Teletext, or PC download, anything) and Audio (MP2, AC3, AAC etc, not usually MP3, though possible) for one or multiple channels as a single serial data stream. This is what is received from the Tuner via DVB-s, DVB-c, DVB-t, DVB-h, DVB-S2 or DVB-t2 modulation.

DTT signal can be DVB-t AND DVB-h in the same multiplex, Hierarchical Modulation. This usually needs yet a different physical tuner to do both.

Some tuners use SDR / DSP zero IF techniques. Newer chip sets may indeed be able to add new tuner modes by firmware upgrade, but no current DVB-s tuner was upgradable to DVB-S2 by Firmware and is unlikely for current DVB-T designs (DVB-T2 is not even full formalised yet and may be a big mistake by Ofcom as it is not a huge saving).

reslfj

watty wrote: »

The DVBx2 versions give about 30% saving in spectrum or approx 30% more channels in same spectrum.

30% for DVB-S -> DVB-S2, but DVB-T2 will give much more. 45+ % for MFN like presently used in the UK and 65+% for larger SFN.




(Slides from DVB-T2 presentation by Alberto Morello, RAI April 3. 2008)

watty wrote:

MPEG4 uses about 1/2 (or slightly better) the bitrate of MPEG2 compression for the video. SD or HD can be MPEG2 or MPEG4, though MPEG2 isn't used anymore for HD

Real time MPEG-4 encoders cannot compress that much - more like 2/3 of MPEG-2.
( MPEG-2 encoded HD is still used in the USA - I think. )

watty wrote:

MPEG2-TS is the method to multiplex Video, Data etc.

Agree, but that name MPEG2-TS 'transport stream' ...
MPEG2-TS is an old and much misplaced name as it has nothing to do with MPEG-2/MPEG-4 video compression. The MPEG2 part is an early digital 'family name' much like the prefix DVB is today.

watty wrote:

DTT signal can be DVB-t AND DVB-h in the same multiplex, Hierarchical Modulation. This usually needs yet a different physical tuner to do both.

Do not count on Hierarchical Modulation in the future. DVB-H2 will be very different from DVB-H. Standards like MediaFLO and DVB-SH are much better than DVB-H.

watty wrote:

...but no current DVB-s tuner was upgradable to DVB-S2 by Firmware and is unlikely for current DVB-T designs (DVB-T2 is not even full formalised yet and may be a big mistake by Ofcom as it is not a huge saving).

DVB-T2 is final and has been for some time now, but it is only available to members of DVB.org - yet. The dvb.org members includes most or all of the important chip companies.

The benefit of DVB-T2 is much more than the 45-65% capacity increase. The DTG in the UK writes, that the most important feature of DVB-T2 is its ability to support much larger SFN. (DTG summit 2008).


Lars

watty

DVB-t and DVB-t2
Those aren't at same QAM and guard interval. I think the saving much less at same QAM. I'll bet on the real world saving as less than 45% and never near 65%. These things are always over hyped.

Qualcomm wants us to believe Mediaflo is better. Time will tell.

Very interesting

The leading makers of Multiplex /Re-encoding such as Scopus and Optibase etc all claim better than 50% real time for MPEG4

The US regards 480p as "HD". That is in MPEG2 (May be 840 approx x 480p rather than 720x 480p though)

MPEG-TS Transport stream is like saying VSAT Terminal (TS = Transport Stream. VSAT = Very Small Aperture Terminal)

reslfj

watty wrote: »

DVB-t and DVB-t2
Those aren't at same QAM and guard interval. I think the saving much less at same QAM. I'll bet on the real world saving as less than 45% and never near 65%. These things are always over hyped.

But it is the DVB-T2 equivalent modulation e.i. same signal robustness (signal/noise ratio) and have better impulse protection.
The guard interval is 100% the same in microseconds (224us) as 32k is used.

watty wrote:

Qualcomm wants us to believe Mediaflo is better. Time will tell.

MediaFLO is better than DVB-H - much better - but DVB-SH beats MediaFLO and expect DVB-H2 to perform even better.
But all of this are for mobile reception - DVB-T2 is for static reception.
The calculated performance of DVB-H, MediaFLO and DVB-SH has been verified by real measurements.

watty wrote:

The leading makers of Multiplex /Re-encoding such as Scopus and Optibase etc all claim better than 50% real time for MPEG4

But do they or do you and I have to watch the results ?
This may be true sometime in the future, but Freesat BBC-HD is encoded with 16 Mbps and France reports problems with HD and MPEG-4 at 10 Mbps for just the video.

http://www.dvb.org/news_events/dvbscene_magazine/DVB-SCENE25.pdf page 9.
"Video quality proved to be very

impressive, but some artefacts were
noticeable at a coding rate of 10 Mbps
(for video only) with actual MPEG-4 real
time encoders. Big improvements are

still expected."

Expected and much needed.

Lars

Before you write 'over hyped' take a look here: http://www.ebu.ch/en/union/news/2008/tcm_6-60107.php

watty

16Mbps HD is approx 3.2Mbps of SD at same quality.

10Mbps average will only be good for HD if peak rate can go to 18Mbps.

As a rule of thumb the peak needs to be about twice the average real time target. Hence statistical Mux and hope all the channels don't show the same football at same time


I forget that as you increase the number FFTs that the guard is improved. However my tests show that the phase distortion performance of amplifiers and mixers deterorates rapidly with increase of number of carriers per MHz (related to FFTs, 2K about 1,700 carriers and 8K about 6,900 carriers).

We won't really know how much advantage there is till real commercial receivers are deployed. Tests on MMDS type systems and CATV distribution show that even 2K OFDM can end up only supporting 1/3rd the bitrate of DVB-c after FEC.

I used to think OFDM was best thing since sliced bread, but only betweeen TX Aerial and RX aerial ( and for about 1.5Ghz and lower outdoors or up to 10Ghz indoors). As you increase number of carriers per MHz the electronics becomes a bigger problem.

reslfj

watty wrote: »

As a rule of thumb the peak needs to be about twice the average real time target. Hence statistical Mux and hope all the channels don't show the same football at same time

This is where the probability of all 3 HD channels in a DVB-T2 MUX will show the same football is much smaller than with 2 HD channels in a DVB-T MUX.

watty wrote:

I forget that as you increase the number FFTs that the guard is improved. However my tests show that the phase distortion performance of amplifiers and mixers deterorates rapidly with increase of number of carriers per MHz (related to FFTs, 2K about 1,700 carriers and 8K about 6,900 carriers).

The guard improvement alone is almost 18% better bitrate.

Sorry, bit when all of dvb.org has used two years and 10+ mill € (maybe even 10++ mill €) on the development of DVB-T2, I trust there simulations and tests more than I trust yours.

watty wrote:

I used to think OFDM was best thing since sliced bread, but only between TX Aerial and RX aerial . As you increase number of carriers per MHz the electronics becomes a bigger problem.

Note QAM256 CR3/5 has same net-bitrate as QAM64 CR4/5, but the T2-TM simulations apparently shows better noise performance for the higher QAM and the lower code-rate. The LDPC/BCH FEC is vastly superior to Vitabi/RS.
DVB-T2 is for TX antenna(s) to one RX aerial and you can be sure the electronics (one chip) will be able to perform. There are many modes that DVB-T2 can operate in. There are rumors that all DVB-T2 receivers will have 2 tuners as standard. This will enable 'deversity' receiption just by connecting an extra aerial.
The new dibcom.com DVB-SH chip has two tuners operating in 'diversity' mode. http://www1.dibcom.info/Images/Upload/pdf/CP/PR_DVB-SH_MWC_%20080204_UK.pdf


Lars

watty

My physical hardware is not as good as their simulations sadly. But I don't argue with them. I havn't got a DVB-T2 to test. I'm putting DVB-t through a transvertor. It behaves badly. DVB-s is fine.

I suspect many mast pre-amps / distribution amps won't be as good as their simulations.

It will be interesting in 2009 if UK does deploy it then to see how well it works.

I've had 30+ years of real life electronics not working as well as simulations.

Maybe this time someone has it right. Not long to wait to see.

I appreciate your input / posts.

Sligobuck

If it is any help i can recieve HD Ireland on Sony 46 X3500. Picture is excellent off indoor ariel in Shankill.

yellabelly

Why don't the BCI/RTE leave one multiplex as it is now with the main 4 channels mpeg2/FTA? There must be lots of Freeview TV set owners who don't want to have to buy another STB. Some will have a satellite STB (possibly just for FTA) picking up all the other channels they want. Also some people are happy with just the 4 Irish channels.

zilog_jones

They could do like what they did with the old 405-line system and continue broadcasting in areas where people were already receiving DVB-T from the trials or from the UK for a few years. However I don't know if there would be the bandwidth to do this and keep the same amount of channels in those regions as the rest of the country, and for how long will they need to do this?

IT Loser

byte wrote: »

Hm, not much of an article to be fair. An opinion piece is probably the best way of describing it. I get the feeling he's not looking forward to DTT! :pac:

Hardly surprising I suppose, most journos are just publicists for someone or other, and will shoot down the competition when they get a chance, or give their own guy a write up. Brendan O Connor and Paul Williams would be typical examples. In the world of Sports, Steve Bunce would be another example.

Sure RTE/The Irish Times have some retired Soldier dude working as their "Security Expert/Analyst"....:rolleyes: