22 replies to this topic

[mel816]

After first choosing DVB-T and then switching to ISDB-T, the Philippine government is now taking another look at the European technology with the emergence of DVB-T2 before settling on an "official" DTT standard for the Philippines:
Digital TV shift reviewed

Meanwhile the Japanese government has been lobbying Philippine regulators to go with ISDB-T:
Envoy urges adoption of digital TV standard

Edited by mel816, 21 May 2011 - 12:28 PM.

[alanh]

MEL816,
Interesting that there is a rethink. The DVB-T2 system is capable of carrying at least 30 % more data than the ISDB-T. It is not stated if they are proposing the ISDB using in Japan or the one used in South America. The South American version uses MPEG-4 compression and the Japanese version is MPEG-2 compression.

The USA influence in the Phillipines must have reduced because ATSC is not being considered at all.

Remember also that the Phillipines uses a 6 MHz wide RF channel like Japan and the Americas. The Phillipines also was an NTSC country so they also are using 60 Hz power.

So if they pick DVB-T2, there is a 6 MHz version, however what frame rate to be used will be interesting.

So the choice is between a much higher performing system compared to cheap loans for the broadcasters to use the ISDB.

Please post the eventual decision result.

AlanH

[bellotv]

alanh, on May 21 2011, 06:53 PM, said:

Remember also that the Phillipines uses a 6 MHz wide RF channel like Japan and the Americas. The Phillipines also was an NTSC country so they also are using 60 Hz power.

AlanH

AlanH

What is the relevance between  60 Hz NTSC frame rate and 60 Hz power ?

Surely this is purely coincidental as the two have absolutely nothing to do with each other.

You imply that their power system was chosen because of the type of TV system they had  

Bellotv

Edited by bellotv, 21 May 2011 - 08:23 PM.

[alanh]

belloTV,
When TV was first invented, the power mains was used to synchronise vertical scanning.  This was when electronics was very crude and very expensive. Later it could not be guaranteed than the power supplying the camera was the same as was being supplied to the receiver. So improved synchronisation circuits were developed. However any mains induced hum particularly in the receiver would cause the picture to roll and or flicker.

The reason this was the case was to reduce the visibility of hum in the video which would be nearly stationary if the power frequency and the frame or field rates are the same. If the other power frequency is used the hum causes a flicker at 10 Hz which is very obvious and annoying.

All of North America, large parts of Central and South America along with USA influenced Asian countries such as Japan, South Korea, Phillipines also use 60 Hz power mains. The rest of the world uses 50 Hz. Similarly the mains voltage in 60 Hz countries are generally 115 V (now) and all other countries 230 V (now) including Australia.

The NTSC system is only designed for 59.95 Hz field rate. There is no 50 field/s NTSC system.

All of the countries using NTSC have 60 Hz power except some areas of Japan which uses 50 Hz power @ 115 V. Only a few NTSC countries convert to ATSC digital with most of the others converting to the Japanese ISDB system and now a few of these are now considering DVB-T2 as described above.

Flicker is particularly a problem with lighting in the production studio or sporting arena if the mains frequency and the camera field frequency are not the same., The use of high frequency lighting overcomes this problem but is impractical in electronic news gathering.

Even now, if an outside broadcast which has to be powered from a generator is used, the generator motor must be controlled by a servo system to compare the mains frequency is synchronised to the TV system synchronising pulse generator. The keeps the field frequency and the produced power to be exactly the same frequency.

AlanH

[bellotv]

Thanks Alan

That all makes a lot of sense particularly with analog cameras and lighting flicker.

Apologize to MEL816 for going off topic but had to ask

Bellotv

[alanh]

Mel816
DVB Scene
I suspect that what happened in Africa is going on in Manilla at the moment!

BelloTV,
I can understand where you are coming from.

I understand that flat screen TVs store the electronic image and show each one multiple times.  The typical one is 8 times the frame rate which makes most TVs display at 200 full images a second. In ATSC and ISDB countries the display runs at 239.7602398 images/s. In cinema mode from Blu-ray discs there is 192 images/second.

The World Cup soccer refered to in the above link was all produced at 50 frame/s and South Africa has 50 Hz power. The signal was down coverted for transmission in DVB-T counries including Australia and in the ATSC/ISDB countries back to 29.97 frame/s. It may have been transmitted in the USA on 1280 x 720p/59.94 frame/s. In the case of the ATSC/ISDB countries the frame rate conversion makes the motion less smooth than in the rest of the world.


AlanH

[DrP]

The question of frame rate isn't particularly interesting at all, its pretty obvious what frame rate the Philipines will adopt for their digital system.  I'll make a bold prediction - it will be the same rate as their existing analogue system uses.  All digital telelvision standards currently defined support all popularly used frame / field rates so there are no particular hurdles to overcome WRT frame rate.

[reslfj]

alanh, on May 21 2011, 10:53 AM, said:

.....The DVB-T2 system is capable of carrying at least 30 % more data than the ISDB-T.

DVB-T to DVB-T2  in  MFN  mode ( UK mode ) in  6 MHz channels :   18  to   30.1 Mbit/sec  = +67%

DVB-T to DVB-T2  in SFN mode (GI=1/4 /89 km) in 6 MHz channels:  14.9  to 27.7 Mbit/sec =  +86%

A very significant increase and as the cost is unchanged  the DVB-T2 price/bit-rate is only around 60% og the DVB-T price (and ISDN-T price)

A higher capacity in a mux also enables better stat-muxing between more HD signals and thus a better quality encoding.

alanh, on May 21 2011, 10:53 AM, said:

It is not stated if they are proposing the ISDB using in Japan or the one used in South America. The South American version uses MPEG-4 compression and the Japanese version is MPEG-2 compression.

Any integration between the transmission of 'bits' and the semantics/encoding/interpretation of same bits, is a mistake*.  The new DVB-X2 standards has the option to use GSE - Generic Stream Encapsulation -  a low overhead framing that also enables IP framed data.  Current DTT usees the legacy  MPEG2-TS encapsulation, but even that enables both MPEG-2 and MPEG-4 to be carried - without changing standard.  

alanh, on May 21 2011, 10:53 AM, said:

The USA influence in the Phillipines must have reduced because ATSC is not being considered at all.
Remember also that the Phillipines uses a 6 MHz wide RF channel like Japan and the Americas. The Phillipines also was an NTSC country so they also are using 60 Hz power.
So if they pick DVB-T2, there is a 6 MHz version, however what frame rate to be used will be interesting.

Frame rate and AC frequency is not relevant to the transmission of 'bits' .

ISDB-T is no match for DVB-T2 - no match at all.   But ATSC is  such an impossible and stupid choice - by any standard!

Lars    


* In the IT industry  everything is done to move  into virtual resources - storage and calculations into the 'sky' - once we dialed via modem into a text-board, now everything is virtual and just an URL and a  click away - I have no knowledge about the path this post will  follow once i press 'Add Reply'.

Edited by reslfj, 22 May 2011 - 06:08 AM.

[alanh]

To keep this post for Mel816's topic on the Phillipines, I have moved the non Phillipines discussion to HD formats

AlanH

[DrP]

No alanh, you haven't moved anything.  All you've done is start another thread.  It is beyond your ability to 'move' anything on this forum.

[mel816]

alanh, on May 21 2011, 04:53 PM, said:

MEL816,
Interesting that there is a rethink. The DVB-T2 system is capable of carrying at least 30 % more data than the ISDB-T. It is not stated if they are proposing the ISDB using in Japan or the one used in South America. The South American version uses MPEG-4 compression and the Japanese version is MPEG-2 compression.

The USA influence in the Phillipines must have reduced because ATSC is not being considered at all.

Remember also that the Phillipines uses a 6 MHz wide RF channel like Japan and the Americas. The Phillipines also was an NTSC country so they also are using 60 Hz power.

So if they pick DVB-T2, there is a 6 MHz version, however what frame rate to be used will be interesting.

So the choice is between a much higher performing system compared to cheap loans for the broadcasters to use the ISDB.

Please post the eventual decision result.

AlanH

The Philippines currently uses NTSC-M for analogue TV so the frame rate will be 60i/30p along with a UHF-only band plan for either DTT standard.  As for ISDB-T, it's the South American variant with MPEG-4 video coding in addition to AAC audio.  My guess however is they'll stick with ISDB as Japan is the Philippines largest foreign investor/donor/creditor and the financing being offered by the Japanese seems too good to turn down

[alanh]

MEL.
I wouldn't say its a forgone conclusion, the ISDB must have used the same tactics in Africa. They cannot deny that the price of receivers is excessive due to the comparatively small marketm(See Brazil). See that the Africans are not going for HD but single transmitters carrying very large numbers of SD programs. The ISDB cannot do this due to its poor maximum data rate so for the same service more transmitters will be required. These countries have a lower income but are going to use DVB-T2.

You will just have to wait for a decision!

AlanH

[DrP]

ISDB does not have a particularly poor 'maximum' data rate.  In fact, its 'up there' with the rest of the digital television standards such as ATSC and DVB-t!  If ISDB has a poor 'maximum' then so do they.  

[mel816]

alanh, on May 23 2011, 12:37 PM, said:

MEL.
I wouldn't say its a forgone conclusion, the ISDB must have used the same tactics in Africa. They cannot deny that the price of receivers is excessive due to the comparatively small marketm(See Brazil). See that the Africans are not going for HD but single transmitters carrying very large numbers of SD programs. The ISDB cannot do this due to its poor maximum data rate so for the same service more transmitters will be required. These countries have a lower income but are going to use DVB-T2.

You will just have to wait for a decision!

AlanH

Actually the price of ISDB receivers/STB's is not "excessive" per se, they just seem expensive (based on prices in Brazil) because Brazil imposes (very) hefty taxes and duties on imported electronics.  Looking through OEM listings on Alibaba.com, ISDB HD boxes (with HDMI output) only cost around US$25-30 each wholesale from Chinese manufacturers (where most of the STB's of any DTV standard are made in anyway).

Unlike in Africa, broadcasters in the Philippines do intend to go HD and use their own transmitters/multiplexes (23Mbps max. each as per ISDB-T spec) rather than the shared-mux model used in Europe and Africa.  DVB-T2 might even have the same "problem" in the Philippines that ISDB had in Africa (this time in reverse) in that there are no existing 6Mhz deployments of DVB-T2 while ISDB-T has been up and running in other 6Mhz countries for several years now, which would make deployment costs  for DVB-T2 higher in the Philippines compared to ISDB-T.

[alanh]

Mel,
Check this large screen TV out. It receives DVB-T/T2, ATSC and ISDB-T
All standard STB

Brazil actually manufactures their own STB so no duty applies.

Unfortunately you cannot compare the cost of DVB-T2 TVs and PVRs and STB from the alibaba site. In addition this site does not contain the large manufacturers on any standard.

As I suggested above and resfi posted, you can use single transmitters for multiple programs on DVB-T2, where as in ISDB-t can only transmit only one HD signal at a time. So the Japanese have to offer broadcasters prices of less than half price for transmitters to make their old system pay.

DVB-T2 can quite easily work at 6 MHz, just like it is working at 7 and 8 MHz.

It is really upto the Phillipinos as to what they select.

AlanH

[mel816]

alanh, on May 23 2011, 11:11 PM, said:

As I suggested above and resfi posted, you can use single transmitters for multiple programs on DVB-T2, where as in ISDB-t can only transmit only one HD signal at a time. So the Japanese have to offer broadcasters prices of less than half price for transmitters to make their old system pay.

AlanH

Not quite true: using MPEG4 video coding ISDB-T can actually transmit two HD program streams simultaneously per RF channel or (depending on the broadcaster's choice) 6SD or 1HD+3SD programs.

[Smacca]

mel816, on May 24 2011, 12:03 PM, said:

Not quite true: using MPEG4 video coding ISDB-T can actually transmit two HD program streams simultaneously per RF channel or (depending on the broadcaster's choice) 6SD or 1HD+3SD programs.

A lot of what he says isn't true. But hey, he owns these forums, so there's not much we can do about it.

[alanh]

MEL,
What ever the capacity of ISDB MPEG4, DVB-T2 uses MPEG-4 as well. DVB-T2 has a much greater data rate so more services can be transmitted, particularly if they intend to transmit S3-D in the future.

AlanH

[DTV Pilipinas]

Hello to Australia's DTV forum. We're DTV Pilipinas, the only online organization of information about the DTV transition in the Philippines. We are into studies of the current digital TV setup of the country, since as of this writing, Philippines may be reviewing its choice of standard, as GMA Network, one of the Philippine major broadcaster, suggested DVB-T2 as the new standard for DTV. This is in fact, another delay for the transition of the country to DTV, since the country has decided, with the major TV networks, broadcast firms, and government institutions have unanimously decided ISDB-T as the sole DTT standard.

To look into the rules governing the Philippines' chosen standard, the technical working group decided to implement the harmonized ISDB-T and SBTVD standard, which uses MPEG-4/AVC for video, AAC for audio, BML datacast for middleware and capable of EWBS or Emergency Warning Broadcast System. Aside from that, 1seg or the mobile TV will also be implemented in the country, with MPEG-4/AVC and AAC as A/V standard.

Edited by DTV Pilipinas, 24 May 2011 - 09:33 PM.

[alanh]

DTV Pilipinas,
Thank you for posting the current situation. Do you know if the tactics used in DVB Scene are being used in the Philippines.

A quote from Lars "DVB-T to DVB-T2 in MFN mode ( UK mode ) in 6 MHz channels : 18 to 30.1 Mbit/sec = +67%

DVB-T to DVB-T2 in SFN mode (GI=1/4 /89 km) in 6 MHz channels: 14.9 to 27.7 Mbit/sec = +86%

A very significant increase and as the cost is unchanged the DVB-T2 price/bit-rate is only around 60% og the DVB-T price (and ISDN-T price)

A higher capacity in a mux also enables better stat-muxing between more HD signals and thus a better quality encoding."

This shows the attraction of DVB-T2 over all versions of ISDB.

DVB-T2 can give different characteristics to different streams so that you can have your DVB-Handheld characteristics included in the DVB-T2 data stream.

Handheld TV
Your regulators should also consider Digital Mobile Broadcasting (DMB) which is an extension of DAB+ digital radio. DMB is designed to transmit to portable receivers. The channels are 1.5 MHz wide instead of 6 MHz for TV. So you get 4 DMB channels in a TV channel which must be in the range 7 - 13. These DMB channels can also be used for DAB+ digital radio with around 9 broadcasters per transmitter.

using the vacated analog channels 2 - 4.

Channels 2 - 4 are unreliable in DTV transmissions regardless of the transmission standard.

Talking of digital radio, there is now DRM+ radiowhich uses analog TV channels 2 - 4 inclusive  when they are switched off.
There is a new HF DRM transitter in Malaysia, which should be easily receivable in the Phillipines. No fading and distortion.

Alanh

[SDL]

super, will they update Wowowee

[mel816]

Looks like they're sticking with ISDB-T:

Philippine regulator sticks by ISDB-T adoption

[alanh]

The latest news

AlanH