Look at the top of the list- the column marked "501" is actually 501/508/510. They don't have 8PSK h/w.
Tech Chat Recap - November 14th, 2005
- Thread starter Tom Bombadil
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RandallA said:
(I don't mean to be rude, but...)
ALL HD IS IN 8PSK!
Looks like the smoke and mirrors is working.
Now, if they genuinely plan to switch EVERYTHING over to 8PSK, then this is an interesting, major announcement. And I'm glad to see they're thinking creatively and realistically. There's good news in here, but people don't seem to get it.
I don't think Voom and the HD-demo channels are 8PSK because when my 921 bit the dust I was still able to get a picture on those channels. Other HD and audio channels got sound but no picture. The info channels like 101, 103, 580 came in also.M Sparks said:
PS: When my 921 died, it had no operating system and no functions working except channel up/down so I'm fairly certain it wouldn't have been able to run the 8PSK turbo-code that dish downloads.
jergenf said:
(sigh) ALL HD IS 8PSK. ALL! ALL!(And so-obviously- is the 921.)
After reading the other thread, it appears the improvements will come from this "8PSK-TURBO" mode. None of the HD channels currently use this.
However, there still seem to be questions as to how important this is. Anything that frees up bandwidth is good, but people seem to be blowing this out of proportion.
(Or...if they are going to convert EVERYTHING to 8SPK, this is a much BIGGER announcement than people seem to think.)
Okay, all HD is in 8PSK.
Now, is there any difference between the 8PSK currently being used vs this "new" term 8PSK-Turbo?
If there is, then will E* realize some bandwidth savings by employing 8PSK-Turbo on their HD channels? Would this be 10%? 20%? 30%?
And, to be clear, are we in agreement that at present there is no reason for E* to implement MPEG-4 until decoder technology substantially improves? And if so, then it seems unlikely that there will be any advantages for having an MPEG-4 capable receiver in the next 12 months, right?
Another issue, will E* move SD channels to 8PSK-Turbo, knowing that would take a lot of time, and perhaps not being implemented until after MPEG-4 becomes a more efficient transport than 8PSK-Turbo?
Now, is there any difference between the 8PSK currently being used vs this "new" term 8PSK-Turbo?
If there is, then will E* realize some bandwidth savings by employing 8PSK-Turbo on their HD channels? Would this be 10%? 20%? 30%?
And, to be clear, are we in agreement that at present there is no reason for E* to implement MPEG-4 until decoder technology substantially improves? And if so, then it seems unlikely that there will be any advantages for having an MPEG-4 capable receiver in the next 12 months, right?
Another issue, will E* move SD channels to 8PSK-Turbo, knowing that would take a lot of time, and perhaps not being implemented until after MPEG-4 becomes a more efficient transport than 8PSK-Turbo?
Tom Bombadil said:
If they're already using 8PSK-Turbo.. which they might be.. since they can generally squeeze 3
onto one transponder without too much problem.. (I know I know it's not perfect) it should be relatively easy to shuttle SD through an encoder and send it out 8PSK-Turbo. I wouldn't think there's a lot of engineering needed there.. just some testing of the bitrates.
Purely my own speculation.
Sam
pdxsam said:
Technically they could do it. The problem is that there are a few million SD receivers that cannot decode 8PSK-Turbo.
E* could reclaim a lot of bandwidth by making this switch, however replacing millions of receivers is no simple deal. A lot of those people could not swap the receiver out themselves, so a tech would have to be sent out. The total cost would be quite high. E* has to weigh that cost vs the cost savings of gaining the bandwidth and the potential revenue gains from offering additional channels to attrace new subs.
I'm sure they've got people crunching numbers and engineers proposing solutions.
Tom Bombadil said:
Ahhhh I see... so even if they are 8PSK capable they may not be Turbo capable.. that does make the equation a lot different.
OMG Scott!!! Nooo please don't fuel the fire!
First off, Broadcom issued a press release almost two years ago about how Echostar is using their chip for 8psk turbo code. Here:
http://www.broadcom.com/press/release.php?id=473736
Link to the Broadcom website about the BCM4500:
http://www.broadcom.com/products/Satellite/HDTV-SDTV-Video,-Graphics-%26-Receiver-Chips/BCM4500
For technical details on QPSK and FEC, please read here:
http://www.coolstf.com/mpeg/index.html#srfec
The following was stolen from a very smart person on another forum:
"There are three different versions of 8PSK currently in use:
1. The first is the DSNG extension to DVB-S which uses Trellis encoded 8PSK (or 16QAM). I know of nothing sub $3K that'll get these signals and a bunch of them are scrambled distribution services (like ABC and CBC). I know of no single chip silicon that'll do this variety.
2. Dish Network is using Turbo-coded 8PSK and so was Voom until they gave up. There are also a few IP via satellite services using this and recently USDTV switched to this format too in C-Band. There are a couple chips including one that went into production from Broadcom that'll do this format.
3. DVB-S2. This is way cool and will eventually surplant all DVB-S - multiple streams within a stream, variable error correction rates and almost a 3dB gain just for switching to the QPSK version. Killer stuff. "
------------------------------------
So, to add my 2 cents (now dont go giving me nicknames or anything
)
1. All dish HD content is being sent on transponders using 8PSK with turbo code modulation. This includes VOOM, HD Pak, CBSs, the mpeg4 HD test content on 148, and the 4 West coast HD local channels (testing) on 129.
2. They are playing down the disappointment of MPEG4 buzz word by substituting another buzz word. 8PSK TURBO!
3. In the near future, the only thing we'll be seeing more of on 8psk transponders will be HD. Sure, they might have 12million or so 8psk equiped boxes deployed, but there are still a few million legacy and 501, 721s out there. They could try to do locals first, which would limit the impacted boxes to one geographic area.
4. A transponder is either 8PSK or QPSK, it cant be both. It can however contain both mpeg2 and mpeg4 content, SD and HD content. This also depends on how their multiplexers (the things that combine multiple video channels onto one transponder) work together. I know DTV had a problem with SD and HD on the same transponder.
5. If you want to know if your reciever can tune to 8PSK Turbo, goto the point dish screen, goto Satellite 110, and pick transponder 7. If you get a signal level, you're good to go. That TP happens to carry HDNet and HDN Movies. Again, there arent dish boxes out there that are 8psk, but not turbo. If you have 8psk ability, its good to go.
6. Remember, this chip is nothing new. It was first introduced in the 8psk module for the 6000. All HD content was converted over maybe 2 years ago? JohnH or Tony would know. When they converted, the model 5000 became useless for HD, as it could not decode 8PSK and had no upgrade slot. So, they've already made extinict one reciever.
Whew.
First off, Broadcom issued a press release almost two years ago about how Echostar is using their chip for 8psk turbo code. Here:
http://www.broadcom.com/press/release.php?id=473736
Link to the Broadcom website about the BCM4500:
http://www.broadcom.com/products/Satellite/HDTV-SDTV-Video,-Graphics-%26-Receiver-Chips/BCM4500
For technical details on QPSK and FEC, please read here:
http://www.coolstf.com/mpeg/index.html#srfec
The following was stolen from a very smart person on another forum:
"There are three different versions of 8PSK currently in use:
1. The first is the DSNG extension to DVB-S which uses Trellis encoded 8PSK (or 16QAM). I know of nothing sub $3K that'll get these signals and a bunch of them are scrambled distribution services (like ABC and CBC). I know of no single chip silicon that'll do this variety.
2. Dish Network is using Turbo-coded 8PSK and so was Voom until they gave up. There are also a few IP via satellite services using this and recently USDTV switched to this format too in C-Band. There are a couple chips including one that went into production from Broadcom that'll do this format.
3. DVB-S2. This is way cool and will eventually surplant all DVB-S - multiple streams within a stream, variable error correction rates and almost a 3dB gain just for switching to the QPSK version. Killer stuff. "
------------------------------------
So, to add my 2 cents (now dont go giving me nicknames or anything
)1. All dish HD content is being sent on transponders using 8PSK with turbo code modulation. This includes VOOM, HD Pak, CBSs, the mpeg4 HD test content on 148, and the 4 West coast HD local channels (testing) on 129.
2. They are playing down the disappointment of MPEG4 buzz word by substituting another buzz word. 8PSK TURBO!
3. In the near future, the only thing we'll be seeing more of on 8psk transponders will be HD. Sure, they might have 12million or so 8psk equiped boxes deployed, but there are still a few million legacy and 501, 721s out there. They could try to do locals first, which would limit the impacted boxes to one geographic area.
4. A transponder is either 8PSK or QPSK, it cant be both. It can however contain both mpeg2 and mpeg4 content, SD and HD content. This also depends on how their multiplexers (the things that combine multiple video channels onto one transponder) work together. I know DTV had a problem with SD and HD on the same transponder.
5. If you want to know if your reciever can tune to 8PSK Turbo, goto the point dish screen, goto Satellite 110, and pick transponder 7. If you get a signal level, you're good to go. That TP happens to carry HDNet and HDN Movies. Again, there arent dish boxes out there that are 8psk, but not turbo. If you have 8psk ability, its good to go.
6. Remember, this chip is nothing new. It was first introduced in the 8psk module for the 6000. All HD content was converted over maybe 2 years ago? JohnH or Tony would know. When they converted, the model 5000 became useless for HD, as it could not decode 8PSK and had no upgrade slot. So, they've already made extinict one reciever.
Whew.
Can I chime in and inquire...does all this 8PSK/Turbo talk mean we're going to see added HD channels soon or not? I personally only care about MPEG-4 if it means/carries the portent of more HD. Likewise any other standard/transmission talk. Was there anything explicit or implied in the actual chat about whether the rollout of new content was on track for first of the year as had been suggested?
8PSK tech details
So I was curious about what, exactly, 8PSK meant. So I went to Wikipedia (I know, I know...peer reviewed BS) and found this article. It made my head hurt with all the math, but I got the gist of it. If you're intersted in how PSK works and what it is, give it a read. Just be warned that you'll be reminded that you probably didn't pay enought attention in you differential math courses.
http://en.wikipedia.org/wiki/Phase-shift_keying
So I was curious about what, exactly, 8PSK meant. So I went to Wikipedia (I know, I know...peer reviewed BS) and found this article. It made my head hurt with all the math, but I got the gist of it. If you're intersted in how PSK works and what it is, give it a read. Just be warned that you'll be reminded that you probably didn't pay enought attention in you differential math courses.
http://en.wikipedia.org/wiki/Phase-shift_keying
BFG thanks for the knowledge, but still at least it has the capability. That makes me happy enough for future plans.
