directv satelite change?

[HoTat2]

If your DVB-S2 tuner has provisions for scrambling codes then I think you could find them without too much difficulty provided you have all other transponder info like symbol rate, FEC, etc. What would you hope to gain from locking on to an HD transponder?

Curious, but can you confirm the accuracy of these DVB-S2 "tuning parameters" mentioned in a patent submitted by the DIRECTV Group for a "Home Media Center" ("HMC", original concept for the Genie) at the time back in 2015?

Specifically, for DIRECTV's "A3 stream type" they listed ...

"Network ID"

"Frequency"

"Polarization"

"Packet ID" (PID) of which is 13 bits.

"Mode ID", which indicates either QPSK or 8-PSK modulation at 1/4, 1/2, 3/5, 2/3, 3/4, 4/5, 5/6, 6/7, 8/9 and 9/10 FEC code rates.

"Symbol Rate" either 20 or 30 MSymbols/s

"Roll-off factor", .20, .25, or .35

"Physical Layer Header Unique Word" (PLH_UW) which is 90 bits in length.

"Gold Sequence Scrambler code" which is 18 bits in length.

"Pilot Indicator" which is 1 bit.

Two pertinent technical details to this thread explaining some of the above ...

Regarding the "Physical Layer Header Unique Word" (PLH_UW) ...

First the "Physical Layer Header" (PLHEADER) is a 90 bit long header applied to each 64,800 bit "FEC Frame."

It's comprised of a 26 bit "Start Of Frame" (SOF) sequence fixed at 0x18D2E82. Followed by a unique 64 bit "Physical Layer Signal" code which can vary for different transport streams. The entire 90 bit Physical Layer Header is then XOR'd with the Physical Layer Header Unique Word.

Regarding the "Gold Sequence Scrambler" ...

It is an 18 bit long data scrambler to randomize the I-Q modulation phases for transmission of symbols in an FEC frame. The Physical Layer Header is not applied to the Gold Scrambler process.

Any or all of this sound correct from your knowledge?

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[Inclined Orbit]

You would not be the first to lock onto a DTV HD carrier, we've been doing it since they went on air. All your parameters look familiar but I can't post any specific parameters being used. Usually a test receiver only needs the frequency, mode, symbol rate and FEC to lock plus the two to three or maybe four digit scrambling code. Using the wrong roll off will usually work but it will be optimum with the correct one.

Curious, but can you confirm the accuracy of these DVB-S2 "tuning parameters" mentioned in a patent submitted by the DIRECTV Group for a "Home Media Center" ("HMC", original concept for the Genie) at the time back in 2015?

Specifically, for DIRECTV's "A3 stream type" they listed ...

"Network ID"

"Frequency"

"Polarization"

"Packet ID" (PID) of which is 13 bits.

"Mode ID", which indicates either QPSK or 8-PSK modulation at 1/4, 1/2, 3/5, 2/3, 3/4, 4/5, 5/6, 6/7, 8/9 and 9/10 FEC code rates.

"Symbol Rate" either 20 or 30 MSymbols/s

"Roll-off factor", .20, .25, or .35

"Physical Layer Header Unique Word" (PLH_UW) which is 90 bits in length.

"Gold Sequence Scrambler code" which is 18 bits in length.

"Pilot Indicator" which is 1 bit.

Two pertinent technical details to this thread explaining some of the above ...

Regarding the "Physical Layer Header Unique Word" (PLH_UW) ...

First the "Physical Layer Header" (PLHEADER) is a 90 bit long header applied to each 64,800 bit "FEC Frame."

It's comprised of a 26 bit "Start Of Frame" (SOF) sequence fixed at 0x18D2E82. Followed by a unique 64 bit "Physical Layer Signal" code which can vary for different transport streams. The entire 90 bit Physical Layer Header is then XOR'd with the Physical Layer Header Unique Word.

Regarding the "Gold Sequence Scrambler" ...

It is an 18 bit long data scrambler to randomize the I-Q modulation phases for transmission of symbols in an FEC frame. The Physical Layer Header is not applied to the Gold Scrambler process.

Any or all of this sound correct from your knowledge?

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[HoTat2]

You would not be the first to lock onto a DTV HD carrier, we've been doing it since they went on air. ....

Though ever since the AIM and its ability to see and lock onto the Ka-band/DVB-S2 signals, I've never well understood the continued need for the dither procedure on the Ku band to indirectly peak up the Ka for a Slimline dish.



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[Inclined Orbit]

There is a video out that explains how meters or spectrum analyzers might only be able to peak within about .5 degrees and the Slimline series should be peaked within about .1 degree due to its specs and other Ka satellites parked 2 degrees away. You can't get there by just going for the broad peak, you have to find equal points several dB down either side of peak then park in the middle. The incorrectly termed "dither" procedure gets you within that .1 degree.

Of course all the Slimline specs and procedures came out before the opposing 2 degree Ka slots were populated and maybe there have been some studies that show a little misalignment is ok based on those studies, but I'm not privy to any new information like that. In my book, if you're a professional installer you follow the procedure and do it right. Otherwise maybe you're better off working at the car wash, but certainly not as a valet parking attendant risking customers vehicles.

Though ever since the AIM and its ability to see and lock onto the Ka-band/DVB-S2 signals, I've never well understood the continued need for the dither procedure on the Ku band to indirectly peak up the Ka for a Slimline dish.



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[HoTat2]

There is a video out that explains how meters or spectrum analyzers might only be able to peak within about .5 degrees and the Slimline series should be peaked within about .1 degree due to its specs and other Ka satellites parked 2 degrees away. You can't get there by just going for the broad peak, you have to find equal points several dB down either side of peak then park in the middle. The incorrectly termed "dither" procedure gets you within that .1 degree.

Of course all the Slimline specs and procedures came out before the opposing 2 degree Ka slots were populated and maybe there have been some studies that show a little misalignment is ok based on those studies, but I'm not privy to any new information like that. In my book, if you're a professional installer you follow the procedure and do it right. Otherwise maybe you're better off working at the car wash, but certainly not as a valet parking attendant risking customers vehicles.

Ok, now I understand ...

You're saying that whether it's Ku or Ka, you really can't get much within +/- .5° of the actual peak regardless of what the meter says.

Which is irrelevant for the broad peaks on the Ku band and 9° slot separation. But not for the narrow peaks of the Ka that need to be within +/- .1°

And yes, I'm very familiar with the "Laser Don't Lie" YT video and the lovely "Veronica" at the end there.

(Hey, wonder if she still works at the CBC there ... ).

Funny, just out of general interest, carefully looking all over the satellite imagery of the CBC on Google maps, I can't really locate anywhere that dish testing and evaluation range was where the video was made.

Unless it was formally a part of where the recently installed solar panel farm is now ....

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[Inclined Orbit]

From my recollection, the Slimline barely, if at all, meets specs for 2 degree adjacent satellite spacing at Ka. If there were no adjacent satellites at Ka you probably could peak for maximum smoke similar to an 18" dish and lock it down and I didn't really see any difference in performance between a cheap peak and the dither method early on before the adjacent Ka slots were populated. There is only so much headroom built into the system and a few tenths of a degree misalignment can eat up headroom from adjacent Ka satellite interference. The DTV system works very well when everything is aligned and working properly and all those TV ads from cable companies pointing out rain and similar problems with satellite are partially blamed on installers that cheated or something that degraded in the customers system after the install. That's my opinion.

The +/- .5deg statements were for Ku pointing as Ka pointing was not a viable way to peak the dish and I don't remember how peaky Ka is with a meter or analyzer on the Slimline.

BTW its "Veronica" not Vanessa in the video and she is now a personal trainer for a large company in TX. She works out many hours a day and could probably break you into several pieces if you really pissed her off.

The engineering buildings and small dish farm where the video was made are long gone and would have been at the north west end of the current solar panel farm. At least that's what the current employees tell me about all this stuff.

Ok, now I understand ...

You're saying that whether it's Ku or Ka, you really can't get much within +/- .5° of the actual peak regardless of what the meter says.

Which is irrelevant for the broad peaks on the Ku band and 9° slot separation. But not for the narrow peaks of the Ka that need to be within +/- .1°

And yes, I'm very familiar with the "Laser Don't Lie" YT video and the lovely "Vanessa" at the end there.

(Hey, wonder if she still works at the CBC there ... ).

Funny, just out of general interest, carefully looking all over the satellite imagery of the CBC on Google maps, I can't really locate anywhere that dish testing and evaluation range was where the video was made.

Unless it was formally a part of where the recently installed solar panel farm is now ....

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[HoTat2]

Thanks ...

Corrected to "Veronica."

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[slice1900]

Re: 2 degree Ka spacing...

Consider that Directv licensed Ka from 101, claiming they would use it for backhaul but the sites it is capable of backhauling between make little sense (they don't even have an earth station in Kansas City to my knowledge) so I think at least part of the reason they got it was to allow them to cozy the 99 & 103 satellites a bit closer to 101 (i.e. 99.25 ish and 102.75 ish) to keep them a bit further away from the Ka licensees at 97 & 105.

 

[slice1900]

Curious, but can you confirm the accuracy of these DVB-S2 "tuning parameters" mentioned in a patent submitted by the DIRECTV Group for a "Home Media Center" ("HMC", original concept for the Genie) at the time back in 2015?

Specifically, for DIRECTV's "A3 stream type" they listed ...

"Network ID"

"Frequency"

"Polarization"

"Packet ID" (PID) of which is 13 bits.

"Mode ID", which indicates either QPSK or 8-PSK modulation at 1/4, 1/2, 3/5, 2/3, 3/4, 4/5, 5/6, 6/7, 8/9 and 9/10 FEC code rates.

"Symbol Rate" either 20 or 30 MSymbols/s

"Roll-off factor", .20, .25, or .35

"Physical Layer Header Unique Word" (PLH_UW) which is 90 bits in length.

"Gold Sequence Scrambler code" which is 18 bits in length.

"Pilot Indicator" which is 1 bit.

Two pertinent technical details to this thread explaining some of the above ...

Regarding the "Physical Layer Header Unique Word" (PLH_UW) ...

First the "Physical Layer Header" (PLHEADER) is a 90 bit long header applied to each 64,800 bit "FEC Frame."

It's comprised of a 26 bit "Start Of Frame" (SOF) sequence fixed at 0x18D2E82. Followed by a unique 64 bit "Physical Layer Signal" code which can vary for different transport streams. The entire 90 bit Physical Layer Header is then XOR'd with the Physical Layer Header Unique Word.

Regarding the "Gold Sequence Scrambler" ...

It is an 18 bit long data scrambler to randomize the I-Q modulation phases for transmission of symbols in an FEC frame. The Physical Layer Header is not applied to the Gold Scrambler process.

Any or all of this sound correct from your knowledge?

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All of that stuff is basically from the DVB-S2 spec. I can fill in a few blanks from what I know which is that their transponders always use a roll off of .20, a symbol rate of 30 Msymbols/sec (for Ka; for Ku it is 20 Msymbols/sec) and AFAIK they only ever use QPSK 2/3 for CONUS Ka transponders (as well as the one DVB-S2 / MPEG4 transponder on 119) though for spot beams they use various combinations depending on how much bandwidth they need to squeeze out of them.

 

[Inclined Orbit]

I think its common knowledge the Ka license at 101 is to hog the slot. There has been Ka activity there in the past.

Re: 2 degree Ka spacing...

Consider that Directv licensed Ka from 101, claiming they would use it for backhaul but the sites it is capable of backhauling between make little sense (they don't even have an earth station in Kansas City to my knowledge) so I think at least part of the reason they got it was to allow them to cozy the 99 & 103 satellites a bit closer to 101 (i.e. 99.25 ish and 102.75 ish) to keep them a bit further away from the Ka licensees at 97 & 105.

 

[Inclined Orbit]

Why would you say the spot beams use various combinations of parameters or different parameters than CONUS? Do you have information to support that?

All of that stuff is basically from the DVB-S2 spec. I can fill in a few blanks from what I know which is that their transponders always use a roll off of .20, a symbol rate of 30 Msymbols/sec (for Ka; for Ku it is 20 Msymbols/sec) and AFAIK they only ever use QPSK 2/3 for CONUS Ka transponders (as well as the one DVB-S2 / MPEG4 transponder on 119) though for spot beams they use various combinations depending on how much bandwidth they need to squeeze out of them.

 

[HoTat2]

Why would you say the spot beams use various combinations?

Yes they do, but not Ka CONUS which are always at a 2/3 FEC code rate ...

Just like here in the LA market (Market ID 624), the three local spotbeam tps. from the DIRECTV-12 satellite at 103W (Now renamed "T12" by AT&T, ... "yuck") TIDs 142, 144, and 145 (assigned tp. chs. 19, 21, and 22) streams are using 8-PSK with an FEC of 3/5.

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[Inclined Orbit]

I was referring to Ka.

Yes they do, but not Ka CONUS which are always at a 2/3 FEC code rate ...

Just like here in the LA market (Market ID 624), the three local spotbeam tps. from the DIRECTV-12 satellite at 103W (Now renamed "T12" by AT&T, ... "yuck") TIDs 142, 144, and 145 (assigned tp. chs. 19, 21, and 22) streams are using 8-PSK with an FEC of 3/5.

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[HoTat2]

I was referring to Ka.

So was I ...

Three of the local Ka-lo band spotbeam transponders on D12 (T12) at 103W supply most of the HD locals for the LA market.

Specifically their transponder IDs are 142, 144, and 145 which operate on Ka-lo tp. channels 19, 21, and 22 displayed on the 103(s) signal screen.

Tp. 19 is on spotbeam A1BB
Tps. 21 and 22 is on spotbeam A4BB which largely overlaps A1BB.

Does DIRECTV use different terminology?

As the above specification language is taken from the iamanedgecutter site forum based on their data captures of DIRECTV metadata and official FCC filings for their satellites.

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[HoTat2]

Well actually, to be more accurate ...

The "logical" TIDs on the T12 local spotbeam tps. for the LA market are 142, 144, and 145.

These numbers can be seen in the 90 hexadecimal character string in reply to running a "SHEF" query to a satellite receiver connected to the same home network from an a computer web-browser.

The "Physical" names are SP112, SP471, and SP472 taken from the FCC documents on the satellite.

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[Inclined Orbit]

looking over some paperwork, I don't see the same spotbeam terminology used by people who work on the uplink equipment.

So was I ...

Three of the local Ka-lo band spotbeam transponders on D12 (T12) at 103W supply most of the HD locals for the LA market.

Specifically their transponder IDs are 142, 144, and 145 which operate on Ka-lo tp. channels 19, 21, and 22 displayed on the 103(s) signal screen.

Tp. 19 is on spotbeam A1BB
Tps. 21 and 22 is on spotbeam A4BB which largely overlaps A1BB.

Does DIRECTV use different terminology?

As the above specification language is taken from the iamanedgecutter site forum based on their data captures of DIRECTV metadata and official FCC filings for their satellites.

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[HoTat2]

looking over some paperwork, I don't see the same spotbeam terminology used by people who work on the uplink equipment.

Any confidentiality prohibitions against sharing their terminology of the up/downlink beams and transponders IDs.

Would be interesting ...

As I said, we mostly only have access to DIRECTV's offical FCC filings of their satellites and earth stations. The various unencrypted metadata captures of their transmissions, and whatever technicians may mention on these forums.

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[Inclined Orbit]

Not a good idea. I have some documents with upwards of three different names or numbers for beams and transponders. The FCC might know it as one thing, station keeping as another and broadcast centers might call it something else.

Any confidentiality prohibitions against sharing their terminology of the up/downlink beams and transponders IDs.

Would be interesting ...

As I said, we mostly only have access to DIRECTV's offical FCC filings of their satellites and earth stations. The various unencrypted metadata captures of their transmissions, and whatever technicians may mention on these forums.

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[HoTat2]

Not a good idea. I have some documents with upwards of three different names or numbers for beams and transponders. The FCC might know it as one thing, station keeping as another and broadcast centers might call it something else.

Ok ...

Then using the terminology on the public record and from DIRECTV's unencrypted metadata.

Can you offer any corrections or suggestions for improvement to the most recent DIRECTV transponder data info. spreadsheets published on the iamanedgecutter site that we rely on?

Or does this appear good enough?

http://iamanedgecutter.com/attachment.php?attachmentid=2066&d=1528912498

Please take your time studying it ...

Thanks ...

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[Inclined Orbit]

Your link is for a Sky Mexico 79deg slot and that is after my time. I have all the Sky 58deg slot info but also have non disclosure agreements with them.

Ok ...

Then using the terminology on the public record and from DIRECTV's unencrypted metadata.

Can you offer any corrections or suggestions for improvement to the most recent DIRECTV transponder data info. spreadsheets published on the iamanedgecutter site that we rely on?

Or does this appear good enough?

http://iamanedgecutter.com/attachment.php?attachmentid=2066&d=1528912498

Please take your time studying it ...

Thanks ...

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