I am Talking in general. And if they swapped places with someone else for who knows what reason then right there you have an example of someone moving up.
Just a hunch based on the appearance that the launch dates were typically later than originally announced in presentations and/or initially scheduled (as reported by anik).
They're not showing a clear launch order for a number of reasons, probably, uncertainty about readiness of several of the payloads being chief among them.
Looking back to when DIRECTV 14 first got specific on salo's schedule (August 9, 2013) it was windowed for January 15 through March 1st. It was given a 45 day window ahead of one of the satellites (ABS 2) that launched Thursday. Prior to that it had been early 2014 (as was Athena-Fidus that launched Thursday as well).
Now it is vying for a spot in the Summer?
I say this without dragging in justification from oblique references to the early US space exploration program nor other largely unrelated examples that didn't prove quicker than four weeks.
For a brief break from the guesswork as to when D14 will finally launch, I have a question for the satellite experts out there.
Looking at a beam contour map for Directv's CONUS satellites, the highest signal power is provided in Florida, a bit less in the SE, a bit less in the midwest, and the least in the west. The reason is obvious, the more likely a particular area is to be affected by rain fade, the more power that is presented.
How easily/quickly can that be changed? If Directv had minute by minute information about where storms were, either from weather radar or updates on signal quality gathered from the millions of internet connected receivers around the country, could Directv command its satellites to alter their signal contour every few minutes to deliver more signal power to areas that need it? Following the storm's path and slightly in advance of where it is moving with signal power up to the maximum allowed. Or is making these changes a wildly difficult calculation that takes a great deal of planning and testing, making the type of automated signal contour changes I'm suggesting utterly impossible with current technology/procedures?
Obviously for the biggest storms even the maximum power the FCC allows wouldn't be enough, and there are potential objections to how easy it would be to obtain the data about where the power needs to be increased. Ignore those for the moment - they don't matter unless it is possible to change the CONUS beam contours on a nearly real time basis.
I'm pretty sure they can adjust the HD spot beam power levels (even those not on the SW sats). I say this because I have seen bluebird weather spot beam strength of less than 100 on my SS screens and I had a solid 100 this weekend during a pretty good snow shower. I'm sure they adjust those because those channels are probably the most frequently watched among subscribers. They don't want extra phone calls.
Yeah, possibly SB power level control to the same degree for all of one area may be adjusted this way;
But there is no practical way to reform a CONUS beam under some type of adaptive power control to vary levels to some regions and not others that I can see. Perhaps with some phased array antenna systems like on the Spaceways you could do something like this as P. Smith suggests. I don't know.
I mean, for CONUS beams the DVB-S2 standard used by DIRECTV's Ka band signals does have options for things like "Variable Coding and Modulation" (VCM) and "Adaptive Coding and Modulation" (ACM) systems on a packet by packet basis which can vary the signal link robustness of individual packet sub-streams within an aggregate transport stream multiplex to different downlink recipients of those sub-streams to compensate for atmospheric conditions.
But this won't work for broadcast applications of the standard over CONUS beams at least since all recipient subscribers may use all the same packet sub-streams.
Interactive IP type applications can use this type of system, but not broadcast ones and thus use the "Constant Coding and Modulation" (CCM) provision of the standard.
Yeah, possibly SB power level control to the same degree for all of one area may be adjusted this way;
But there is no practical way to reform a CONUS beam under some type of adaptive power control to vary levels to some regions and not others that I can see. Perhaps with some phased array antenna systems like on the Spaceways you could do something like this as P. Smith suggests. I don't know.
I mean, for CONUS beams the DVB-S2 standard used by DIRECTV's Ka band signals does have options for things like "Variable Coding and Modulation" (VCM) and "Adaptive Coding and Modulation" (ACM) systems on a packet by packet basis which can vary the signal link robustness of individual packet sub-streams within an aggregate transport stream multiplex to different downlink recipients of those sub-streams to compensate for atmospheric conditions.
But this won't work for broadcast applications of the standard over CONUS beams at least since all recipient subscribers may use all the same packet sub-streams.
Interactive IP type applications can use this type of system, but not broadcast ones and thus use the "Constant Coding and Modulation" (CCM) provision of the standard.
DTV does not use VCM/ACM for Ka feeds, they do changing FEC sometimes, but it's very rare, perhaps for very bad seasons. And modulation type: QPSK <-> 8PSK changes happened a few times. Perhaps Gary could step up with digging in his historical data.
OK thanks for the info guys. I wasn't sure how easily or even if the beam could be changed, and it sounds like what I'm hearing is that it is pretty much fixed at launch.
I would be curious to know whether they vary the power level for spot beams if there is weather in the area as Go Beavs suggests. Assuming it is bumped up to the maximum, comparing when signal is lost between the local SB and CONUS would tell how much (or how little) this would benefit even if it had been possible to do for CONUS.
What is the maximum power Directv is allowed to use? I checked the beam footprint library and my SB from D12 gives me 59.5 dbw, and D12 CONUS gives me 54.3 dbw. Despite that difference, I see the same signal quality reported - the extra 5.2 dbw must not actually increase my SNR by anything like 5.2 db. Go Beavs reports seeing 100 on his local SB at times, but apparently I'd need to have the power cranked even higher to reach that level. On the other hand, maybe 59.5 dbw is the highest they ever use, but they're providing me less power right now - comparable to the 54.3 dbw I get from the CONUS beam?
It would be interesting to track my signal for the locals tpn this spring/summer when there's a big storm in my SB footprint that isn't affecting me, to see if they do crank up the power, and then see if there's much difference in the amount/rate of signal drop between my locals tpn and a CONUS tpn when a storm approaches.
..
It would be interesting to track my signal for the locals tpn this spring/summer when there's a big storm in my SB footprint that isn't affecting me, to see if they do crank up the power, and then see if there's much difference in the amount/rate of signal drop between my locals tpn and a CONUS tpn when a storm approaches.
DTV does not use VCM/ACM for Ka feeds, they do changing FEC sometimes, but it's very rare, perhaps for very bad seasons. And modulation type: QPSK <-> 8PSK changes happened a few times.
Have they ever done that on the fly? Or just on unused transponders or adjustments done in the middle of the night when programming can be interrupted?
When I was troubleshooting something odd I noticed a few months ago I wrote a simple script that runs on my wireless router and queries one or more receivers for their current signal strength and logs the reported SS to a file with one update per second. If I had this running as a storm approached and one receiver was tuned to a LiL and another tuned to a CONUS channel on 103ca, I'd get a direct comparison between the two. If my signal suddenly jumped up to 100 with a storm in the area that wasn't affecting me, it would indicate they cranked up the power.
And yes, I realize the number is a measure of CNR/SNR. Its too bad there isn't a way for me to get the actual CNR, but your findings indicate a fairly linear relationship up until the mid 90s where the curve flattens quite a bit and several db of CNR seem to be required to bump from 95 to 100.
Have they ever done that on the fly? Or just on unused transponders or adjustments done in the middle of the night when programming can be interrupted?
unknown to me, as the changes are rare and samples taken once in a week
actually it could be automated (as done for DVB-S NIT monitoring), just need special parsing, SI tables are different in APG universe.
On today's financial call White said that the next US satellite goes up later this year, he thought in the fall. If it's going to take that long looks like not a bunch of new HD until 2015, bummer.
Looking at Dish's quartly results I noticed this one line:
DirecTV has obtained FCC authority to provide service to the United States from a Canadian DBS orbital slot, and EchoStar has obtained authority to provide service to the United States from both a Mexican and a Canadian DBS orbital slot.
Yes, it is the FSS frequencies immediately below (and at lower power than) DBS band.
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