1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

How does Dish receive the channels?

Discussion in 'General DISH™ Discussion' started by Mike109, Nov 7, 2010.

  1. James Long

    James Long Ready for Uplink! Staff Member Super Moderator DBSTalk Club

    46,197
    1,075
    Apr 17, 2003
    Michiana
    No to mention the fiber backhauls from wherever DISH gets the signal to the correct uplink, uplink centers that would not exist if not for locals, etc. There is a lot of expense in carrying locals before paying the ransom, - uh - carriage fee.
     
  2. Mike109

    Mike109 Legend

    257
    0
    Jun 28, 2010
    How many versions of CBS for example do the Dish satellites carry? My Chicagoland CBS has the local news & commercials. And NY and other cities do the same. If Dish rebroadcasts all these locals does that mean there are multiples of the same CBS programs being beamed up & back that are the same except for the local news & commercials? I would think this would use a lot of bandwidth. Or how do they do it?
     
  3. James Long

    James Long Ready for Uplink! Staff Member Super Moderator DBSTalk Club

    46,197
    1,075
    Apr 17, 2003
    Michiana
    It does. That is why they use the spotbeams to "share" the bandwidth between different areas of the country. Your Chicago locals don't have far to go as the uplink is in Monee. My South Bend locals are also uplinked from there.
     
  4. whatchel1

    whatchel1 Hall Of Fame

    1,086
    0
    Jan 10, 2006
    There are 210 DMA's so most will have 1 of each of the big 4 stations. They carry all of the DMA's some are still SD. But they are supposed to be carrying all of them. So 210 x 4 = 840 give or take a few. They will be adding PBS across the country before long (they were supposed to do it by end of yr but isn't gonna happen). So it will then be 210 X 5 = 1050 roughly. Add a few CW's etc and it will take a huge amount of bandwidth. that's is exactly why they use as much as possible spotbeams.
     
  5. James Long

    James Long Ready for Uplink! Staff Member Super Moderator DBSTalk Club

    46,197
    1,075
    Apr 17, 2003
    Michiana
    Satellite carriers are not required to carry locals in all markets, although DISH has done so in order to regain the benefit of also being able to deliver distant stations to markets that are missing a network (and any other qualified customer).

    Satellite carriers are not required to carry HD locals in all markets, although if they carry any HD channel in a specific market they will have to carry all HD channels in that market by February 2013. It would be perfectly legal for DISH (and DirecTV) to stop adding HD markets and simply fill in the HD stations in markets already carried - leaving some markets with zero HD carriage.

    The accelerated schedule for PBS HD (50% of markets carried in HD having their PBS carried in HD by Dec 31st, 2010, 100% of markets carried in HD having their PBS carried in HD by Dec 31st, 2011) has apparently been avoided, however DISH does need to carry the PBS and other channels in each market carried in HD on the phase in schedule leading up to February 2013 (15% of markets carried in HD must have all of their HD channels now, 30% of markets carried in HD must have all of their HD channels Feb 2011, 60% of markets carried in HD must have all of their HD channels Feb 2012, 100% of markets carried in HD must have all of their HD channels Feb 2013). New HD markets added must immediately get their PBS HD. Markets not carried in HD do not have to have their PBS or any other HD signal carried.

    The law applies to local into local carriage ... delivery of national HD channels does not require the carriage of locals in HD. But once a satellite carrier decides to carry one local in a market the "carry one, carry all" provision kicks in and the thresholds above must be met including that market.
     
  6. Mike109

    Mike109 Legend

    257
    0
    Jun 28, 2010
    I understand the basic concept that spotbeams are aimed at & serve only a small area of the country. From what I've been reading, spot beams transmit different data signals using the same frequency. But don't they run out of bandwidth?

    How do they actually send a spotbeam to Chicago or NY? Are there literally a hundred little parabolic reflectors on the satellite?
     
  7. James Long

    James Long Ready for Uplink! Staff Member Super Moderator DBSTalk Club

    46,197
    1,075
    Apr 17, 2003
    Michiana
    Each transmitter on the satellite has it's own bandwidth ... the experts just have to design the satellites so they are aiming using the same frequencies at overlapping areas (unless that is desired).

    The tricky part is the uplink bandwidth. Satellite companies can only use the transponders that they hold a license for. E-12 at 61.5 was built as Rainbow 1 for a company with only 11 licensed transponders so to get the most out of it for spotbeam use they designed it for 14 uplink centers - most of them feeding downlinks back to the same area as the uplink - plus eight more downlink spots tied to one of the 14 uplinks. DISH's retired E-7 and E-8 satellites were designed for two uplink centers. The newest ones are designed for six (nine on Ciel-2 but the additional three would serve Canada).

    With six uplink centers DISH can feed 126 transponders at 119 or 192 transponders at 129, 72.7 or 77. They don't feed that many to any one satellite location but with six uplinks that would be the maximum. Some of those feeds would be used to feed ConUS transponders and the rest would feed spotbeams sharing the other transponders.

    Ciel-2 at 129 is a good example of a packed spot beam satellite. More information is available here:
    http://jameslong.name/e129.html

    I believe they have a couple of large reflectors with transponders located at specific points in front of it where the beam projected will reflect on a specific area of the country. It is similar to how the receive dish works where the center LNB is aimed at a different location than the LNBs offset to the side.

    They also manage to distort the ConUS signals to focus more power on Alaska and Hawaii than the ocean between them. Satellites are really tricky things!
     
  8. Mike109

    Mike109 Legend

    257
    0
    Jun 28, 2010
    Thank you everyone for all the information.
     
  9. Mike109

    Mike109 Legend

    257
    0
    Jun 28, 2010
    The January 2011 issue of Wired magazine has article on the building & launching of a communications satellite for television & the Internet. One photo shows the big dish reflectors. A couple of the dishes appear to have large dimples, probably a foot or two in diameter. Sort of looks like the playing surface of a musical steel drum. One dish looks like it has similar sized dark spots on it. Just a thought, I wonder if these dimples or spots are what are used for the spot beams.
     
  10. Jim5506

    Jim5506 Hall Of Fame

    3,687
    37
    Jun 7, 2004
    The dimples are hopefully optical illusions and the dark spots are probably shadows of the LNB unit.

    Spotbeams are only from the satellite down to a small area on the earth through a lens on the antenna on tha satellite and have no direct relation to any uplink satellite dishes.
     
  11. James Long

    James Long Ready for Uplink! Staff Member Super Moderator DBSTalk Club

    46,197
    1,075
    Apr 17, 2003
    Michiana
    I believe he was referring to the downlink dishes seen on satellites.
     
  12. Mike109

    Mike109 Legend

    257
    0
    Jun 28, 2010
    I have no idea which antennas on the satellite are used for uplink or downlink. But the one reflector clearly shows dark circles arranged in a pattern. This was a European satellite & I have no idea if they use spot beams.

    One of my previous questions was how the satellite sends spot beams. When I looked at a USA map it appeared there were quite a few areas served by spot beams. This made me wonder if a satellite actually has dozens of antennas, each one covering a spot. After looking at the magazine photo it made think that perhaps one large reflector might be divided into sections.
     
  13. albert71292

    albert71292 Mentor

    38
    0
    Aug 19, 2005
    I believe the same thing is happening here in West Monroe,LA. Recently the local NBC affiliate was off the air for a couple of days because of a transmitter failure. It was also off on Dish at the same time. The station website said it could be viewed on Comcast Cable during the outage however.
     
  14. ClassicRockFM

    ClassicRockFM Cool Member

    12
    0
    Dec 11, 2010
    Here in Mid-Michigan its the same thing too. Comcast apparently gets fiber from the local PBS station (WKAR), including the digital subchannels. WKAR OTA transmitter is off-air overnight through 7am, but their programming continues airing during those hours overnight on Comcast. Dish apparently gets the WKAR signal off air and the station is listed as "off the air" on the program guide during those hours.
     

Share This Page