Question in Regards to Spot Beams

[Chasjonk]

Can someone explain to me in laymans terms as to what must be done/accomplished to place a signal (such as the local channels) which at the moment on the 121 satellite are in CONUS format over to a spot beam on 121?

Also, any idea as to whether the locals on 121 because of the type of satellite it is (I understand that it is not the same type as say 110 or 119.... is that correct?, I've beleive I've seen 121 called a FSS) will be kept CONUS or eventually be set up on a spot beam?

 

[James Long]

Can someone explain to me in laymans terms as to what must be done/accomplished to place a signal (such as the local channels) which at the moment on the 121 satellite are in CONUS format over to a spot beam on 121?

First you need to have a spot beam satellite in place at that location. These things are designed on the ground with special antennas. One cannot just convert CONUS to spotbeam unless the design was there in the first place.

Assuming the satellite was designed for spot beams, it is a matter of moving the channels off the CONUS transponder and turning on the transponder on the beam you wish to use. I don't believe 121 was designed for spots.

Also, any idea as to whether the locals on 121 because of the type of satellite it is (I understand that it is not the same type as say 110 or 119.... is that correct?, I've beleive I've seen 121 called a FSS) will be kept CONUS or eventually be set up on a spot beam?

FSS is fixed satellite service, which is a lower powered (hence bigger receive dish) satellite in a different part of the Ku band. DBS is direct broadcast satellite, the higher power service seen at 61.5º, 101º, 110º, 119º, 148º, and 157º (plus additional slots).

There is nothing preventing the launch of a spotbeam FSS satellite that I know of. But I don't believe that E*9 at 121º has that capability, and it being a new bird it won't be replaced soon. (It won't be moved either, as part of that satellite is owned by another company. E* can't bounce it around as much as they have their other satellites.)

JL

 

[mike123abc]

The KU band of frequencies is divided into two parts, KU-FSS and KU-DBS. KU-FSS has satellites spaced 2 degrees apart and tend to be lower powered. The KU-DBS has satellites spaced at least 9 degrees apart and has higher power satellites.

The farther spacing and higher power allows a small dish to be used on KU-DBS. It takes a larger dish to focus in on an individual satellite in the closely spaced Ku-FSS band.

Now it is quite possible to put a spot beam satellite up that uses the KU-FSS frequencies. But, there is a ton of excess capacity in KU-FSS at this time, and a shortage of KU-DBS so spots to conserve KU-DBS makes sense at this time (5 KU-DBS slots vs 43 KU-FSS slots in the same space 61.5-148). Dish has been able to secure a couple of KU-FSS satellite slots/frequencies on the cheap (121 they own and 105 they lease). If they decided they wanted more they could probably pick up some more slots cheap.

A spot beam satellite is very expensive since it has a bunch of individual antennas on it and has to route all the signals to the right transponders on the right antennas. It also needs a lot more power (larger satellite, more solar cells, etc) to power all the spots, plus you need more uplink sites. For Ku-FSS it is just cheaper to get another slot.

 

[Stargazer]

It may be cheaper for Ku-FSS to not have spot beams but more expnensive by having to provide a SuperDish to all of the subscribers. It costs Dish one way or another but perhaps it is still cheaper to provide each customer with a SuperDish instead of having a spotbeam seeing that the markets provided at 105 and 121 are for a lot less subscribers than those that use spotbeams.