Does FSS mean spot beam or CONUS?

[Toonces]

or is it unrelated to beam size?

What exactly is FSS in detail (I know it stands for "fixed satellite services") and how is it different than circular (right/left) polarity on DBS or linear (vert/horiz) on C/Ku band? I am assuming it is different than those two because it requires a different type LNB?

 

[BFG]

Hi Toonces welcome to Satellite Guys!

While I don't know the nitty gritty specifics about FSS, it is unrelated to CONUS and Spot Beam.

Basically FSS is a lower powered satellite then a DBS satellite, so it requires a larger dish to pull in a signal and a different kind of LNB then the DBS sats use.

 

[Toonces]

Hi Toonces welcome to Satellite Guys!

Thanks! Good to be here.

Basically FSS is a lower powered satellite then a DBS satellite, so it requires a larger dish to pull in a signal and a different kind of LNB then the DBS sats use.

I guess I was trying to figure out if I can get these FSS birds on my BUD. It is a 10-footer with C and KU LNBs on it.

 

[TuxCoder]

FSS is linear polarization, and what we often specifically mean when we just say 'Ku'. C band is also linear, but I'm not sure that's part of FSS. DBS is circular polarity, but is still part of Ku band. DBS is also allowed to (and does) transmit at higher power, so a smaller dish is needed than FSS.

 

[TuxCoder]

Thanks! Good to be here.

I guess I was trying to figure out if I can get these FSS birds on my BUD. It is a 10-footer with C and KU LNBs on it.

Yes, you're all set up (depending on the receiver(s) you have and the programming you need). In fact, for Ku/FSS all you need is a 30" or so dish. But as you probably already know, C band gets you even more stuff.

 

[larrystotler]

C-Band uses the 3-6Ghz band and can be analog or digital.
FSS is 11.7-12.2Ghz. You also have KuX, which is like 10.0-11.2Ghz, also part of the FSS band.
FSS uses vertical and horizontal polarization.
DBS is 12.2-12.7Ghz. Circular polarization.
Ka band is from 17-20 or 30 GHz.
FSS and DBS are both Ku band.


Basically, the higher the freq, the smaller the beam overall. This is why the DBS sats only need an 18 inch dish while your FSS needs a 30"+ dish.

Ka band will also use a 30 inch dish since it will pickup a larger spread of the freqs.

E*9 is a 140 watt sat, which is definately not low powered. Evidently, there can be some misconception about this(which I was also guilty of at one time).

 

[mike123abc]

In the US Ku is divided into 2 main bands and some aux bands. In general the Ku-DBS portion of the band has the satellites separated by 9 degrees. This is what allows the smaller dishes. The satellites are far enough apart that a small dish can see one satellite without picking up the neighboring satellites. The satellites in this band also tend to be more powerful, but that is not a requirement, and some in the Ku-FSS are more powerful than those in the Ku-DBS. Ku-DBS was specifically planned for small dish reception.

Ku-FSS band has satellites spaced 2 degrees apart. This is what requires a larger dish so you can pick out one satellite without receiving the adjacent satellites. If a Ku-FSS satellite did not have neighbors on each side an 18" dish could work with these satellites. These satellites tend to be lower power, but some (like E9 at 140 watts) are more powerful than some ku-DBS (like E1, E2, and E3).

Ka band requires the smallest dish to receive the signal because the frequency is so much higher. But, Ka band dishes are going to have to be larger because of rainfade. Ka is 10x or so more likely to have rainfade, so a larger dish is needed to combat this.

Spot beams can be used by any band (ku-DBS, Ku-FSS, Ka, etc) it is up to the satellite builder to use either one transmit antenna to cover the whole US or use a bunch of antennas, each covering a small portion of the US and allowing them to use the same frequency over and over in different parts of the US. In general spot beam satellites cost a lot more to build and launch, so they are just not as common.