Logo

Satellite Internet Forum.

Welcome, Guest. Please Login
Welcome to this satellite broadband discussion forum.  Wherever you are and whatever your problem we are here to help each other. Connecting to the internet via satellite is not always easy but is critically important to those in remote places or with poor terrestrial infrastructure.  Both service providers and customers are encouraged to contribute.  Click Register at the bottom if you want to join. Read the Forum rules.
      Satellite internet forum            Help            Search            Login          
Pages: 1

Tooway Ka-Sat downlink and uplink assignments

(Read 1159 times)
bgknudson1
Member
**
Offline



Posts: 1
Tooway Ka-Sat downlink and uplink assignments
Aug 31st, 2015 at 9:53pm
 
Within each  unique KA-SAT spot beam, how many downlink channels are there, and what are the associated  bandwidths.  In response, how many uplink frequencies can a Modem select from and what are the associated bandwidths?
Back to top
 
 
IP Logged
 
Admin1
YaBB Administrator
*****
Offline


Personal text from: Profile,
Options, Top line

Posts: 836
Re: Tooway Ka-Sat downlink and uplink assignments
Reply #1 - Sep 1st, 2015 at 11:17am
 
I can only give part of the answer.

Each of the 82 spot beams has 250 MHz bandwidth and I believe there are 3 carriers each occupying 65 MHz and one carrier occupying 50 MHz of allocated bandwidth. I would guess these carriers are 52 and 40 Msps 8PSK 5/6 with information bit rates of 130 and 100 Mbit/s giving a total of 490 Mbit/s per beam, shared amongst the number of customers per beam. These figures are 'clear sky'.  In rain the modulation type and FEC change to maintain service with lower information rates.

A typical customer, with a 500 MHz wide receiver, will see 4 high level wanted carriers on the wanted polarisation occupying half the rx cable bandwidth, plus possibly 4 lower level carriers from one adjacent beam. Using the wrong receive polarisation a customer might see 8 lower level carriers from two adjacent beams.

If anyone has spectrum analyser plots of what they can see it would be helpful to put them here. Send to me eric@satsig.net




Back to top
« Last Edit: Sep 1st, 2015 at 1:13pm by Admin1 »  
WWW  
IP Logged
 
Pages: 1