Satellite Internet

Satellite Internet Forum.

Welcome, Guest.
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. If you are showing as 'Guest', please register at the bottom of the forum home page if you wish to contribute or ask question. May 2018: GDPR: Updates to Privacy and Cookies policies: As you may know, a new EU data protection law called GDPR will apply from Friday 25th May 2018. As part of satsig's commitment to protecting the privacy of site visitors and forum members, I have therefore updated the Privacy and Cookie policies. There are now links leading to these policies: Disclaimer, Terms of Use and Privacy, Forum User Agreement, Forum Rules and Cookies at the bottom of the home page and all forum pages. Read the Forum rules.
      Satellite internet forum          
Pages: 1

Formulas use in Satcom

(Read 2503 times)
Ex Member
Ex Member


Apr 8th, 2012 at 4:06pm  
Dear Mr.Eric

Can you provide me all the formulas use in satcom like bandwidth calculation, center frequency , symbol rate , occupied bandwidth for SCPC and as well as in DVB-S2 , It will be nice if you help me in this , my email id is leoboy89@gmail.com

Best Regards,
Back to top
 
 
IP Logged
 
Eric Johnston
Senior Member
***
Offline


Personal text from Profile,
Options, Top line

Posts: 2108
Reply #1 - Apr 8th, 2012 at 7:18pm  
As a baseline I suggest:
The occupied bandwidth = 1.19 to 1.2 x symbol rate.
The allocated bandwidth = 1.35 to 1.4 x symbol rate.

Allocated bandwidth is the amount of bandwidth you need to rent from the satellite transponder.  The satellite owner will decide, based on information about your carrier (symbol rate, power spectral density, filtering, frequency stability) so that you do not suffer unacceptable interference into your carrier from others or for you to cause unacceptable interference to others.  

If you have multiple adjacent carriers then, with agreement of the NOC, you can decide for yourself the spacing between your carriers.  If you move the carriers closer, your adjacent channel interference increases.

The shape of a DVB carrier is shown here:
http://www.satsig.net/spectrum-dvb-satellite.htm
wxw
Best regards, Eric.
Back to top
 
 
IP Logged
 
Pages: 1