Tooway Out Link Budget
Outlink from gateway hub to remote customer VSAT site.
Uplink from gateway (bw=1030 MHz):
The outlink comprises 4 carriers per beam, comprising 3 carriers of 52 Msps plus 1 carrier of 40Msps, making a total used bandwidth of approx 206 MHz, out of the allocated 236 MHz per beam. Each gateway transmits to 10 customer beams. Total uplink bandwidth per polarisation = 5 x 206 = 1030 MHz (1 HPA)
Uplink satellite G/T assumed to be (-3 dB contour) +50.6dBi - 3 - 10 log (400) = 21.5 dBK
Each of two gateway HPAs is rated 350 watts multi-carrier operating composite power at the multi-carrier operating point -1.5 dB out. Comtech Xicom Model number XTD-500KaL. 0.5 dB switch/waveguide/feeder loss.
Downlink to customer (bw=236 MHz):
EIRP, for each beam, towards the beam centre = 50W + 50.6 dBi = 67.6 dBW
Operating EIRP towards the -3dB edge of beam remote sites = 67.6 - 3 = 64.6 dBW
The input figures above are all my guesses and estimates. You need to overwrite the figures with your own assumptions.
Amend any white boxes and then click the calculate button to obtain results in the green boxes.
* Recent spectrum measurements suggest there are 3 carriers of 52 Msps and 1 carrier of 40 Msps. The total occupied bandwidth corresponds to use of the 236 MHz of Ka band bandwidth per beam. Total bit rate estimated as 3x130 + 1x100 = 490 Mbit/s per beam in clear sky.
Any problems or comments please e-mail Eric Johnston
Copyright 23 Feb 2012 Satellite Signals Ltd All Rights Reserved