The uplink antenna diameter of the cell phone is imaginary. The number (diameter) is artificial and you need to simply adjust this number to get whatever transmit gain you think is realistic. I have estimated 0 dBi which means omni-directional. This is not unreasonable in that the satellite may not be exactly overhead and the cell phone is unlikely to have a sharp null upwards.
Choose a suitable mobile uplink frequency, say 890 - 915 MHz or 1805 - 1880 MHz (or both, if you fancy a multi band system)
I have guessed the cell phone power output to be 200 mW and carrier bandwidth 170000 Hz. This can easily be adjusted up and down for your refinement.
For the spacecraft uplink antenna I have guessed at 30m diameter. Think in terms of a deployable mesh dish like INMARSAT 4. You need to run the uplink G/T calculation for this separately: e.g. 30m diameter at 1.85 GHz, 65% efficiency and 300K noise temp gives a G/T of about +28.5 dBK The noise temp is high because it looks down at the warm earth, although it will be cooler if you point the satellite uplink antenna at the sea.
On the downlink I have assumed some suitably unusual frequency (34 GHz) for fun. Change it to anything you want.
For the satellite downlink eirp you need to adjust the satellite eirp per 200000 Hz bandwidth till you get an acceptable downlink C/N. In the default example below a downlink satellite eirp of +16 dBW per 200000Hz is just about enough. If the downlink satellite antenna is 43 dBi (e.g. 0.5m dia at 34 GHz) then you need a spacecraft tx power of -27 dBW per 200000 Hz which should not be too difficult to achieve.
Amend all the white boxes freely as you wish and then click any calculate
button to obtain results in the green boxes.
SCPC / DAMA 8kbit/s mesh network
satellite link budget for 1.8m antennas - Skylinx
Data broadcasting or data
distribution satellite link budget
Line of sight link radio budget
- one way - single hop
Satellite TV link budget
calculator
Europe to Africa - Satellite
internet broadband outlink
Africa to Europe -
Satellite internet TDMA return link
Explanation of satellite links
Advertisements:
Broadband satellite internet
access service for US and South America
Broadband direct satellite internet
access service for the Middle East
Satellite internet and
satellite VoIP communications access for Africa
Australia broadband satellite
access
Satellite finder: Calculate dish
aiming and pointing angles for any site
Back to general purpose link budget calculator
Any problems or comments please e-mail
Eric Johnston
Copyright © 9 June 2004 Satellite Signals Ltd All Rights Reserved
Last Revision: 17 March 2005, 30 Sept 2005, 22 Aug 2007.