Re: 150 cubesats to provide global WIFI multicasting
Just in case anyone was curious about the practicality of actually transmitting WiFi from a cubesat, I did a quick link budget. Based on typical 802.11 specs, the MDS of a receiver is about -90 dBm. The path loss at 2.4GHz between a ground station and a satellite overhead in a 600Km orbit is a little over 155 dB. Assuming a zero gain antenna on the typical WiFi client radio, the required EIRP from the cubesat is in the neighborhood of 4KW. I don't think we are quite there yet with current solar cell technology.... not to mention the difficulty keeping the PA cool :)
- Howie AB2S
Yes, a dish needed, ISS HamTV provides a good illustration of the requirements to achieve a 2 Mbps downlink at 2400 MHz.
73 Trevor M5AKA
On Monday, 10 February 2014, 18:16, Howie DeFelice howied231@hotmail.com wrote:
Just in case anyone was curious about the practicality of actually transmitting WiFi from a cubesat, I did a quick link budget. Based on typical 802.11 specs, the MDS of a receiver is about -90 dBm. The path loss at 2.4GHz between a ground station and a satellite overhead in a 600Km orbit is a little over 155 dB. Assuming a zero gain antenna on the typical WiFi client radio, the required EIRP from the cubesat is in the neighborhood of 4KW. I don't think we are quite there yet with current solar cell technology.... not to mention the difficulty keeping the PA cool :)
- Howie AB2S _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Hello everybody, I agree with Trevor, GS requirement for the 2.4 GHz band are quite "challenging".
Anyway, I have another question, what kind of orbit this constellation will be designed for? If it is less than 500 km, how many *months* will it last?
73s Fabio iz5xrc
On Mon, Feb 10, 2014 at 8:43 PM, M5AKA m5aka@yahoo.co.uk wrote:
Yes, a dish needed, ISS HamTV provides a good illustration of the requirements to achieve a 2 Mbps downlink at 2400 MHz.
73 Trevor M5AKA
On Monday, 10 February 2014, 18:16, Howie DeFelice howied231@hotmail.com wrote:
Just in case anyone was curious about the practicality of actually transmitting WiFi from a cubesat, I did a quick link budget. Based on typical 802.11 specs, the MDS of a receiver is about -90 dBm. The path loss at 2.4GHz between a ground station and a satellite overhead in a 600Km orbit is a little over 155 dB. Assuming a zero gain antenna on the typical WiFi client radio, the required EIRP from the cubesat is in the neighborhood of 4KW. I don't think we are quite there yet with current solar cell technology.... not to mention the difficulty keeping the PA cool :)
- Howie AB2S
Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Hello all. Even though I got the old ISA slotted PC to work once again with XP, and my KCT card, I decided it'd time to retire my ISA XP machine for another avalable computer in my down sizing shack. I found a 'spare to someone's needs' LVB kit, and will assemble it in an AMSAT custom enclosure I ordered from AMSAT this morning. After reading all the emails about USB solutions I thought LVB Tracker was my best solution I thank all who came up with alternative's, I didn't realise there were so many possible choices. Thanks again...
73 Jeff KB2M
HelloFabio, fromexperiencewithFITSAT-1,thelaunchtook placefromtheISS( orbit ~ 400km). Thelifetime willbeupapprox.9months. But, thisisinfluencedbytheshapeandsizeof thesatellite.
73´s de Michael, DD5ER
Hello Fabio, from experience with FITSAT-1,the launch took place from the ISS( orbit ~ 400km). The lifetime will be up approx. 9 months. This is consistent with the observations of other satellites in this orbit height. But, this is influenced by the shape and size of the satellite.
73´s de Michael, DD5ER
participants (5)
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Fabio Azzarello -
Howie DeFelice -
kb2m＠comcast.net -
M5AKA -
Michael R. Lengruesser