[amsat-bb] Re: 150 cubesats to provide global WIFI multicasting

[Fabio Azzarello]

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 at 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 at 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
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