Our pings at Seiko were < 250mS RTT. Maybe we did things differently in the
80's....
IMHO the proper way to calculate space-earth propagation would be to adjust
the speed of light formula for frequency and apply a delay K based on LOS
losses at that frequency and account for additive delays, such as hardware,
wired links, etc. It can be several hundred microseconds at 10GHz.
Also, what packet size are you calculating for? All these little adjustments
make a difference in your calculations...BUT in my EXPERIENCE..ping times
are LESS in the real world than when calculated. Go figure.....
The formulas you want used to be on the old NIST site...not sure if they still
maintain it. At least you can get the wire link propagation figures there.
jk
At 07:59 AM 2/3/2001, you wrote:
>James S. Kaplan wrote:
>
> > How do you calculate this?
>
>Like this.
>
>You have to traverse the 22400 mile link from earth to satellite four
>times. Ping request goes up, request comes down, reply goes up, reply
>goes down.
>
> 4 * 22400 mile
> --------------- = 0.480 seconds
> 186000 mile/sec
-----------------------------
James S. Kaplan KG7FU
Eugene Oregon USA
[EMAIL PROTECTED]
http://www.rio.com/~kg7fu
ICQ # 1227639
Have YOU tried Linux today?
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