Today, 07:47 -0400, wrote:

>    Quoting Don Russell <>:
>    >
>    > Anyone try the 128K high speed data while mobile?
>    >
>    > I mean in a vehicle above say at a constant 30-45 mph.
>    >  What about at higher speeds? Would it work
>    > to say a helicopter or airplane orbiting over the city
>    > where the access point is? Or would the Doppler shift
>    > be too much? I am wondering if it could be used to
>    > feed data to/from a CAP spotter heli/plane should the
>    > proper equipment be installed in the craft?

Doppler shift is negligible. The real problem with mobile operation 
(especially at 1,2GHz) is the constant change RF path due to reflections 
on ground structures (eg. buildings). We have used with success a webcam 
mounted on a moving vehicule. At the push of a button, it was transmitting 
one jpeg image. It was working fine at highway speed in the open field, 
i.e. in plain view of the repeater site that was some 35km away.

We have not done yet any experiment from a plane or helicopter, but we 
have all reasons to believe it would work.

>    >
>    >
>    > Also would like to know of anyone successfully using VOIP.
>    > Is it possible to send voip over the high speed link.

As for VoIP, the half-duplex nature of this beast (and it's rather long 
turn around time), makes it virtually impossible.

'73 - Pierre

Pierre Thibaudeau

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