John et al
    How would wireless work? I would like to link several (at least one )with  my
house. I was considering a distance of several miles. I was thinking of using a
cell phone which was part of the remote station. It would be nice to use the
internet to get ones data. Does anyone know where I can find out about using the
internet for sensor monitoring? Internet sensor monitorring for dummys? :)
Regards
Barry


John Hernlund wrote:

> Angel,
>    You will run into a whole lot more complexities and problems by laying
> cables (and probably expense if you are doing things on a kilometer scale!).
> The only way to avoid signal loss or distortion using cables is by digitizing
> at the sending end of the line, which brings you back to the same situation as
> before.  This is a classic problem which has been aching for a better solution
> for over 100 years.  Contrary to popular belief, electric signals do not
> simply zip from one end of a cable to the other at the speed of light with
> arbitrary accuracy.  This is due to the finite resistance, capactitance and
> inductane in metal wires due to intrinsic defects in chemistry that make it
> non-ideal.  The actual equation describing the transmission of a signal is
> given by the transmission line equation, which is a second order differential
> equation similar to the one for the damped seismometer.  To transmit signals
> you have to set the unit capacitance and inductance of your line to a
> specified value using actual electronic rigs.  This is the reason why we can't
> build phone modems faster than 56Kbps.  The unit capacitance and inductance is
> set to frequencies corresponding to the human voice...  The only way around
> this problem is to use fiber optics, which is becoming less expensive over
> time but is still costly to install.
>
> John Hernlund


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