[MLB-WIRELESS] Question on omni and directional antennas on long haul connections

[Ben Anderson]

Think of it more like signal-noise...

If you have a big megaphone, people with bad hearing can hear you (the
megaphone just puts more sound out in one direction -- ie higher gain
antenna).  also, if you put the megaphone to your ear, you can hear quiet
people (ie people further away) better.

A higher gain antenna can both send and receive better...   If you add up
the end-end gain, ie gain of the transmitter amplifier, the loss in the
cable, the antenna losses (backwards, etc), the antenna gain, the path loss,
the receiving antenna gain & loss, the cable loss, and then the cards
receive gain, you'll come out with a total gain/loss number.  If the number
is positive, you should get it to work.  The more positive, the better it
works.

Hopefully that makes it a little easier for you to visualise...

Ben.


> Quick question on omni's and directional antennas.
> I think I know the answer, but probably not silly to verify this.
>
> Not being an expert (or even close!) on this stuff, I am confused on the
> issue of range.
> With "long haul" I am referring to greater than 5km.  Probably 10km in
this
> case but would like to know for other distances.
>
> On long haul connections, it would seem two directional antennas would be
> better as the signal is more focussed.
> What about if I set things up with one directional and one omni.
>
> The effective range for the directional would be better than the omni.
> I would think normally for a long haul you would have two directional
> antennas.
> Does using only one directional allow you to increase the effective range
> for the omni as well?  (I am guessing no)
>
> If the omni is sending a radio signal, and it has a finite range that is
> less than the distance to the directional, then I can't see how it would
> work.
> Therefore the omni would set the maximum range between the two antennas.
> Would using the directional at one end (as opposed to a second omni)
extend
> the range potentially?  (again I am guessing no)
>
>
> Regards,
>
> Steven Anderson
>
>
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