Creating a 10km wireless bridge...pointers?

[Polytropon]

On Sat, 21 Mar 2009 06:43:01 -0600, Modulok <modulok at gmail.com> wrote:
> Something
> like:
> 
> LAN<->BSDrouter<->modem<->Antenna<~~air~~>Antenna<->modem<->DSL

Your BSD router would act as a gateway, eventually using
functions like "IPDIVERT and DHCPd via RF". It would then
serve as an AP, put in simple words. This should be achievable
mostly by means of the base OS.

For the RF transmission part, you will need antennas (yagí
type ideally) with a good signal gain and narrow radiation.
It's possible to build them, but I'm sure they're sold, too.
Optionally, a power amplifier (PA) may be added on both
ends to strengthen the signal if it's too low.

In case you have something in the way that hinders a direct
view from your desired AP to the client (e. g. a mountain),
things get a bit more complicated, a repeater would be needed.
But as long as you can see it, you can connect it. :-)

Coming back to your suggestion, I'd express it as follows:

                                    ~ > ~ >
                                 V           V
              +--------------+   |  < ~ < ~  |
              | wireless NIC |---+           |
DSL in        +--- ^ -- v ---+               |   +--------------+
the wall--*-->| ethernet NIC |               +---| wireless NIC |
at your       +--------------+                   +--------------+
site        your FreeBSD "AP" box                  client's box

* insert modem if needed

I'm not sure why wou want to employ a modem on the client's
site. If it's only about Internet access, it's usable via the
WLAN component already. If you want to handle IP telephony and
multiple clients... well, more complicated, the client's all in
one modem / spliiter / router / DHCP server / firewall / whatnot
would need to connect to the RF "bridge", I'm not sure if this
is possible even if the modem offers WLAN antennas.



> Tips? References? Advice?

Sorry, no. :-) Just some basic thoughts from a radio amateur and
FreeBSD user.



-- 
Polytropon
>From Magdeburg, Germany
Happy FreeBSD user since 4.0
Andra moi ennepe, Mousa, ...