Wireless Ethernet Bridging at 200 Kilometers

Is there a way to do such a thing, either an amateur/poor (wo)man's
do-it-yourself approach, and/or a commercial system for say less than
$10,000 (excluding towers). With no intermediate relay points; and LOS or
possibly NLOS.

Of course, one could just do dial-up, or do VPN through an ISP
at both ends, but I am wondering if there is a not too
costly through-the-air option at this distance.

c hore wrote:

> Is there a way to do such a thing, either an amateur/poor (wo)man's
> do-it-yourself approach, and/or a commercial system for say less than
> $10,000 (excluding towers). With no intermediate relay points; and LOS or
> possibly NLOS.
>
> Of course, one could just do dial-up, or do VPN through an ISP
> at both ends, but I am wondering if there is a not too
> costly through-the-air option at this distance.

I don't believe it will work for this range. The longest range for a WLAN I
read about was somehwere around 190km (as far as I remember).
The stations had a direct view line (down from the mountains) and the
connetion was very unstable.

Thomas

(E-Mail Removed) (c hore) wrote:
>$10,000 (excluding towers). With no intermediate relay points; and LOS or
>possibly NLOS.

Well, you are going to require 2,000-foot towers on both ends, but
other than that it's LOS!

http://www.keytelemetering.com/9600_Antenna.htm

On Mon, 09 Aug 2004 13:50:56 -0400, William P.N. Smith wrote:

>(E-Mail Removed) (c hore) wrote:
>>$10,000 (excluding towers). With no intermediate relay points; and LOS or
>>possibly NLOS.
>
>Well, you are going to require 2,000-foot towers on both ends, but
>other than that it's LOS!
>
>http://www.keytelemetering.com/9600_Antenna.htm

just a thought, how long before we get SISPs (Satellite ISPs )
allowing us to bounce our signals straight up to space and back ?

On Mon, 09 Aug 2004 19:38:20 +0100, (E-Mail Removed) wrote:

>On Mon, 09 Aug 2004 13:50:56 -0400, William P.N. Smith wrote:
>
>>(E-Mail Removed) (c hore) wrote:
>>>$10,000 (excluding towers). With no intermediate relay points; and LOS or
>>>possibly NLOS.
>>
>>Well, you are going to require 2,000-foot towers on both ends, but
>>other than that it's LOS!
>>
>>http://www.keytelemetering.com/9600_Antenna.htm
>
>just a thought, how long before we get SISPs (Satellite ISPs )
>allowing us to bounce our signals straight up to space and back ?
>
they already exist !

http://internet.about.com/library/aa...et2_081302.htm

"c hore" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Is there a way to do such a thing, either an amateur/poor (wo)man's
> do-it-yourself approach, and/or a commercial system for say less than
> $10,000 (excluding towers). With no intermediate relay points; and LOS or
> possibly NLOS.
>
> Of course, one could just do dial-up, or do VPN through an ISP
> at both ends, but I am wondering if there is a not too
> costly through-the-air option at this distance.

Really the best option in this case is to let the local telephone company
carry the infrastructure and buy their services. If you can get DSL at both
locations you can do the VPN thing, tunneling is another option, or even
with dial up, though it will be slow. Wireless is pretty much out as far as
the DIY stuff is concerned.
I have been told of someone that is using wireless at 100 miles which would
be about 160 KM or so but I haven't seen their setup and they are running
some large antennas and towers.
Since I work for an ISP I have some experience helping customers with this
type of stuff but it's usually contracted out.
AG

On 9 Aug 2004 10:08:19 -0700, (E-Mail Removed) (c hore) wrote:

>Is there a way to do such a thing, either an amateur/poor (wo)man's
>do-it-yourself approach, and/or a commercial system for say less than
>$10,000 (excluding towers). With no intermediate relay points; and LOS or
>possibly NLOS.

Sure. However, do you have line of sight? Last time I checked, the
earth is not flat. At 200km (125 miles) you'll need some rather
substantial towers to clear the earths curvature. My guess(tm) is
about 750ft high towers. Unless you live on a mountain, this is not
gonna work.

The record for the Wi-Fi shootout last week was 55 miles with no
amplfiers.
http://www.wifi-shootout.com
Note the size of the antennas. The all time record is 310km by
Alvarion from ground to a weather balloon.
http://www.alvarion.com/RunTime/Corp...=298&type=item
Note the 6 watts of power output.

It is possible to build a radio link that works over 200km, but there
are going to be some serious limitations. It will need to be at a
lower frequency, licensed by your favorite regulatory agency, and
limited in bandwidth to perhaps 4800 or 9600 baud. Not exactly high
speed, but it will work.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

On Mon, 09 Aug 2004 19:56:10 -0700, Jeff Liebermann
<(E-Mail Removed)> wrote:

>On 9 Aug 2004 10:08:19 -0700, (E-Mail Removed) (c hore) wrote:
>
>>Is there a way to do such a thing, either an amateur/poor (wo)man's
>>do-it-yourself approach, and/or a commercial system for say less than
>>$10,000 (excluding towers). With no intermediate relay points; and LOS or
>>possibly NLOS.
>
>Sure. However, do you have line of sight? Last time I checked, the
>earth is not flat. At 200km (125 miles) you'll need some rather
>substantial towers to clear the earths curvature. My guess(tm) is
>about 750ft high towers. Unless you live on a mountain, this is not
>gonna work.
>
>The record for the Wi-Fi shootout last week was 55 miles with no
>amplfiers.
> http://www.wifi-shootout.com
>Note the size of the antennas. The all time record is 310km by
>Alvarion from ground to a weather balloon.
> http://www.alvarion.com/RunTime/Corp...=298&type=item
>Note the 6 watts of power output.
>
>It is possible to build a radio link that works over 200km, but there
>are going to be some serious limitations. It will need to be at a
>lower frequency, licensed by your favorite regulatory agency, and
>limited in bandwidth to perhaps 4800 or 9600 baud. Not exactly high
>speed, but it will work.

what about the satellite internet would that be any use to her ?

On Tue, 10 Aug 2004 08:53:45 +0100, (E-Mail Removed) wrote:

>what about the satellite internet would that be any use to her ?

I only have limited 2nd hand experience with satellite internet.
Frankly, I don't know if satellite will work for an unspecified
application.

The big problem is always the huge latency.
http://www.satsig.net/latency.htm
It takes about 140 msec to go from the ground to the bird. A ping
requires two trips through the satellite so it will return about 560
msec minimum latency. That will kill anything in real time such as
VoIP.

Latency also limits the thruput because of the max window size of
64KBytes before stopping for an acknowledgement. For example, if you
can only send 64KBytes (512Kbits) and have a 1 second latency, then
your maximum thruput is:
512Kbits / 1 second latency = 512Kbits/sec.
This is why Starband, DirecPC, and DirecWay are intentionally limited
to about 400Kbits/sec. They could deliver more but you wouldn't be
able to use it.

The uplink is also incredibly slow. I think it's something like
16Kbits/sec. This is adequate for typical web surfing and email, but
forget it for anyting that requires outgoing bandwidth.

The various satellite internet providers have done some optimizing,
buffering, compression, cacheing, and tweaks to improve the situation,
but I suspect that they're only partially successful in dealing with
the aformentioned problems. For example, to use a satellite ISP with
a VPN has always been a problem because the cacheing mechanism breaks
down when faced with encrypted (and therefore random) data.
http://www.groundcontrol.com/turbo_vpn_001.htm
I have no clue if it actually works.

About a year ago, I helped setup (stood around sipping soda while
everyone else did the work) a DirecWay system on a mountain top radio
site. The plan was to use it for VoIP audio backhaul to expand a wide
area radio network. It worked well enough but the receiver voting
system could not handle the 1 second delay. So, it's being used for
telemetry and SCADA. Lacking other alternatives, it was good enough.

About 2.5 years ago, I scribbled a web page with alternative internet
access solutions for the San Francisco Bay area.
http://www.LearnByDestroying.com/nooze/wireless.htm
It's totally obsolete today, but does have some interesting items. I
included a "science fiction" section which includes schemes that
involve tethered balloons, airplanes flying donuts, weather balloon
repeaters, low earth orbiters, TV station rebroadcasters, FSO (free
space optics), and other oddities. Many are still in existance under
different names and investors, and may be found with Google.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

On Tue, 10 Aug 2004 06:12:32 -0700, Jeff Liebermann
<(E-Mail Removed)> wrote:

>On Tue, 10 Aug 2004 08:53:45 +0100, (E-Mail Removed) wrote:
>
>>what about the satellite internet would that be any use to her ?
>
>I only have limited 2nd hand experience with satellite internet.
>Frankly, I don't know if satellite will work for an unspecified
>application.
>
<snip very intriguing stuff>

do those satellite ISPs have servers orbiting up there ?
if so are they linux or windows ?