Trying to connect TWO ground level indoor city office suite that are
20 miles (32 km) apart wirelessly. They are not in line of sight. At
one site, no equipment can be placed outdoor, and no antenna can be
put up. Ideally no outdoor equipment or antenna at second site either.
Any help would be appreciated. Thank you for your time.
(I initially looked at proxim tsunami 10, but kinda expensive, etc...)

leased lines?

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John wrote:
Depending on your location, we are in an area that has Verizon
BroadbandAccess (avg 500 Kb) and have the Audivox pc5220 cards at each end
(along with VPN software) always on x.25 wireless connection. When we want
to add additional offices, or people with laptops, no problem, takes about a
day to set up a new system.
In case you are curious, it's a real estate firm, we keep adding offices in
new areas, and the agents love mobile access to the network with their
laptops.

Thanks for the replies, we are hoping to get away from paying monthly
fee of the leased lines or wireless service providers. From my
understanding the Verizon service will require the computer to connect
to the tele-co's cell network then to your own company's VPN via
internet. But, thanks for the info; if anyone can suggest something
else (another product, etc), it would be great.

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Is there anywhere part way that both can see (tall buildings/mountains/etc?)
Out west we use reapeters to get an indirect line of sight...Any possibility
of that for your situation?


John wrote:
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jmcz***@hotmail.com (John) wrote in news:8280e9ff.0502251006.2dfca8c6
@posting.google.com:

there is absolutely no way this will work w/o outdoor antenna's.

Even the Proxim Tsunami's will require external antennas and LOS.

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Due to my lack of knowledge and faulty understanding, I just figured
the device can use their case as an antenna, or work without an
antenna. As an aside, I also get confused with terms such as: 0dbi
gain antenna, build-in antenna, integrated antenna, embedded antenna,
etc. Got lots to learn... Ideally, I am looking for a set of device to
wirelessly connect my indoor suite that's 20 miles away; that has no
line of sight, using only small-short build-in/integrated/embedded
antenna from the device. Many thanks for for your suggestions and
solutions.

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On Mon, 28 Feb 2005 09:39:56 -0800, John wrote:

To cover a 20 mile path via wireless you will need outdoor antennas.  Even
with a repeater on a mountain/building near the mid-way point of your
path, you will still need to have an outdoor antenna above and away to
protect everyone from RF exposure.

Though some products like the Orthogon Systems Gemini radios will work
non-line-of-sight, there still has to be an RF path--I don't think they
will be too successful installed at ground level at that distance. You can
learn more at http://www.orthogonsystems.com My company is installing some
of these and they work as an Ethernet bridge. What each radio sees on the
wire goes out the antenna and what is received at the antenna is put on
the wire. They can tie two hubs together thus bridging two offices on the
same segment/subnet or be tied to a router at each end, or whatever.

- Nate >>

On 28 Feb 2005 09:39:56 -0800, jmcz***@hotmail.com (John) wrote:

Most of the terms you list are the "gain" of the antenna.  In general,
the antenna gain is measured in dBi or decibels over an isotropic
reference, which is just a hemispherical pattern antenna with unity
gain.  3dBi gain is twice the power delivered.  6dBi is 4 times.  9dBi
is 8 times.  And so on.  When comparing antenna gains, power levels,
or losses, the term is dB or decibels, which is just a ratio.  2 times
is 3dB.  1/2 is -3dB.  1/8 is -9dB.  6dB gain will go twice the
distance.  -6dB loss will cut your range in half.  This is not a
complete explanation but might help.

You didn't bother to describe your preformance specifications.  If you
can tolerate slower speeds, 20 miles is possible.  Not having line of
sight may be fatal but will vary depending on where and how much of an
obstacle is in the way.  The antennas can be indoors as long as they
go through glass windows.  You'll need someone (me?) to calculate the
path loss, fade margin, and evaluate the NLOS path, to determine if
this even has a chance at working.  Email the exact lat-long, to as
much accuracy as you can get, and the altitude of the antennas above
ground level, and I'll grind out a path profile.  If you don't have
about 190ft elevation at each end of the link, forget it as the earths
curvature (67ft) plus the Fresnel Zone clearance (130ft) requirement
will mean the path will hit the ground at midpoint.
  http://www.radiolabs.com/stations/wifi_calc.html

If you can tolerate either 112Kbits/sec thruput, or 750Kbits/sec
(depending on model), the older 900MHz point to point radios might
work.  See:
  http://www.avalanwireless.com/product_list.htm
  http://www.avalanwireless.com/AW900x_Specs.htm
  http://www.maxstream.net
There are other 900MHz wireless vendors but these are the ones I can
recall.  I've never done a 20mile NLOS (non line of sight) link and
suspect that it can't be done unless the obstructions are fairly
modest.  However, it is worth investigating.

Jeff Liebermann <je***@comix.santa-cruz.ca.us> wrote:
Show quoteHide quoteWhat Jeff meant to say, after his geek demonstration, was "It is
an interesting technical problem, but don't waste your time and
money."

On Thu, 03 Mar 2005 13:40:40 -0900, fl***@barrow.com (Floyd L.
Davidson) wrote:

Well, I just really hate to agree with you, but this time you're
correct.  20 miles, NLOS, and no external antennas is fairly close to
impossible.  However, running the numbers doesn't take that much time
and effort and is often fun to see how close one can get.  In some
cases, it's only a minor change to make it work.

At this very moment, I'm fighting the numbers over a rather nasty 12
mile path at 5.6GHz.  The limitations are such that using conventional
hardware and antennas, the fade margin is only about 12dB.  Not
enough.  So I play with bigger antennas, more power, better receiver,
lower bandwidth, fat coax, exotic modulation schemes, and alternative
vendors.  As it stands, I can only change *ONE* of the aformentioned
or I go over budget.  That's the kind of problem I enjoy doing.  (OK,
I'm weird).  It may be a waste of time, but I think it's fun.

As for the geek show, I like to explain my terms, buzzwords, and logic
as I go along.  Not exactly perfectly organized and perhaps a bit
heavy on the buzzwords, but it is what geeks do.

Incidentally, the earth is still flat.  If I roll a bowling ball and
the earth were round, it go faster and faster as it approaches the
edge of the earth until it falls off.  With a flat earth, it would
just slow down and stop, as it obviously does.

Jeff Liebermann <je***@comix.santa-cruz.ca.us> wrote:
Yeah sure.  You like hearing yourself talk!  Which is true of
most geeks.  And in fact *I* enjoy reading your mumblings!

But, when the OP says half a dozen techie terms overwhelm him,
there is no point in responding with dozens more equally
meaningless terms.

Why not give the OP the *benefit* of your technical experience,
which is to say a *clear* expression of the conclusions you come
to.

Once that is out of the way, yeah...  go right ahead and open it
up for discussion with others who enjoy the technical challenge
that the OP's situation presents.  But don't start and end with
that and never bother to actually _help_ nice fellow who gave us
the interesting scenario to play with!

Yer just a luddite.  Haven't you heard of the latest science,
called physics?  It has shown that if the world were round, it
would have to spin, and if it was spinning that bowling ball
would *not* roll down hill at all.

Nope, it would be subject to centrifugal force, and be flung
into outer space!

Therefore, the world is indeed obviously flat.  And, unlike some
people I know, it doesn't spin either.

On Thu, 03 Mar 2005 20:57:49 -0900, fl***@barrow.com (Floyd L.
Davidson) wrote:

Guilty as charged and thanks.  At least someone reads my stuff.

Actually, I was rather careful NOT to lay the buzzwords on too thick.
I did't toss in the traditional 10log(ratio) calculation for
converting ratios to decibels.  I defined all my terms as I went
along.  I used many more examples than definitions.  I was repetative
to emphasize the important points (i.e. 3dB is twice, -3dB is half
power).  I even added something useful, like 6dB is twice the range.
If anything, it was a rather simple explanation of decibels and
antenna gains.

I don't do that very often.  I prefer to offer the OP some data, my
logic, some details, and let them make their own conclusions.  The
extreme case of what you advocate is the unsubstantiated one line
judgement, which I detest.  Should I have said "Don't bother trying
this because I think it won't work"?  That's clear enough and is
derived from my many years doing wireless.  However, it doesn't
explain anything, how I came to that judgement, and offers nothing in
the way of an education.  I suppose I could have added that line to my
long explanation, but I would thought that the OP would read the
details, see the problems involved, and draw his own conclusions.

Perhaps you're right.  I'll start my subsequent posting with an
overall judgement and pontification and then supply the details,
instead of the reverse order.  Incidentally, I do try to answer the
interesting questions as I'm really bored with Windoze related
wireless issues and problems.

Certainly not.  I'm an active proponent of science and a believer that
given enough scientific research funding, I can prove anything.
Science is a good thing.

Thank you.  I knew you would eventually come to the correct
conclusion.  This also explains my dismal bowling scores.  As Newton
said, "an object in motion will remain in motion until someone steals
it" which might also explain the disappearance of the bowling ball off
the edge of the Earth.  The spin of the flat Earth is rather small, as
I notice is it much more difficult to go to work in the morning, than
to return in the opposite direction in the evening.  Obviously, some
force must be at work here.

Incidentally, today and the next 3 days are when the sun goes behind
the geosynchronous satellite belt and causes an outage in DBS (dish)
receivers and DirecWay satellite internet.  The calcs are available
at:
http://www.panamsat.com/global_network/calc_sun_outage.asp
http://www.satellite-calculations.com
If you live in a forest (like me), then it's often difficult to
determine the optimum location for receiving a specific satellite.  At
the calculated time (varies with satellite and lat-long), wherever the
sun shines on your roof, is where a dish can be located.  Have fun,
and don't look directly at the sun (or do my dumb stunt of pointing my
digital camera at the sun).

Incidentally, the Panamsat calculator has a bug.  It won't accept dish
diameters less the 1.0 meters.  Use 1.1 and it will work.

Thanks for all the help and suggestions. At this time, I guess it's
just not possible to get "a set of device to wirelessly connect my
indoor suite that's 20 miles away; that has no line of sight, using
only small-short build-in/integrated/embedded/internal antenna from
the device". It seems, if no (or almost no) antenna is a must, then
the best solutions today is to go thru the big teleco's cell network
(a middleman's network with monthly fees) into the internet then
connect the two sites together. Thank you.

John wrote:
There is another couple possibilities, unfortunately, they both cost monthly
fees/money. If you are in an area that has cable internet, and both sites
already have/can get cable installed, you can use that, or if available in
your area, you can also do DSL.

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