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10 mile point to maultipoint

Author
28 Mar 2005 11:16 PM
Shampoo Store
Has anybody used Navini for WIFI?

We are looking for a WIFI or WIMAX products that can do point to multipoint
10mi.

Any suggestions?

Thanks in advance.

Tracy

Author
29 Mar 2005 3:40 AM
Mack
It can be done, but it isn't
easy and it's not for everyone.
In the Wi-Fi "shootouts" a pair
of hams came up with 65 miles.
But, for the usual wi-fier probably
a half-mile. For the long range
stuff large exponentional antennas
accurately aimed etc. are needed.
Luck
Author
29 Mar 2005 4:13 AM
Shampoo Store
We are going to place the AP on a 400 foot tower. We are going to lease a
spot at 225 feet.

Hope this is high enough to get 10 miles.

--


Show quoteHide quote
"Mack" <gat***@webmail.co.za> wrote in message
news:4248ce87_5@newsfeed.slurp.net...
>
> It can be done, but it isn't
> easy and it's not for everyone.
> In the Wi-Fi "shootouts" a pair
> of hams came up with 65 miles.
> But, for the usual wi-fier probably
> a half-mile. For the long range
> stuff large exponentional antennas
> accurately aimed etc. are needed.
> Luck
>
Author
29 Mar 2005 5:11 AM
atec
Shampoo Store wrote:
> We are going to place the AP on a 400 foot tower. We are going to lease a
> spot at 225 feet.
>
> Hope this is high enough to get 10 miles.
>
http://www.radiolabs.com/stations/wifi_calc.html
  have fun .
Author
29 Mar 2005 5:06 PM
Jeff Liebermann
On Mon, 28 Mar 2005 22:13:47 -0600, "Shampoo Store" <GoAway@spam.com>
wrote:

>We are going to place the AP on a 400 foot tower. We are going to lease a
>spot at 225 feet.
>
>Hope this is high enough to get 10 miles.

Hope is a good thing.  Calculations are better.

See:
  http://www.connect802.com/height.htm
10 miles requires that you only be 38ft above the average terrain to
keep from hitting the curvature of the earth.  At 225ft, you can go
about 40 miles before running into the ground.

Any other calculations will require some input like frequency, tx
power, receive sensitivity, modulation rate, antenna gains, coax
losses, and path obstructions.  Lacking those, there is always hope.


--
Jeff Liebermann    je***@comix.santa-cruz.ca.us
150 Felker St #D   http://www.LearnByDestroying.com
Santa Cruz CA 95060    AE6KS  831-336-2558
Author
29 Mar 2005 6:39 PM
dold
Jeff Liebermann <je***@comix.santa-cruz.ca.us> wrote:

> Any other calculations will require some input like frequency, tx
> power, receive sensitivity, modulation rate, antenna gains, coax
> losses, and path obstructions.  Lacking those, there is always hope.

http://www.craig-bartell.com/ documents a 7KM link.
He talks about using topo and aerial photo maps to document the terrain
changes between the two points, looking for path obstructions.

There are commercial services that do the same thing, but I seem to have
lost the references (too pricey for me).

--
---
Clarence A Dold - Hidden Valley (Lake County) CA USA  38.8,-122.5
Author
29 Mar 2005 7:18 PM
Jeff Liebermann
On Tue, 29 Mar 2005 18:39:13 +0000 (UTC),
d***@XReXX10Xmi.usenet.us.com wrote:

>Jeff Liebermann <je***@comix.santa-cruz.ca.us> wrote:
>
>> Any other calculations will require some input like frequency, tx
>> power, receive sensitivity, modulation rate, antenna gains, coax
>> losses, and path obstructions.  Lacking those, there is always hope.
>
>http://www.craig-bartell.com/ documents a 7KM link.
>He talks about using topo and aerial photo maps to document the terrain
>changes between the two points, looking for path obstructions.
>
>There are commercial services that do the same thing, but I seem to have
>lost the references (too pricey for me).

I was commenting on the usual lack of numbers necessary to do such
calculations.  Incidentally, 802.11b/g tends to having timing problems
at about 10 miles.

For coverage and point to point links, I use (free) Radio Mobile:
  http://www.cplus.org/rmw/english1.html
with the SRTM (shuttle radar topography mission) 1 arc sec maps.
  ftp://e0mss21u.ecs.nasa.gov/srtm/United_States_1arcsec/1arcsec/
The program will download and optionally save the maps as needed and
can use them in the original zipped format.

See the "path profile" example at:
  http://www.cplus.org/rmw/rme.html
for typical output.

I also use various Topo programs to generate point to point path
profiles of the terrain, and then just use a ruler or drawing program
to connect the end points.  It's not as accurate and offers no help
with Fresnel Zone clearances or terrain irregularities, but works well
enough for testing simple clearance.

In this case, the OP is doing point to multipoint which requires an
map area coverage simulation to see what areas will work.  Here's a
very bad example of a 3D VHF coverage model for a local ham radio
repeater. 
  http://www.LearnByDestroying.com/maps/k6bj3-3d.jpg
A 2.4Ghz model will be different.  I can post better examples if
necessary.


Drivel:  About 40 linear feet of bookshelves just peeled themselves
off the wall and onto my kitchen table.  I guess I'm not a great
carpenter.  Kinda reminds me of the 1989 earthquake.  I know what I'll
be doing for the next few days.  Argh...


--
Jeff Liebermann    je***@comix.santa-cruz.ca.us
150 Felker St #D   http://www.LearnByDestroying.com
Santa Cruz CA 95060    AE6KS  831-336-2558
Author
29 Mar 2005 8:14 PM
dold
Jeff Liebermann <je***@comix.santa-cruz.ca.us> wrote:
> On Tue, 29 Mar 2005 18:39:13 +0000 (UTC),
> d***@XReXX10Xmi.usenet.us.com wrote:

>>http://www.craig-bartell.com/ documents a 7KM link.
>>He talks about using topo and aerial photo maps to document the terrain
>>changes between the two points, looking for path obstructions.

> I also use various Topo programs to generate point to point path
> profiles of the terrain, and then just use a ruler or drawing program
> to connect the end points.  It's not as accurate and offers no help
> with Fresnel Zone clearances or terrain irregularities, but works well
> enough for testing simple clearance.

Craig went through great pains to plot the clearances across the terrain,
noting the altitude at every contour line on the map.  That sounded like an
awful lot of detailed work.  The commercial solutions that I looked at the
time were only for certain areas, and were pricey.  If there are free
solutions that have appeared in the last four years, I wouldn't have
noticed. 

---
Clarence A Dold - Hidden Valley (Lake County) CA USA  38.8,-122.5
Author
29 Mar 2005 4:20 AM
atec
Mack wrote:
> It can be done, but it isn't
> easy and it's not for everyone.
> In the Wi-Fi "shootouts" a pair
> of hams came up with 65 miles.
> But, for the usual wi-fier probably
> a half-mile. For the long range
> stuff large exponentional antennas
> accurately aimed etc. are needed.
> Luck
>
>
The fun bit is aiming .. 10 miles is very achievable but the aiming .
Author
29 Mar 2005 5:23 PM
Jeff Liebermann
On Tue, 29 Mar 2005 14:20:57 +1000, atec <"atec77(ate***@hotmail.com>
wrote:

>Mack wrote:
>> It can be done, but it isn't
>> easy and it's not for everyone.
>> In the Wi-Fi "shootouts" a pair
>> of hams came up with 65 miles.
>> But, for the usual wi-fier probably
>> a half-mile. For the long range
>> stuff large exponentional antennas
>> accurately aimed etc. are needed.
>> Luck

>The fun bit is aiming .. 10 miles is very achievable but the aiming .

Bah-humbug.  Aiming even farther distances is easy if you do some
preparation.  The problem is that the boresight alignment of most high
gain dishes and panels is not exactly the same as the maximum lobe of
the antenna.  I clamp on a cheap plastic rifle telescope, point it at
a known source of 2.4GHz (away from any reflections or edge
diffraction), and align the telescope to agree with the antenna gain
maxima.  I carefully drag it to the site, get some lunatic to haul it
up the tower, mount it, make it vertical with an electronic level, and
aim it at the other end of the link with the telescope.  It usually
works the first time.  The antenna must be assembled before transport
to the mountain top which may be a handling problem for big dishes.
Also, it's a good idea to think about where to clamp the telescope so
that it doesn't hit the tower or mounting (oops). 

I recently borrowed a $100 green laser which can certainly be seen at
4 miles, and will probably work much farther.
http://www.thinkgeek.com/gadgets/lights/5a47/action/



--
Jeff Liebermann    je***@comix.santa-cruz.ca.us
150 Felker St #D   http://www.LearnByDestroying.com
Santa Cruz CA 95060    AE6KS  831-336-2558
Author
29 Mar 2005 8:15 PM
SID
Shampoo Store wrote:
> Has anybody used Navini for WIFI?
>
> We are looking for a WIFI or WIMAX products that can do point to multipoint
> 10mi.
>
> Any suggestions?
>
> Thanks in advance.
>
> Tracy
>
>

I suggest WRAP boards + Atheros 5004x + StarOS.
It's very good solution for long range links 2,4 or 5GHz + very stable
system.

SID
Author
30 Mar 2005 1:16 AM
Shampoo Store
WOW!

Thanks all for your input. I will keep you posted on what we do. We have to
get this system up in the next 3 months.
We are looking hard at the http://www.navini.com/index.htm system seems
nice.

Thanks again,

Tracy

--
Show quoteHide quote
"Shampoo Store" <GoAway@spam.com> wrote in message
news:EamdnaKIeYzCDdXfRVn-sQ@comcast.com...
> Has anybody used Navini for WIFI?
>
> We are looking for a WIFI or WIMAX products that can do point to
> multipoint 10mi.
>
> Any suggestions?
>
> Thanks in advance.
>
> Tracy
>