What is the Max (Unobstructed) Dist for Wireless LAN?

Can anyone help me understand the maximum distance for a wireless LAN --
primary application is web-surfing -- if the distance is essentially an
unobstructed straight line?

Thanks!

Steve

How long is a piece of string ? Most vendors quote 100 - 250m. But even in
unobstructed space there maybe
interference from other radio / microwave signals, no two places are the
same. But it's possible to extend that distance to many miles using external
directional antenna's, but line of sight is a must.
As an example my connection works well between two buildings 75m apart and
trough two sets of double glazed windows at an acute angle. But the signal
varies by moving the AP or receiver by just an half an inch,
USB adapter proved to be better because it's easy to position.
(Draytek Vigor 2600We to Orinoco USB adapter and / or Vigor 520 PC Card)
Regards,
Martin

In article <EZydnfcK4fdjsSCiRVn-(E-Mail Removed)>,
Steve Forrester <(E-Mail Removed)> wrote:
:Can anyone help me understand the maximum distance for a wireless LAN --
rimary application is web-surfing -- if the distance is essentially an
:unobstructed straight line?

Voyager I is about 8.4 billion miles out, and there's no reason in
theory you couldn't do a LAN over to it.

You might want to rephrase your question to specify particular
transmission media and protocols. For example, are you talking 802.11b
over 2.4 GHz wireless?

The major technical reason for distance limitations is that radio
signals [at least of the type that don't need a license] fan out
like any other wave, so the transmitted power becomes spread out over
greater areas. At some point, the received power is going to be less
than the sensitivity of your antenna to distinguish signal from noise.

You could, of course, get around this problem by transmitting a more
powerful signal. The difficulty with that is that there are legal
limits on the signal level you may transmit without a license in most
countries. The limit in the US is noticably higher than the
limit in France -- but the limit in the US is much lower than the limit
in Australia.

Another factor to consider is that the Earth is curved, but the
frequencies of signals used normally travel in straight lines. If your
receiver is far enough away and both antenna and receiver are at ground
level, then true line of sight between the two travels through the
Earth. To correct for this, raise your antenna or transmitter high enough
off the ground that the other device is visible. For example, for 30 km,
you would need about 241 feet of elevation.


The record distance that I've heard for 802.11b is 35.2 miles.
http://iwce-mrt.com/ar/radio_shootout_desert/
--
Scintillate, scintillate, globule vivific
Fain would I fathom thy nature specific.
Loftily poised on ether capacious
Strongly resembling a gem carbonaceous. -- Anon

Can I buy these at Radio Shack???

Steve



"Martin²" <(E-Mail Removed)> wrote in message
news:7Iavb.11043$(E-Mail Removed)...
> How long is a piece of string ? Most vendors quote 100 - 250m. But even in
> unobstructed space there maybe
> interference from other radio / microwave signals, no two places are the
> same. But it's possible to extend that distance to many miles using
external
> directional antenna's, but line of sight is a must.
> As an example my connection works well between two buildings 75m apart and
> trough two sets of double glazed windows at an acute angle. But the signal
> varies by moving the AP or receiver by just an half an inch,
> USB adapter proved to be better because it's easy to position.
> (Draytek Vigor 2600We to Orinoco USB adapter and / or Vigor 520 PC Card)
> Regards,
> Martin
>
>

I am so sorry... Can I 300 ft or 100 m wireless???

Steve


"Walter Roberson" <(E-Mail Removed)> wrote in message
news:bpjevp$70b$(E-Mail Removed)...
> In article <EZydnfcK4fdjsSCiRVn-(E-Mail Removed)>,
> Steve Forrester <(E-Mail Removed)> wrote:
> :Can anyone help me understand the maximum distance for a wireless LAN --
> rimary application is web-surfing -- if the distance is essentially an
> :unobstructed straight line?
>
> Voyager I is about 8.4 billion miles out, and there's no reason in
> theory you couldn't do a LAN over to it.
>
> You might want to rephrase your question to specify particular
> transmission media and protocols. For example, are you talking 802.11b
> over 2.4 GHz wireless?
>
> The major technical reason for distance limitations is that radio
> signals [at least of the type that don't need a license] fan out
> like any other wave, so the transmitted power becomes spread out over
> greater areas. At some point, the received power is going to be less
> than the sensitivity of your antenna to distinguish signal from noise.
>
> You could, of course, get around this problem by transmitting a more
> powerful signal. The difficulty with that is that there are legal
> limits on the signal level you may transmit without a license in most
> countries. The limit in the US is noticably higher than the
> limit in France -- but the limit in the US is much lower than the limit
> in Australia.
>
> Another factor to consider is that the Earth is curved, but the
> frequencies of signals used normally travel in straight lines. If your
> receiver is far enough away and both antenna and receiver are at ground
> level, then true line of sight between the two travels through the
> Earth. To correct for this, raise your antenna or transmitter high enough
> off the ground that the other device is visible. For example, for 30 km,
> you would need about 241 feet of elevation.
>
>
> The record distance that I've heard for 802.11b is 35.2 miles.
> http://iwce-mrt.com/ar/radio_shootout_desert/
> --
> Scintillate, scintillate, globule vivific
> Fain would I fathom thy nature specific.
> Loftily poised on ether capacious
> Strongly resembling a gem carbonaceous. -- Anon

In article <bpjevp$70b$(E-Mail Removed)>,
Walter Roberson <(E-Mail Removed)> wrote:
:The record distance that I've heard for 802.11b is 35.2 miles.
:http://iwce-mrt.com/ar/radio_shootout_desert/

Checking the newsgroup archives, I found a claim of further:
http://www.ronen.ampr.org/wlan.html

Flash news !! Nov 2000 We have installed a working Direct Sequance link
it is a 72 KM Link with 24DBi Antennas on both side and give us a 11MB/s
outpot in Avarage RSSI (Signal ) of -81DBm on the BreezeCom Units

18May-1999 The 100KM Record test was made successfully


Today the 100KM Haifa Tel Aviv test was made and the results were more then expected

The link was Full Quality stable (3 leds on the BreezeCom Units)


We used BreezeCom Units AP and WB with 24DBi Semi Grid Pack Antennas on
both Sides , No amplifier no bulshit

--
What is "The Ultimate Meme"? Would it, like Monty Python's
"The World's Funniest Joke", lead to the deaths of everyone who
encountered it? Ideas *have* lead to the destruction of entire cultures.
-- A Child's Garden Of Memes

Steve Forrester wrote:
> I am so sorry... Can I 300 ft or 100 m wireless???
>
Yup. I installed a 6 Km 54mbit link three days ago. I've done two longer
and thirty shorter than that since I started this hobby just a few months
ago. This Saturday, I'll be installing a 2 Km link. This will be an easy
one. The client only has one PC so I'm going to simply use a pci card to
cable to lightening protection to cable to an 18dbi parabolic grid. The
server side has a 15.4 dbi omni already installed to an AP and they have
direct line-of-sight to one another. The only difficulty I face is the fact
that the weatherman is telling me to expect 5 to 10 degrees F below zero on
Saturday <groan>

I can be as far as 5 miles from my house to access my 802.11g AP (it is
connected to a 15dbi omni) from my laptop via an Oriinico Gold b/g card with
a 12.4 dbi cantenna. I think I could be further away, but I lose
line-of-sight (I live in a valley).

If you are asking if your access point and client card will effectively
communicate with one another at 300 feet without any help. Well, the answer
depends much on your hardware and your enviroment, but that answer is
"probably not". Most people who need to reach beyond 150 feet or so end up
at least using a reflector. You have a lot of options. You can get really
high-end equipment like Orinico. You can add external antennas (if your
hardware supports it). You can build reflectors. You can modify your
environment (cut down trees or other obstructions and get rid of 2.4ghz
phones, microwaves etc). There are not many reasons you shouldn't be able
to find a solution to be able to reach 300 feet. But most consumer grade
equipment isn't likely to be very reliable without any help at that
distance. ---- Maybe, though. You won't know until you try :-)

"i'm_tired" <(E-Mail Removed)> wrote in message news:<xhfvb.260962$Tr4.812870@attbi_s03>...
> Steve Forrester wrote:
> > I am so sorry... Can I 300 ft or 100 m wireless???
> >
> Yup. I installed a 6 Km 54mbit link three days ago. I've done two longer
> and thirty shorter than that since I started this hobby just a few months
> ago. This Saturday, I'll be installing a 2 Km link. This will be an easy
> one. The client only has one PC so I'm going to simply use a pci card to
> cable to lightening protection to cable to an 18dbi parabolic grid. The
> server side has a 15.4 dbi omni already installed to an AP and they have
> direct line-of-sight to one another. The only difficulty I face is the fact
> that the weatherman is telling me to expect 5 to 10 degrees F below zero on
> Saturday <groan>

Hi,

What type of AP you are using?

Rgds,

Mr Magoo

Mr_Magoo wrote:
> "i'm_tired" <(E-Mail Removed)> wrote in message
<snip>
>
> Hi,
>
> What type of AP you are using?
>

In this case, the server-side AP is already installed and happens to be a
Linksys WAP54G. Of the ten most recent I've done, four were Linksys WG
(customer provided), three were Netgear WG (customer provided), and the
remaining three were Orinoco AP-600s (I provided).

I've had one or two "headaches" with the Linksys stuff but they were solved
with firmware upgrades and antenna tweeks. I had a serious problem with one
Netgear WG602 AP that required replacement. The Orinoco stuff is absolutely
wonderful, but the cost can be prohibitive. Those Orinoco AP-600s set me
back more than four times what a Netgear or Linksys AP would, but they are
well worth it for reliable operation and sensitivity.

>I had a serious problem with one Netgear WG602 AP that required
replacement.

Ditto !
Regards,
Martin