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net
05-22-08, 06:04 PM
in aiming for the highest powered wireless device for a desktop pc it
occurrs to me there must be something better than the long-range pci and
pcmcia cards I've seen for sale. Is there such a device or are we all stuck
with these cards? I know about yagi antennas and such and I know the antenna
is important for range and power but I wanted to start with the
transmitter/reciever first and see what the best thing around was. I'm
interested in fixed location equipment, I don't need mobility. Thanks for
any pointers.

Paul
05-23-08, 05:33 AM
net wrote:
> in aiming for the highest powered wireless device for a desktop pc it
> occurrs to me there must be something better than the long-range pci and
> pcmcia cards I've seen for sale. Is there such a device or are we all stuck
> with these cards? I know about yagi antennas and such and I know the antenna
> is important for range and power but I wanted to start with the
> transmitter/reciever first and see what the best thing around was. I'm
> interested in fixed location equipment, I don't need mobility. Thanks for
> any pointers.
>

Something you should investigate, before going further, is the FCC
(or your local equivalent thereof), has rules for both unlicensed and
licensed uses of the airwaves. That means, I cannot emit more than
a certain power level, on my RF transmitter, unless I want to get
in trouble. The rules are there, to allow the multiple users of these
services, to all play together.

http://www.ddj.com/architect/184411700

If you use a wireless product, complete with original antenna, then
you can be sure you're staying within the rules. That would be a PCI
card with the antenna that came with the product, or a PCMCIA card
with the antenna that came with the product. Not with an amplifier
strapped to the thing, or large high gain antenna.

The FCC may not be driving around in a truck, looking for trouble-makers.
They'll instead be triggered by complaints. Say, for example, a local
cellphone operator, is suffering service outages in your neighborhood.
The FCC man comes to investigate, finds the offending transmitted frequencies,
uses a few antenna trucks to triangulate the source. Then you get the
knock on the door.

I can give you a more concrete example. In my city, one day, all the garage
door openers that operate on a certain RF frequency, stopped working. (Some
people couldn't get their garage door open.) It was discovered, that a powerful
transmitter was operating in the city. (One theory was, it was located on the
roof of a certain embassy!) It took several days, before the problem "went away",
without any details being released to the press about the offender. So, if
there is an offense, like illegal power levels, used on an RF device, finding
and tarring the individual takes time.

If you want to read some amusing articles on Wifi and distance, try

world's record wifi

http://www.engadget.com/2007/06/19/venezuelans-set-new-wifi-distance-record-237-miles
http://www.dailywireless.org/2003/01/06/worlds-longest-wi-fi-connection/

I think I read an article in the past, about one of those mountain to
mountain project, which went into some details, about things like
whether the time constants in the standard protocol, allowed distances
like that or not. And you can see in that picture, that they're using a
pretty fancy high gain antenna.

HTH,
Paul

LR
05-23-08, 06:52 AM
Paul wrote:
> net wrote:
>> in aiming for the highest powered wireless device for a desktop pc it
>> occurrs to me there must be something better than the long-range pci and
>> pcmcia cards I've seen for sale. Is there such a device or are we all
>> stuck
>> with these cards? I know about yagi antennas and such and I know the
>> antenna
>> is important for range and power but I wanted to start with the
>> transmitter/reciever first and see what the best thing around was. I'm
>> interested in fixed location equipment, I don't need mobility. Thanks for
>> any pointers.
>>
>
> Something you should investigate, before going further, is the FCC
> (or your local equivalent thereof), has rules for both unlicensed and
> licensed uses of the airwaves. That means, I cannot emit more than
> a certain power level, on my RF transmitter, unless I want to get
> in trouble. The rules are there, to allow the multiple users of these
> services, to all play together.
8><

Zen.co.uk?
From 2004
<http://www.ofcom.org.uk/radiocomms/ifi/licensing/classes/rlans/technical/wireless.pdf>
2006
<http://www.ofcom.org.uk/consult/condocs/powerlimits/statement/statement.pdf>

kony
05-23-08, 10:24 AM
On Fri, 23 May 2008 00:04:10 +0100, "net"
<mickeymouse@hollywood.com> wrote:

>in aiming for the highest powered wireless device for a desktop pc it
>occurrs to me there must be something better than the long-range pci and
>pcmcia cards I've seen for sale. Is there such a device or are we all stuck
>with these cards? I know about yagi antennas and such and I know the antenna
>is important for range and power but I wanted to start with the
>transmitter/reciever first and see what the best thing around was. I'm
>interested in fixed location equipment, I don't need mobility. Thanks for
>any pointers.


You may have better range with a mimo or 802.11n (external)
router operating in bridge mode, but of course having it
external is simply to allow better placement and aiming of
the antenna without the inherant loss of a longer RF
connecting cable to the antenna(e).

You wrote highest powered though and Paul already covered
the issue there. They are set up with inbuilt power limits
to make them legal for sale to unlicensed customers, as
equipped (w/original antenna).

A better question is what is your specific need for this
equipment? In a fixed location there are more options than
only trying to get from one client to (whatever the other
end is, server or router or client or ...), for example
running some ethernet cable to an access point nearer the
system, or if you're trying to bridge a greater distance
outside you would want to mount an antenna on the roof,
higher up, again with a bridge config at the antenna so you
have negligible cable loss.

If your needs are more simple, the basic thing to avoid
doing is having the PCI card blocked by that large hunk of
metal that is a system case. Get (whatever) any product
that has the antenna away from the case and in difficult
areas that is directional and aimed at the other end (while
checking signal strength report from computer). If you can
find reviews on whatever you're considering, so much the
better, it is often a buyers market so what you end up with
could reasonably be determined by the sales available at the
time unless the environment is difficult enough you will
need enterprise rather than consumer grade gear.

tg
05-25-08, 08:18 AM
"kony" <spam@spam.com> wrote in message news:bmnd341f4rfcpqahbnn1tqqcc6rpuukdr7@4ax.com...
> On Fri, 23 May 2008 00:04:10 +0100, "net"
>
>
> You may have better range with a mimo or 802.11n (external)
> router operating in bridge mode, but of course having it
> external is simply to allow better placement and aiming of
> the antenna without the inherant loss of a longer RF
> connecting cable to the antenna(e).
<snip>

okay thanks for your help kony. I think based on what you said a long range PCI card with
external antenna is the best place to start.