From: Phill Kenoyer (phill_at_consumerdatacorp.com)
Date: 2002-07-28 05:03:06 UTC
I'm using Linksys WMP11 PCI cards for my network. I have a 12dBi
omni-directional on my roof and I have a connection 3 miles away using
the same PCI card and a 24dBi dish (primestar with a cantenna/yagi).
This is working really good. I get about 50% link quality, but I only
need a 1mb/s connection (internet surfing). I can also connect with no
problem from my Mac in my house through the roof.
I have been told that the Linksys cards are not very good, but I have not found any problems yet.
I am setting up a WISP and so far its working well. I will need to add more access points when I get more people online.
I also have a question for anyone to answer. What is the ratio of AP's to Users that works well for a 1mb connection? Also, has anyone got PPPoE setup on their wireless yet? I'm getting ready to set that up.
On Saturday, July 27, 2002, at 02:55 PM, Eric Johanson wrote:
> On Sat, 27 Jul 2002, Tom Mercelis wrote:
>
>> Hello,
>>
>> I want to turn my linux box into a Wireless Access Point. It has one
>> Free ISA slot and several PCI slots.
>> The (at this moment only one) linux client pc only has a free PCI
>> slots.
>> I also have an iMac which one day has to be removed from the wired
>> network and will need to have access to the wireless network.
>> I've been looking the last days on several sites about this subject,
>> and
>> there seems to be such a variety of choises. But some of the technical
>> data I don't understand:
>> What does it mean when a card has RF output power 15 dBm
>
> It's the output power. It can be converted to milliwatts; 15dBm = 30mw,
> 20dBm = ~100mw. The higher the power, the longer you can go (provided
> you
> don't have much noise from other 2.4ghz stuff).
>
>> , and a sensitivity of -85 dBm @ 11 Mbps,
>
> The more sensitive cards can pick a signal out from the noise better.
> Again, improves your distance. Think of RF as talking to someone. If
> you
> are at a rock concert, you need to talk much louder to be heard. Also,
> someone with better hearing may be able to understand you better than
> someone with worse hearing. It's the same concept with RF.
>
>> and about antennas: what does xx dBi mean?
>
> Dbi = isotropic Db level. Higher the number, higher the gain. Keep in
> mind that you'll lose coverage area, depending on the type of
> antenna. I
> have a 24dbi parabolic dish (directional antenna) that has a 7 deg.
> beam width. You don't want that, unless you are building p2p links. I
> suspect you won't need an antenna at all, but you might depending on the
> setup of your hostap-PC.
>
>> The distance between the computers will be at most 30 meters (100 feet)
>> through the walls of my house.
>
> Well, that depends on what's in the walls & the amount of noise. I hope
> you don't have a 2.4gzh cordless phone, those will kill 802.11b. Do
> some
> tests with two cards in iBSS (adhoc) mode.
>
>> I don't feel like bungling with antennas, so wich product should I
>> chose
>> that meets all these requirements?
>
> Well, if you want to run hostap, you might end up needing an antenna. A
> standard PC power supply is very noisy (on RF). Having the card INSIDE
> the pc case will limit your range by quite a bit. Also, even with the
> card's antenna sticking out the back, it may end up being un-seeable
> from
> the 'front' of the case. A small omni/sector antenna to get you away
> from
> the PC will help quite a bit.
>
> As for products:
>
> Be careful selecting a prism2 based card. While there are many out
> there, most of them have really, really bad receive sensitivity. I can
> tell you
> to stay away from the dlink DWL650 (I've not used the + or H models),
> and
> 3com airconnect cards. But I have yet to have played with a prism card
> that works better than my lucent silver card or cisco 350.
>
> The problem: Lucent cards aren't support as AP's under hostap.
>
> The solution (!?): Use lucent cards in your clients, but find a
> higher-power prism2 based card for your AP. 200mw cards are out, but
> that's probably overkill for your needs. Zocomax (sp) I hear makes a
> great prism2.5 based 100mw card with an external antenna connector.
> I've
> not used one, but I've heard good results. I'm not sure about hostap
> mode
> on this card. Maybe somebody else will share some details on this list.
>
> -Eric
>
>
>