Re: [Thinkpad] General wireless ISP question(s)

Hi David,

I've been part of a wireless ISP co-op for the last several years. My own
link is almost 13 miles to a repeater site. A few bits from my own experience:

- You definitely want a high-gain grid-dish type antenna (21 to 24 dBi)
mounted on the outside of your house, as high as possible. At 2 miles from
the transmitter, this is not a must, but it's good engineering practice
(avoids spraying your RF around unnecessarily) and you can use all of the
"link margin" you can get in the 2.4 GHz band.

- Use high quality co-ax cable (LMR-400 at least) to connect to an access
point (AP) mounted either inside or outside your house.

- The AP should be one of those that generate a full 100 mW output -- most
of the consumer models do not do this. Our co-op uses Cisco Aironet radios
exclusively for 2.4 GHz 802.11b. My own is a UC-4800E which is
discontinued by Cisco but can still be found on Ebay. It has an external
antenna connector which is connected to an adapter to fit the dish
connector (N-type). An Aironet PCI radio card is another good option. Again
-- make sure to get the 100 mW output model.

- I strongly recommend using a router connected to the AP for your internal
network. Your internal network can be either wired or wireless.

- Don't forget lightning protection for external antennas. See the NEC
(National Electrical Code) for requirements. Get a professional installer
to help if needed.

- If you run a wireless 802.11b network inside the house, set it so the
channel does not overlap with your outside link. There are 11 channnels
designated for 802.11b, but only 3 do not overlab -- 1, 6, 11. This is why
buildings with multiple AP's will only use these channels. Your wireless
ISP should be using one of these -- use one of the others internally.

Due to the accumulation of RF interference in the 2.4 GHz band, our
wireless co-op is in the process of transitioning to using Motorola Canopy
radios on 5.7 GHz for our links. These are more expensive than 802.11b, but
their protocol is much better for longer links in the presence of
interference. You might ask your WISP about their plans to deal with the
continually increasing level of 2.4 GHz noise.

Have fun!

John

At 03:49 AM 8/21/2004 -0500, David Reid wrote:
>Greetings List,
>
>My fingers are crossed, hopefully, I will soon have broadband at my rural
>home,
>via a new upstart local wireless broadband provider. I'm just over 2 miles
>from
>their current transmitter site, can see the tower they're on from my front
>porch
>so I'm hoping that will be an even better advantage.
>
>Anyone else on this list, a fulltime wireless customer? I would be
>interested in
>your comments about the service, maybe some "out of the box thoughts"
>
>Just wondering about a few things,
>
>I've seen external antenna's advertised, for instance, Computer Geeks has
>something that looks like a Pringles Signal finder, advertised as great
>antenna
>for increasing reception.
>
>Is there any means to connect our "xxx p" wireless thinkpads (I have an
>A30p) to
>an external antenna? Do they (ext ant.) really work?
>
>In speaking to the owner of this new company, I asked if it were feasable to
>setup a remote reciever. Much of my office work done outside and
>throughout the
>County. If I were on the fringe of the wireless signal area, he stated I could
>indeed setup a temporary antenna to pick up a signal.
>
>I suppose I'd have to have this connected to a small router or hub and
>hard wire
>via ethernet cable to my Thinkpad?
>
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Received on Sun Aug 22 12:45:41 2004