[ILUG] The things we'll do for broadband...

[Greg Farrell]

> I know that some of you guys participate in wireless wan's, and I'd like some feedback
> if you have anything to offer. If I was to PTP wirelssly across 7 to 8 miles, what is the
> best wireless to use? 802.11 or something else? 

802.11b can do 7 or 8 miles with decent antennas. We've got bigger links
in DublinWAN and a lot of the other members of IrishWAN would too.

However you absolutely have to have line of sight plus a bit (as it's a
curved volume of space, not just a single straight line you'll be
filling).

Do you have line of sight to where you're trying to connect to? If you
don't then you'll have to do something like the midwestWAN guys have
done and put repeaters boards on hilltops :) And if those hilltops don't
have power, then you're talking about soekris boards with car batteries
and either charging them regularly, or wind or solar chargers.

It's likely to be very difficult. If you still want to do it, then I'd
suggest joining the midwestWAN mailing list (http://www.midwestwan.org/)
as they have more experience with long distance wireless country links
than any other non-commercial group in ireland.

> Am I to expect latency problems?
> 
No, radio waves travel at the speed of light. I've seen latencies <10ms
for multiple mile connections and most of that is the protocol and
hardware itself . The distance doesn't affect the latencies to a degree
anybody would be noticing, but if you have a weak signal and dropped
packets that you'll notice alright.

> Where's best to look for cost effective linux compatible equiptment?
www.fab-corp.com sell good antennas and lucent cards. Any card with a
prism2 or hermes (lucent) chipset will work perfectly in linux. So will
some other chipsets but these are the 2 most commonly used chipsets in
the IrishWAN. However check out someplace like seattle wireless for a
review of the different cards. There can be a huge difference between
even different cards with the same prism2 chipset. I've a senao with a
receive sensitivity about 5 db better than my dlink. 

Both the hermes and prism2 are supported by the orinoco_cs driver
(prism2 since about 2.4.18) There are also hostap drivers that allow
prism2 cards to function as software access points. 

try irc.irishwan.org channels #irishwan or #midwestwan if you've any
questions.

  Greg