[Cu-wireless] general update:

[Sascha Meinrath]

Yes, we should definitely move forward on both fronts.  If Mark can make
this work, then we'll definitely utilize the technology.  Having a working
prototype up and running ASAP will allow us to employ the knowledge of
other folks whose expertise lies more in the sysadmin and programming
realms.

As a reminder, we'll be meeting this Sunday at 1:30 at the IMC to do more
wireless work.  Dave and I went to Maiko's house last night and started
installing stuff there.  We ran out of time before other committments
kicked in, but we'll keep working on it.

--Sascha



On Wed, 6 Mar 2002, by way of Illustrious niteshad <niteshad at whopper.de> wrote:

> One way to eliminate much of the complexity and expense incurred in our
> currrent plan for Race Street would be to use high gain omni-directional
> antennas.  Guerrilla.net has plans for a 10 dBi vertical collinear array,
> unfortunately, their mathematical theory section is so full of holes that a fishnet
> looks solid by comparision (e.g. they list the speed of light as 300000 m/s,
> it is actually 300000000 m/s) With such basic errors, I do not trust their
> numbers, or their expertise in physical/radio theory.  I am currently
> scouring the ARRL Antenna Handbook for the proper theoretical underpinnings of the
> vertical collinear array.  Once the theory is firm in hand, I could
> probably build two of these antennae for between $20 and $40.  The primary
> radiating elements are thin brass pipe and LMR-200 or LMR-400 co-ax cable.
> (ecommwireless sells LMR-200 for _$0.28/ft._!)
> 	If we replace the 12 dBi Pringles Can yagis with 12 dBi omni-directional
> (omni) antennas, we save cost on our network.  At each node, we need only
> one wireless card, rather than 2 at Maiko's, 2 at Sascha's and 2 at Race and
> Main.  According to my back of the envelope calculations, it will cost
> approx. $944 to run wireless from Zach's to the IMC using weatherproof Pringles
> cans, pigtails, free routers and $80 wireless PCI cards. (I assume that a
> weatherproof Pringles Can costs about $12, the pigtails are known to cost $26).
> 	Using slightly more expensive omnidirectional antennas, the cost actually
> drops to approx. $655.  This is due to the fact that only one antenna, and
> thus one costly wireless card and pigtail, are needed at each node, rather
> than two.  In other words, the more expensive antennas save us 30% of the
> cost in the long run.  I should hasten to add that the $655 figure was arrived
> at by estimating that the omni antenna will cost around $25 to build and
> weatherproof, wireless cards cost $80 and pigtails cost $26.
> 	While I favor the omni in theory, I realize that the goal is to get the
> network up and running as quickly as possible.  Therefore, I suggest that we
> attempt to move forward with the proven Pringles Can design (actually, we
> might want to test the Coffee Can design, as it's simpler, cheaper and
> inherently waterproof.)  If the collinear array proves itself to be superior in
> performance, we can relatively easily replace the directional antennas with
> omnis.  Then we can redeploy the directional antennas and surplus wireless
> cards elsewhere in the community.  Possibly to people within line-of-sight of
> our network who lack the income for internet access.
>
> best regards,
>
> Mark
>
> --
> Sent through Global Message Exchange - http://www.gmx.net
>
>
> _______________________________________________
> Cu-wireless mailing list
> Cu-wireless at lists.groogroo.com
> http://lists.cu.groogroo.com/cgi-bin/listinfo/cu-wireless
>