"Mountain Mike^^" <rukidding@aol.com> hath wroth:

>Well, nice links, Jeff. One more question, please.

Groan. Why me?

>These guys:
>http://meraki.com/products/outdoor/>
>
>Seem to already make what I had in mind. Seeing as I don't have to re-invent
>the wheel, are you saying that this (apparently a mesh for hobby types) has
>the inherent problems you just mentioned?

Yep. Overly simplified, you have several problems:
1. You're building a WISP (wireless internet service provider) but
are not very aware of how much work that really involves.
2. Mesh networks can be made to work and certainly have their place.
Servicing non-paying neighbors is not my idea of one of those. Others
(such as Earthlink, Meraki, and various manufacturers will disagree).
3. Delivering reliability and quality service via Wi-Fi is a dubious
proposition mostly due to self-interference.
4. Mesh systems do not scale very well. The problem is that you
discover this only AFTER you spend considerable money. Anything can
be made to work on a small scale.

Also, I can tell you did NOT read the MIT Roofnet article or you would
have some questions regarding thruput and reliability limits.

>So, the result is what I want, but I should consider another design? What do
>you have in mind? (gotta be wireless for the ususal reasons).

Well, you could just join Meraki and try their system. It's not that
expensive and certainly cheaper than a do it thyself system. If mesh
is what you want, you'll certainly get a clue on how it works very
quickly. If that's too much trouble, go unto the Google (free) Wi-Fi
complaint and help message board, and see what manner of problems a
real mesh system can generate. Remember, as system operator, owner,
and chief technologist, *YOU* get to answer these type of questions.
<http://groups.google.com/group/Google-WiFi-Network/topics>

As for what I had in mind, I'll answer your questions after you answer
mine. For example, how big is 6 blocks in feet, meters, cubits, or
furlongs? That's not intended to irritate you. It's because wireless
networks are designed to operate in specific environments and
topologies. What's suitable for a small coffee shop hot spot, is not
suitable for "illuminating" an office building or apartment complex.
Give me some numbers and I'll gladly spend your money for you.

>Maybe a simple POE with long shots? Or what?

Dream on. Sounds like you're thinking of an omnidirectional antenna.
Yeah, that might work for starters, but has some rather severe
limitations, especially when it comes to minimizing interference. I'm
a big fan of "sector antenna", where you have multiple access points
and multiple 90 or 120 degree sectors per access point. However, I
can't tell if this is suitable for whatever you're doing.

>(BTW, this is going to be a lab experient similar to the Roof Net guys....)

Yep. Learn By Destroying (tm). Nothing like repeating their mistakes
on a small scale. I recall the definition of insanity was doing the
same thing multiple times and expecting different results. As I
mentioned before, you're problems are NOT going to be technical.
They're going to be administrative and system management. Simply
identifying the cause of problems, separating them between user and
system problems, and doing something about it at 4AM, is going to be a
major challenge. That's why I wanted you to start with a small scale
system. You'll get all the experience with irate customers
immediately and will not have to wait until the system grows to get
the experience. Also no need for a mesh with a small system. I have
a neighborhood wireless and wired LAN that I run. I often regret
doing it simply because of the weird problems that tend to appear at
odd times. For what it's worth, I tried to use old 802.11b junk
radios and am now replacing them with much better and more reliable
802.11g equivalents.

There are other mesh networks out there being used. We have one
locally:
<http://www.surfnetc.com/mp_perform.asp>

Some light reading from my bookmark mess:

An Experimental Scaling Law for Ad Hoc Networks. (Also applies to
mesh)
<http://black.csl.uiuc.edu/~prkumar/ps_files/exp.pdf>

Doing mesh the right way, using multiple radios per node:
<http://www.belairnetworks.com/about_belair/solution.cfm>
<http://www.belairnetworks.com/resources/documentation_display.cfm?c_id=10>

Some comments on whether mesh networks scale:
<http://www.smallworks.com/archives/00000072.htm>
<http://wifinetnews.com/archives/003972.html>

Some articles on various mesh networks (2004):
<http://www.moskaluk.com/papers.htm>

Meshbox:
<http://www.locustworld.com>

OLPC (One Laptop Per Child) Mesh WIKI:
<http://wiki.laptop.org/go/Mesh_Network_Details>

Where some of the WISP crowd posts:
<http://isp-lists.isp-planet.com/isp-wireless/archives/>

--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558