seaweedsteve <(E-Mail Removed)> hath wroth:
>Aha. Same people from MIT, I see. Well, no doubt they are a smart
>bunch. Maybe they will get something good together.
I again call to your attention the web page with the performance
summary of the MIT Roofnet system. It's not very impressive and
probably not ready for massive deployment with an average packet loss
of 50% at 1Mbit/sec.
<http://pdos.csail.mit.edu/roofnet/doku.php?id=interesting>
>I was wondering if they had gotten around the single radio repeater
>problems.
Insanity: doing the same thing over and over again and expecting
different results. (Albert Einstein, Rita Mae Brown, and Rudyard
Kipling).
>Looks like not much, but I'm sure it helps that they have
>all matched sets that they are tweaking to work together. I see
>that they don't have WPA yet, but plan to. That would be a
>breakthrough, no? If it worked reliably.
Oh, you want reliability too? Well, you're not going to get that from
even single hop wireless, much less from mesh. There are just too
many sources of interference, too many environmental problems, and too
much abuse to make that happen. Wireless, by its very nature is
unreliable. Now, you can trade other things for reliablity, such as
trading speed, range, features, and latency, but the consumer oriented
wireless market, reliability is the very last requirement.
Most of the wireless mesh vendors offer WPA and WPA2. I know Tropos
and BelAir do.
>On their forums, customers talk about re-starting a lot. Uh-huh.
Different problem, methinks. It's based on the Netgear WGT634U, which
seems to have some "issues". I don't know the details so I won't dig
deeper. If they had a variety of hardware platforms, it might be
easier to assign the blame:
<http://pdos.csail.mit.edu/roofnet/doku.php?id=wgt634u>
I don't think it's the RoofNet firmware as it's based on OpenWRT,
which is quite reliable.
>Seems like they (Meraki) do have a good plan, though. They seem to
>provide the monitoring and hot-spot software and everything, no
>programming skills needed, $60-100 per unit. Of course they are
>charging 20% off every dollar the administrator bills. That's where
>they will make their money if it takes hold as a system.
It's the lowest cost version of consumer mesh networks that has bombed
badly in the past. The last big deployment was when Nokia bought
Rooftop Networks and tried to sell it to ISP's.
<http://www.americasnetwork.com/americasnetwork/data/articlebrief/americasnetwork/412002/34898/article.pdf>
The price is lower and it's being sold directly instead of to ISP's,
but otherwise, it's deja vu.
>How much more would it have cost for them to set these boxes up with
>two radios? $20 more per unit? Or is it not that simple?
Nothing is simple in wireless. A 2nd MiniPCI card inside the box will
add about $50 in hardware costs. However, it will also require
contention logic, antenna combining, RF isolation, and *MAJOR* changes
to the routeing algorithm and MAC layer code. For example, when
Tropos went from their single radio 5210 to their dual radio 5320,
they also added substantial firmware features, such as the ability to
use either radio as a backhaul, dynamically. It also increases
network management complexity. Anyway, as I recall, the large quanity
prices went from about $1,200 per single radio poletop, to about
$2,000 for the dual radio version. I'm guessing on the prices.
Router overview:
<http://www.troposnetworks.com/products/metromesh_routers.html>
Tropos 5210 (one radio):
<http://www.troposnetworks.com/pdf/5210_datasheet.pdf>
Tropos 5320 (two radios):
<http://www.troposnetworks.com/products/pdf/5320_datasheet.pdf>
General mesh article on the one or two radio issue:
<http://www.benchmark.com/news/sv/2006/08_17_2006.php>
--
Jeff Liebermann
(E-Mail Removed)
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http://www.LearnByDestroying.com
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Skype: JeffLiebermann AE6KS 831-336-2558