You make the assumption that the Tropos nodes have little to no attenuation between them, which is a poor assumption. A useful exercise is to drive around and make a list of Metrocom nodes. You'll find that a very small percentage have LOS or even near-LOS to each other. Metrocom certainly was able to provide ubiquitous coverage long before the muni Wi-Fi was all the rage. Where was your physics then?

-Matt

Brian Webster wrote:

HP likes to design these Tropos networks by never having more than 2 hops
before it gets put on some sort of backhaul. This in theory works well but
in reality, you still run out of 2.4 GHz channels to place the access nodes
on. Remember each radio/mesh unit is at the same height as every other one
thus firing their signal directly in to the antenna of all neighboring
nodes. The users may not see the noise but node to node traffic certainly
hears it. When the mesh radio is deaf because of noise, the network just
plain fails to work. End of story. Mesh will simply not work on a loaded
residential user based system without a lot more spectrum. People are trying
to fight the laws of physics. Ask any ham radio guy about this. When they
originally built packet radio networks back in the early 90's, they found
you needed separate channels to make it work (and that was only 1200 baud).
San Francisco, Philly and any other muni network are going to fail based on
this problem. The idea and premise of a muni network is solid based on the
points Matt Larsen brought up but as Jack and others have stated, they have
been sold on all of the positive benefits but never get told the
limitations. The typical IT mentality is that they can throw more money at
the problem to increase capacity. This is simply not true based on the
limited number of useable channels. Sad thing is there will be a lot of
taxpayer money wasted to prove this point.



Thank You,
Brian Webster
www.wirelessmapping.com <http://www.wirelessmapping.com>


-----Original Message-----
From: Jack Unger [mailto:[EMAIL PROTECTED]
Sent: Monday, April 24, 2006 1:22 PM
To: WISPA General List
Subject: Re: [WISPA] Pioneering Wi-Fi City Sees Startup Woes


Dawn,

Thanks for posting the St. Cloud PepLink and HP info.

Using standard CPE (PePLink)is very good but using Tropos nodes is very,
very bad. Very bad because they only have one single 2.4 GHz radio so
after 2 or 3 hops, all the throughput capability is gone not to mention
that the interference level from having all the access and backhaul
packets colliding on 2.4 GHz (along with any WISP and other 2.4 GHz
network packets) will slow all the networks (muni and WISP) down
further. I hate to "finger" anyone but Tropos' stubborn refusal or
inability (anyone at Tropos listening???) to produce a 2-band mesh node
is going to doom them to failure along with any big city that deploys
their nodes without an extremely efficient point-to-multipoint backbone
design on 5 GHz.

jack


Dawn DiPietro wrote:

http://www.peplink.com/060306.php

Date: March 7, 2006*
PePLink announces as the official Citywide Wireless CPE provider for
City of St. Cloud in Florida  *

*Hong Kong, Mar 7, 2006 - *PePLink, a leader in citywide WiFi wireless
broadband devices today announced the City of St. Cloud, FL, a suburb of
Orlando, has chosen PePLink to be the official wireless CPE provider for
the Cyber Spot, the City's 100% free citywide high-speed wireless
Internet service.

With a reliable, secure, ease of use wireless CPE - PePLink Surf, every
citizen or business in the city of St. Cloud can connect to the citywide
wireless network at a high speed. The CPE greatly enhances the
throughput and reliability of both up and down link compared with a
wireless-enabled computer desktop or notebook computer.

The simple true plug and play nature of the PePLink Surf helps the
citizens in St. Cloud to bring the wireless signal indoors with ease. At
the same time, the PePLink Surf units can be remotely managed, monitored
and provisioned by PePLink's carrier-grade management and reporting
solution, PCMS (or PePLink Centralized Management System). This can
ensure a scalable and rapid rollout of the wireless systems within a
short period of time. This eliminates an onsite installation charge.

"Being chosen by City of St. Cloud has further endorsed our capability
to offer reliable wireless solutions to municipal wireless networks
built with mesh network technology," said Alex Chan, Managing Director
of PePLink. "PePLink Surf together with PCMS is the complete solution
specifically designed for today's citywide wireless networks."

PePLink Surf series consists of Surf 200BG and Surf 400BG. For more
information on PePLink Surf series, please visit http://www.peplink.com
<http://www.peplink.com/>.




Marlon K. Schafer (509) 982-2181 wrote:

roflol

The city is selling "signal boosters" (I read that as amps) to anyone
that wants them for $170?

Oh man, this deployment is gonna come CRASHING down.  Hard.

It's really too bad these people are too ignorant, stubborn or just
plain stupid to call any of us in to help.

sigh

Marlon
(509) 982-2181                                   Equipment sales
(408) 907-6910 (Vonage)                    Consulting services
42846865 (icq)                                    And I run my own wisp!
64.146.146.12 (net meeting)
www.odessaoffice.com/wireless
www.odessaoffice.com/marlon/cam



----- Original Message ----- From: "George" <[EMAIL PROTECTED]>
To: "WISPA General List" <wireless@wispa.org>
Sent: Monday, April 24, 2006 7:07 AM
Subject: [WISPA] Pioneering Wi-Fi City Sees Startup Woes


http://news.yahoo.com/s/ap/20060424/ap_on_hi_te/muni_wi_fi_hiccups

I am not a fan of muni wireless.

George
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--
Jack Unger ([EMAIL PROTECTED]) - President, Ask-Wi.Com, Inc.
Serving the License-Free Wireless Industry Since 1993
Author of the WISP Handbook - "Deploying License-Free Wireless WANs"
True Vendor-Neutral WISP Consulting-Training-Troubleshooting
Our next WISP Workshops are April 12-13 and April 26-27
Phone (VoIP Over Broadband Wireless) 818-227-4220  www.ask-wi.com



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