Matt,
        I make that assumption based on the node density that some of these
networks are being designed for to accommodate the little or no gain
available on the antenna systems of the user unit laptops and PDA's. The
people who are trumping up these networks are trying to lull the people with
money in to thinking they can build a seamless network. To do this they spec
the systems for high node density to keep the signal level up down on the
ground for the users. When they locate them on light poles on the same
streets they certainly will have many situations where other nodes will have
a lot of strong signal visible to them from neighboring nodes. When you look
at a coverage footprint for a node when you have to assume the specs from a
laptop unit you clearly see that it does not cover much area, IT mentality
says, just put more nodes up then. Tropos nodes do have attenuation between
them but with each node using an antenna with gain they don't have the
attenuation "between nodes" that the network was designed for.



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


-----Original Message-----
From: Matt Liotta [mailto:[EMAIL PROTECTED]
Sent: Monday, April 24, 2006 1:58 PM
To: [EMAIL PROTECTED]; WISPA General List
Subject: Re: [WISPA] Pioneering Wi-Fi City Sees Startup Woes


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
>>>>--
>>>>WISPA Wireless List: wireless@wispa.org
>>>>
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>>>>
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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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>WISPA Wireless List: wireless@wispa.org
>
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