Not really, Fresnel zone size is a function of frequency and distance between 
the two end points. The zone is football shaped with the widest part of the 
zone half way between the two end points. Antenna patterns have nothing to do 
with Fresnel zone size. 

 

Here is a Fresnel Zone size calculator with a good basic illustration:   
http://www.wirelessconnections.net/calcs/FresnelZone.asp

 

 

 

Thank You,

Brian Webster

www.wirelessmapping.com

www.Broadband-Mapping.com

 

From: Clay Stewart [mailto:[email protected]] 
Sent: Thursday, April 10, 2014 2:02 PM
To: Brian Webster; WISPA General List
Subject: Re: [WISPA] Who is using Towercoverage.com ?

 

Yes, good way to look at it Brian, thanks.

 

So, is there a minimum height per frequency... say for 900Mhz "you should never 
shoot less then x feet', like less then 6'?

 

On Thu, Apr 10, 2014 at 10:14 AM, Brian Webster <[email protected]> 
wrote:

Fresnel zones are 180 degrees out of phase with even and odd numbered zones
(1st, 2nd, 3rd and so on). When you design a path you strive for an exposed
Fresnel zone of between 1 and .6 of the first zone, meaning you use the
ground/trees/obstructions to block the second and higher numbered zones
(this is only partially blocking the zone at the bottom). This minimizes the
cancelling effect giving an apparent gain.

A good visual example of this is to take a Flashlight such as a Mag light
with an adjustable beam and shine it against the wall to see the circular
pattern. Carefully look at that pattern and you will see light and dark
rings, these are your Fresnel zones and the lighter ones are the odd
numbered zones. The idea is you keep the first bright zone and eliminate the
rest. This is why going higher is not always better on a PTP path to get
more signal once you have cleared obstructions, going higher can expose more
even numbered Fresnel zones with the phase cancelling and a reduction in
signal due to same.


Thank You,
Brian Webster
www.wirelessmapping.com

www.Broadband-Mapping.com


-----Original Message-----
From: Matt Hoppes [mailto:[email protected]]
Sent: Thursday, April 10, 2014 9:07 AM
To: [email protected]; WISPA General List
Subject: Re: [WISPA] Who is using Towercoverage.com ?

Can you explain this more?  This isn't what I was getting at... but since
you brought it up and it's been brought up before it might be worth
explaining in more detail.  I'm familiar with the concept but still can't
grasp why it works.


Matt Hoppes
Director of Information Technology
Indigo Wireless
+1 (570) 723-7312 <tel:%2B1%20%28570%29%20723-7312> 

On 4/10/14, 9:04 AM, Brian Webster wrote:
> Matt,
>
>                 Signals do change as you change height as you expose
> or conceal the even number Fresnel zones.
>
>
>
> Thank You,
>
> Brian Webster
>
> www.wirelessmapping.com <http://www.wirelessmapping.com>
>
> www.Broadband-Mapping.com
>
>
>
> *From:*[email protected] [mailto:[email protected]]
> *On Behalf Of *Matt Hoppes
> *Sent:* Wednesday, April 09, 2014 3:24 PM
> *To:* WISPA General List
> *Subject:* Re: [WISPA] Who is using Towercoverage.com ?
>
>
>
> Signals don't change as you increment heights. You're asking for real
> time foliage mapping. Not going to find it.
>
>
> On Apr 9, 2014, at 3:18 PM, Josh Luthman <[email protected]
> <mailto:[email protected]>> wrote:
>
>     I'm not talking about customers plotting where their address is.
>      What I'm getting at is if I have a customer called in, I'd like to
>     just punch in the location and then see if they'll work at ground
>     level or how high we need to get off the ground and see the signal
>     change as I increment height.
>
>
>
>     Josh Luthman
>     Office: 937-552-2340
>     Direct: 937-552-2343
>     1100 Wayne St
>     Suite 1337
>     Troy, OH 45373
>
>
>
>     On Wed, Apr 9, 2014 at 3:16 PM, Clay Stewart
>     <[email protected]
>     <mailto:[email protected]>> wrote:
>
>     Josh. You can. Just put the web snip on a website. If need help can
>     walk u through later today. Our websire customer lookup...
>     http://www.towercoverage.com/iframemc.asp?mcid=1223 
> <http://www.towercoverage.com/iframemc.asp?mcid=1223&Acct=2910> &Acct=2910
>
>     On Apr 9, 2014 3:08 PM, "Josh Luthman" <[email protected]
>     <mailto:[email protected]>> wrote:
>
>         I'm having a hard time adjusting to this from Radio Mobile.
>          There's all the same "stupid" interface shortfalls, for example
>         wanting to know what a customer's CPE would be without adding a
>         site and putting them in the same list.  I feel with technology
>         as it is, it shouldn't be so convoluted to simply put a dot on a
>         map and see what the signal would be from a tower while being
>         able to adjust the elevation on the fly.
>
>
>
>         I'm wondering if there's another list/forum for this service,
>         too.  There's no way I'm going write a bible of questions for
>         support, it doesn't make a whole lot of sense for either of us.
>
>
>         Josh Luthman
>         Office: 937-552-2340 <tel:937-552-2340>
>         Direct: 937-552-2343 <tel:937-552-2343>
>         1100 Wayne St
>         Suite 1337
>         Troy, OH 45373
>
>
>
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-- 


-- 
SCS     
  Clay Stewart 
  CEO, Tye River Farms, Inc., 
  DBA Stewart Computer Services   
  434.263.6363 O 
  434.942.6510 C
  [email protected]  
“We Keep You Up and Running” 
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