[MLB-WIRELESS] World Wifi record

[David Nuttall]

Hi Peter,

Here's what Radio Mobile thinks of the path from Mt. Dandenong to Mt. 
Buninyong.  The signal predicted is somewhat lower than what would be 
expected using raw path loss, antenna gains, feeder loss, power etc.  I 
used a clear spot with no trees and a sharp falloff on the East side of 
Mt. Buninyong for one end of the link.  I used GHO as the other end only 
because it's in my database, obviously we'll find another spot.

http://www.ratbaggy.net/wireless/GHO-Buninyong.PNG

Radio Mobile uses the Longley-Rice model to predict radio propagation 
producing a median value.  It even takes into account how "carefully" 
the link was sited and climate.  The figures predicted by this model 
should be quite attainable in real world situations.

http://flattop.its.bldrdoc.gov/itm.html

Regards

Dave


On 2/01/2012 12:52 PM, Peter Berrett wrote:
> Ok Let's do a sample calculation now based on the actual equipment I own
> I'll use the calculator at
> http://www.afar.net/rf-link-budget-calculator/
> We'll assume that the setup at Binunyong has the maximum power output 
> made up of 30db gain dish plus 8db power output and -2db cable loss = 
> 36 dbm maximum legal power
> At my end on Mt Dandenong a 24 dbm ex galaxy dish plus 14 dbm power 
> and allow 2dbm cable loss with a Ubiquity bullet with -95 db receiver 
> sensitivity @ 1Mb/s
> That should give a receive signal strength of -84.3 dbm with a fade 
> margin of 10.7db
> Not a huge margin to play with but arguable doable. The Ubiquity will 
> probably do 256kbs at -100 or -105dbm so that should give a bit more 
> elbow room.
> cheers Peter
> org.au/mailman/listinfo/melbwireless 
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