"Jeff Liebermann" <jeffl@cruzio.com> wrote in message
news:bkqud3p8sgimll424kde8srob227ifc5rj@4ax.com...
> "Dana" <raff242@yahoo.com> hath wroth:
>
>>Sounds like a typical day in the office for cellular engineers. Ray
>>tracing
>>methods are now becoming popular in rf propagation software solutions.
>
>>http://www.wavecall.com/accurate.php
>
> Methinks we're talking about two different types of simulations here.
I was replying to your reply about the impairments like multipath has on the
system
> nevtxjustin@gmail.com said:
> "Fortunately bandwidth modeling for WiFi is very easy...when you
> are a professional in the biz."
> which I took to mean simulating bit/packet error rates, retransmission
> algorthm effects, thruput, error correction effects, carrier to
> jamming ratio, doppler damage, Eb/No falloff, power control effects,
> and reliability/availability.
I took his statement in the context of the ongoing thread, about preserving
bandwidth for certain users.
You seem to have interpreted the
> original statement as coverage area, which really is a trivial
> exercise until you get down to urban jungles and indoor propagation.
> (Incidentally, thanks for the Wavecall link. I was trying to remember
> their URL).
No problem about the url.
When I read your reply which included multipath and other rf impairments, I
thought you were saying rf planning fro mesh networks is almost impossible.
>
> What I use for propagation is Radio Mobile:
> <http://www.cplus.org/rmw/english1.html>
> using SRTM data for the wide areas, and some "borrowed" LADAR data for
> the local urban jungle. It blows up in the near field, but then I
> don't care much about that. I should finish this web site one of
> these daze:
> <http://802.11junk.com/cellular/>
> <http://802.11junk.com/cellular/jeffl/SVLY-PGE/>
>
> Simulating Wi-Fi is far more complicated. With a propagation and
> coverage model, there are really only a few variables, which are
> mostly signal strength and postion. All the other variables are
> static for a given map. With modulation and data simulation, there
> are a huge number of variables, most of which I listed previously.
> However, the purposes are very similar, which it to calculate how many
> radios can function in a given geographic area, and at what
> performance levels. That's not very easy as witnessed by none of the
> MATLAB models I posted go beyond the idealized RF model (no
> interference, no reflections, no multipath, no doppler, no MIMO, no
> mesh, no long distance timing, etc).
>
> Incidentally, I don't think I'll be buying MATLAB. $1,900 for MATLAB,
> $3,000 for SIMULAB and my guess is about $7,000 for all the RF/COMM
> modules I'll need.
> <http://www.mathworks.com/store/productIndexLink.do>
Yep. for those of us not lucky enough, mathlab is kind of out of reach on
the affordability scale.
>
>
> --
> Jeff Liebermann jeffl@cruzio.com
> 150 Felker St #D http://www.LearnByDestroying.com
> Santa Cruz CA 95060 http://802.11junk.com
> Skype: JeffLiebermann AE6KS 831-336-2558