>From: "George Lappas" <el96077_at_central.ntua.gr>
>> I am trying to find a way to model a building (a house or a block of
>> apartments).
From: Jim Lux <jimlux_at_jpl.nasa.gov>
>I've done some limited modelling using NEC for buildings by creating
>the building as a huge array of wires with lots of resistance. Other
>than burning CPU cycles, however, I don't know if it actually matches
>the real thing.
...
>I am sure someone has done this (lots of modelling of urban
>environments in the wireless industry), but I haven't seen any obvious
>papers in a casual look through the IEEE search engine. Maybe it's
>all considered proprietary (good propagation models are worth money
>when choosing cell sites)? Pointers or suggestions, anyone?
Try RF and cellular industry journals such as RF Design. One old
article I saved, "Limits of Range Calculation" by Kasmir 8/93
discusses how antenna height and obstacles not only produce an
attenuation, but increase the attenuation slope 20db thereafter!
Initially the signal decreases with the square inverse of distance,
then to the 4th power after 1 obstacle, the the 6th power, et. That
sounds extreme. But as a practical issue, theory doesn't model complex
real environments well.
One time attn. hits:
Window in brick wall 2 dB
metal frame glass wall 6 dB
office wall 6 dB
metal door office wall 6 dB
cinderblock 4 dB
metal door in brick wall 12 dB
brick wall near metal door 3 dB
Scott
Received on Mon Apr 02 2001 - 06:49:08 EDT
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