Re: RE: What dBi 120deg. sector can I use legally w/ 200mW

On Apr 14, 2004, at 10:27 PM, Rodney Milam wrote:

> Apollo,
>
> 1. With 200mW = 23dBm  you can use a 13dBm antenna to stay within FCC
> limits with it being point-to-multipoint.

True only if you're considering EIRP.  You also need to worry about out 
of band emissions, which is why the FCC
wants you to test each antenna+radio combination via certification.

> 2. Studies from Bell Labs a.k.a. Lucent and others have shown that
> horizontal polarization in buildings can increase
>    your range by up to 10 times the range you would get from vertical
> polarization. This is due to the fact that walls
>    are generally thinner than the floors and therefore signals bounce
> off of the floors more than the walls. This gives
>    you a horizontal corridor. With that being said, I am still 
> skeptical
> of it covering the whole building.

Care to cite these sources?

10X range in an environment with a path-loss exponent of 3.0 or more 
would be.. phenomenal.

my answers to the original questions follow:

> 1. What is the highest dBi 120deg. sector can I use with uamplified
> 200mW access point without breaking the law?

Any that have been certified, (and none that haven't) of course.

> 2. I wonder if I would be able to penetrate our stucture, so I could
> serve the units on the other side of the building without doing any APs
> on the other side (the light poles there belong to the city). What
> polarization should I use?

Sadly, polarization isn't your problem.

Your best bet is to get the AP(s) inside the building.

Jim

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