Which Part of Part 15?

[ad5mb]

I have encountered quotations from a portion of Part 15 which say, approximately, that the EIRP can exceed 36 dbm if a directional antenna is used. The transmitter must be reduced by 1 db for every 3 db of antenna gain in excess of 6 db.

Nobody cites which part of part 15 contains this statement. I'm trying to find it at the FCC site, but the FCC regs exceed the FAA regs in their ability to induce sleep.

If anyone can cite the reg in question, please do.

[M/Q]

It depends on the band 11b is 15.247 and 11a is 15.407. This link is very helpful and accurate in finding out where some of the information is hidden.

http://www.lns.com/papers/part15/

Again what you are citing is dependent on the band. It also refers to a point to point link versus point to multi-point. The FCC is willing to allow more power if the link is confined to a narrow beamwidth.

[codeman14150]

How much power can I transmit with in my Point-to-Point system?

According to FCC regulations, 2.4 GHz Part 15.247 point-to-point transmitters may use a 30 dBm transmitter with a 6 dBi antenna. For a 3 dB increase in antenna gain, the transmitter power output must be reduced by 1 dB. Power is measured at the antenna connector, so subtract any cable loss between the amplifier and the antenna. Refer to the following table. (also see Canadian Rules)



Power at antenna (dBm/watts) Max Antenna Gain (dBi) EIRP (dBm) EIRP (watts)
30 dBm (1 W)
6 36 4
29 9 38 6.3
28 12 40 10
27 dBm (500 mW)
15 42 16
26 18 44 25
25 21 46 39.8
24 dBm (250 mW)
24 48 63
23 27 50 100
22 30 52 158


Above information from below site:
http://www.wlanantennas.com/wlan_faq_fcc.htm

[ad5mb]

Thank you, mpkn3rd, codeman. I got what I needed from mpkn3rds link.

What I needed was this:

Title 47 CFR 15.247 (b) (4) (i)

I work with engineers and scientists on a government contract. You never tell an engineer or scientist "You can do this." They want to know you did your research. They want to hear "According to Title 47 CFR 15.247 (b) (4) (i), you can do this".

[codeman14150]

Thanks ad5mb, I will keep this in mind the next time I need to write a proposal to a scientist or government customer. Your tips are appreciated :D