Re: [Discuss-gnuradio] Daughterboard

[Kelly Martin]

Brook Lin wrote:
> Hi All,
>
> When we use any of the USRP daughterboard to transmit, do we need the
> authorization? For example, FRX900 includes the cell phone bands in US. If
> we use FRX900 to transmit, do we violate the FCC rule? Or, we could legally 
> use any daughterboard on any band that falls in the frequency range of the
> daughterboard?
>
> Thanks,
> Brook
>   
There's four ways you can emit RF and remain within the scope of FCC 
regulations.  First, you can emit RF for the purpose of communication as 
an FCC licensee, pursuant to the rules of the  service in which your 
license is issued.  Second, you can emit RF for the purpose of 
communication not as an FCC licensee, pursuant to the rules in Part 15 
for intentional radiators.  Third, you can emit RF not for the purpose 
of communication pursuant to the rules in Part 15 for incidential 
radiators or pursuant to the rules in part 18 for ISM equipment.  
Fourth, you can emit RF for any purpose pursuant to the terms of an 
FCC-issued Special Temporary Authorization.  Any other emission of RF 
(within the FCC's jurisdiction of 9 kilohertz to 300 gigahertz) is illegal.

In the first case, you must comply with all requirements of the 
regulations pertaining to the service in which you have a license.  The 
thing is, for most services one of the rules is that you may only use 
equipment which has been certificated by the FCC for use with that 
service; using equipment which has not been certificated for use in that 
service is a violation of the rules and is prohibited.  Some services 
permit uncertificated equipment to be used in certain situations, most 
notably the amateur radio service.  An amateur radio licensee may use 
just about anything he or she wants to emit RF as long as his or her 
emissions are consistent with the regulations in Part 97 and with "good 
engineering and good amateur practice" (§97.1).  Since the USRP is not 
certificated for use in any service, it can only be used as an 
intentional emitter in a licensed service if that service permits the 
use of uncertificated equipment.

In the second and third cases, you must comply with the relevant 
requirements of Parts 15 and/or 18 for the class of unlicensed operation 
that applies to your situation.  In many cases relevant to the USRP, 
neither Part 15 nor Part 18 will require certification. Generally, 
"kits" and one-off projects require neither certification nor a 
"declaration of comformity"; those requirements typically only come into 
play when a device that operates within the scope of these rules is to 
be offered for sale or distribution in commerce.  The frequency, power, 
spurious emission, and bandwidth limitations applicable to Part 15 and 
Part 18 devices are complicated, and it's no mean feat to determine 
whether a given usage is or is not permissible; do your due diligence 
before you transmit at any measurable power. 

In the final case, of course, you can do whatever you negotiate for from 
the FCC.  STAs are not that hard to obtain, especially if you already 
have a relationship with the FCC. 

If you're trying to develop a commercial product, you should obtain an 
STA to do any free space testing; you'll need to deal with the FCC 
anyway to get the eventual certification, and doing the STA will put the 
OET on notice of your product development, which might possibly 
facilitate the eventual certification of your device for commercial sale 
(or not).  If you're just playing with radio out of personal interest, 
get an amateur radio license and use the amateur allocations, or if your 
particular investigation cannot be conducted on the amateur bands, use 
your amateur radio license as an entry to get an amateur STA.  (The FCC 
may, in some circumstances, waive its usual fees for an application for 
an STA from an amateur licensee.)  If your investigation or experiment 
is such that it can be conducted within the scope of a Part 15 
intentional radiator not requiring certification, then just do it, 
although in that case I still recommend that you get an amateur radio 
license, because it will make your life slightly easier if you do find 
yourself dealing with the Enforcement Bureau.

Regards,

Kelly (AB9RF)