US no-license for USRP info?

Posted by Michael Dickens (Guest)on 2008-06-26 20:07

Looking at < >:"The USRP is sold as test equipment, which has no licensing requirements."

Can someone with experience in this area please explain to me the relevant -specific- portion(s) of the US law/code regarding the USRP? Please do not say "Part 15" since that's a large chunk of writing. I'm looking for (example) "15.103 (c)" as a specific portion (which, btw, is interesting but IMHO not applicable to the USRP). Thanks in advance! - MLD

Re: US no-license for USRP info?

Posted by Dave Killion (Guest) on 2008-06-29 04:34

I am not a lawyer (IANAL). The following comments deal with US laws and policies as I understand them.

The basic idea as to how USRP's can be sold to an unlicensed user is that they are sold as "Radio Test Parts" - that is, you assemble it yourself into a functional receiver/transmitter. Furthermore, it needs software (that Matt doesn't provide) in order to create a functional radio system. That's how you legally obtain the USRP.

Reception of radio transmissions is a protected activity in the US - that is, you can implicitly do it unless specifically told not to - in the US (where the USRP is made and sold) with the exception of cellular telephone bands (that's the "not to" part). The USRP daughter boards that transmit and receive on those protected frequencies have a filter for those frequencies by default. But since the USRP is an international product (used all over the world), the block is not difficult to bypass for users in other countries that are not restricted or use different bands.

Transmission is restricted by both frequency and power depending on what license you have.

For instance, Title 47 Part 95 covers all "Personal Communications", which includes the frequency band used by CB radios (CFR, 95.401), as well as the Family Radio Service (CFR, Part 95.191-95.194). Products sold that use these two bands are reviewed by the FCC to ensure they don't exceed power and frequency restrictions for those bands. There are etiquette rules to follow using these bands, but they are otherwise unrestricted. There are also additional PC bands (GMRS, for instance) that require a license which is not difficult to obtain. Great page with lots of info for these services can be found here:

If you used your USRP on these bands and stayed within the legal power levels, I doubt there would be a real problem. Technically, the USRP has not been reviewed to transmit on those bands, but... if you're following the power and frequency guidelines, I'd imagine you'd not be hassled.

If you have obtained a HAM radio license, then you'll legally have access to a wide range of bands and considerably high power systems. Part 97 covers all of that. If you get a license, you'll know what bands and power you'll be permitted - it's part of the test. :) Part 97 data is here:

Most any other bands not covered in the Personal or HAM bands are generally restricted from use unless specifically licensed.

I'm sorry, I know I'm not being terribly specific like you asked,'re not asking very specific questions. Obtaining the USRP is perfectly legal. What you intend to do with it is up to you. Depending on the frequency, power levels, and potential disruption to other radio devices (a big no-no in the US), different regulations will apply.

I hope this helps some,


Dave Killion, CISSP

Contributing Author, Security Power Tools


Re: US no-license for USRP info?

Posted by Kelly Martin (Guest)on 2008-06-29 05:45

It is not legal to use "homebrew" equipment to transmit on any of the Part 95 personal communications services (e.g. FRS, GMRS, CB, MURS) or in fact in any service other than the amateur radio service. Any transmitter to be used in any licensed service (other than the amateur service), whether licensed-by-rule or individually licensed, must have had its manufacturing design certified by the FCC, and any modifications thereto made consistent with the rather complicated rules in Part 2. However, as the FCC does not actively regulate the Part 95 services (that is, they typically only investigate complaints regarding activities in these bands when they create problems in other services, or have implications beyond merely being annoying to other licensees), you can probably get away with transmitting in these services with uncertificated radios. Just make sure your spurious emissions are under control; if you are splattering into a band allocated to another service, you might find yourself the subject of an interference complaint, and if the investigation determines that you're using an uncertificated radio, you will get slapped with an "unauthorized operation"citation and quite possibly a forfeiture.

I imagine most USRP uses in the US that involve transmit are conducted either within the limits for Part 15 intentional radiators, or within the scope of the amateur radio service. Note that Part 15 allows low power operations in quite a lot of spectrum; for example, you can transmit in at least part of the FM broadcast band within the limits of Part 15 as long as you keep your power low enough. Unfortunately, Part 15 is very very complicated and figuring out if a particular use or purpose is permitted under it, and if so under what conditions, can be quite challenging.

It is likely the case that any USRP-based application would be unable to be certified due to the FCC's requirement for certification that the programming of a software-defined radio must be locked so as to prevent the end user from changing it. It's an open question (as far as I know) whether you can bundle a USRP, some daughterboards, and a software load together and sell that, but I strongly suspect the answer to that is a no, as such a bundle would amount to a transmitter under FCC regs (if a TX daughterboard is present) and would have to be certified before it could be sold, and because of the USRP's ready reprogrammability will necessarily fail the lockdown rules imposed by section 2.944.


On Sat, Jun 28, 2008 at 9:33 PM, Dave Killion <>

Re: US no-license for USRP info?

Posted by Daniel O'Connor (Guest)on 2008-06-30 03:11
On Mon, 30 Jun 2008, Clark Pope wrote:
> Does anyone know what the export situation is for the USRP? Seems to
> me even in receive only mode their must be some objective criterion
> (tune range, speed, bandwidth, etc.) that determines whether usrp can
> or cannot be exported? Also, since the usrp is being used in
> government/military applications, why doesn't ITAR apply to it?

ISTR it comes down to digitiser speed & bit width and computing power.

The USRP isn't particularly great in either regard (no offense intended :) so I don't think it would be an issue..

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