Community discussions

MikroTik App
 
yottabit
Member Candidate
Member Candidate
Topic Author
Posts: 198
Joined: Thu Feb 21, 2013 5:56 am

US FCC to Relax Rules in the 5 GHz UNII-1 Band

Tue Apr 01, 2014 5:28 pm

Big news!

Will soon be able to go to full 1000 mW in the 5 GHz UNII-1 band!

http://www.revolutionwifi.net/2014/03/f ... nii-1.html

Hopefully these new rules can be added to the country domain settings for the US in an upcoming RouterOS update. And hopefully most (all?) of the existing hardware can support the higher power in that band.
 
SteveLamb
just joined
Posts: 4
Joined: Fri Apr 08, 2011 5:43 pm

Re: US FCC to Relax Rules in the 5 GHz UNII-1 Band

Wed Apr 09, 2014 12:16 am

Can we get conformation that Mikrotik will be updating their fccIDs to include this band change. If so is there an anticipated time line. This would literally be a game changer for our company.
 
0ldman
Forum Guru
Forum Guru
Posts: 1465
Joined: Thu Jul 27, 2006 5:01 am

Re: US FCC to Relax Rules in the 5 GHz UNII-1 Band

Wed Apr 09, 2014 7:40 am

Just a little bit I read says that MT has been operating in the ISM portion of the 5GHz band, not UNII certified.

The ISM hardware will no longer be allowed to be manufactured in the US after a year (I think that's right) and no longer imported after 2 years.
 
fgoldstein
Frequent Visitor
Frequent Visitor
Posts: 65
Joined: Thu Aug 19, 2010 4:50 am

Re: US FCC to Relax Rules in the 5 GHz UNII-1 Band

Mon Apr 21, 2014 10:29 pm

It is definitely time for MikroTik to get "U-NII" 15.407 approval in the US. The ISM-band rules (15.247)for broadband use are being deleted. They have one year (from the official effective date of the rule, probably in June) to get any more 15.247 approvals and another year to sell out stock. The new U-NII (15.407) rules for the same frequencies are being liberalized to resemble the ISM rules, but with some new restrictions, and new type approval will be needed before anything can go down into the 5150-5250 band.

Summary of the changes: Some rules have been tightened to reduce the chance of interference to radar, especially TDWR, but more spectrum has been opened to outdoor use. Note that this was not the final word on the FCC's docket 13-49. It focused on the U-NII-1 band (5150-5250) and U-NII-3 band (5725-5825). The proposed new U-NII-2B and U-NII-4 bands were not addressed. Those are more controversial and await a later R&O.

The 5725-5850 ISM band (Rules Part 15.247) was essentially merged with
U-NII-3 (15.407). The upper band edge of U-NII-3 was moved from 5825 to
5850 to match ISM. Wideband digital operation was removed from ISM,
limiting 15.247 operation on that band to frequency hopping spread
spectrum (narrowband) and the FH portion of hybrid devices. As of one
year after publication in the Federal Register, no new 15.247 wideband
devices will be type-approved for that band, and sale and importation
must stop in two years. Existing devices may continue to be used.

The WISP community did dodge a bullet here, as the new U-NII-3 rules are
closer to the ISM rules than to the old U-NII rules. In particular, the
proposal to limit EIRP of fixed point-to-point links to +53 dBm, the old
U-NII-3 limit which did not apply to ISM, was not adopted. Fixed
point-to-point U-NII-3 operation can still have unlimited antenna gain
with 1 watt transmitter power. Some of the credit goes to WISPA, who is
acknowledged in the Order. Power spectral density rules
were also modified to a favorable outcome. The old U-NII-3 rules
required 20 MHz bandwidth for full power. The new rules are closer to
ISM's, requiring a minimum 6 dB bandwidth of only 500 kHz for full
power. Point to multipoint EIRP is still capped at +36 dBm. So there
is little lost in the new rules, although the new type approval
procedures will be just a bit harder than the old ones.

The second major area of change was the U-NII-1 band, 5150-5250. This
had been limited to indoor only use with a +17 dBm power limit.
Globalstar, the low-earth-orbit satellite, is the primary user here,
using it for backhaul (not handset) uplinks, and while LEOsats in
general did not catch on as the FCC had expected when the old rule was
written in 1997, Globalstar did not want its background noise level to
be impacted. A deal was worked out that is still pretty good.

Under the new rules, outdoor operation is now allowed, and the rules there are based on the old U-NII-3 rules (which were not widely used). So the power limit is 1 watt, and access points may have up to 6 dB gain without lowering power (i.e., a +36 dBm EIRP cap). Point-to-point links may have up to 23 dB gain without lowering power (i.e., a +53 dBm EIRP cap). "Mobile and portable client devices" in that band are capped at 250 mW (+24) with 6 dB gain (i.e., a +30 dBm EIRP cap). There is no explicit rule for fixed client devices, like WISP CPE, so it appears to be treated as portable, as the definition of "fixed, point-to-point" explicitly excludes "point-to-multipoint systems". This could be rather limiting and might merit a little ex parte discussion with the Friendly Candy Company. The rule was written with WiFi access points (is CableWiFi messing up the spectrum in your neighborhood too?) in mind.

In order to protect Globalstar, outdoor U-NII-1 access points have to be
sure their EIRP more than 30 degrees above the horizon does not exceed
+21 dBm. This seems pretty easy, unless say you're doing a steep
point-to-point shot upwards at a skycraper. Another rule requires
operators who install more than 1000 outdoor U-NII-1 APs to notify (by
letter) the FCC and acknowledge that they will take corrective action if
it does interfere with licensed (satellite) users. So the average WISP won't be
affected but big cable-style or city-wide deployments could have to notify.

Minor changes were made for U-NII-2 (5250-5350 and 5470-5725), were DFS
is required. The radar test procedures were slightly changed. A very
useful rule change is that DFS hopping no longer has to be uniform. The
radio can operate on a selected first-choice frequency until it detects
radar, and then hop to a selected alternative, etc. So band planning is
now legally possible on the DFS bands. Note that proposals to create a
geographic database for U-NII frequencies (like TVWS), as an alternative
to radar sensing, were rejected.

Type approval for all U-NII equipment now requires that it be locked to US specifications, so that users can't just turn off DFS and use DFS frequencies, or operate outside of authorized US frequencies. The licensed 4.9 GHz public safety band, for instance, will require a different SKU or license key, not just retuning of an unlicensed radio. Manufacturers can choose the method for enforcing how only approved software upgrades can be installed. Certain upgrades of existing gear will be permitted for two years without meeting all of the new rules, but not afterwards.

MikroTik radios will need new approval, and the more restrictive US-locked software, in order to stay on sale in the US after two years, let alone operate on the newly-authorized outdoor frequencies. This should be a good incentive to finally get U-NII approval. Note that it is possible to get U-NII approval for non-DFS frequencies without DFS, if the radio can't be tuned to DFS frequencies (U-NII-2). But my guess is that the DFS-Radar in RouterOS is pretty close to what's needed anyway.
 
User avatar
colebert
Member Candidate
Member Candidate
Posts: 187
Joined: Sun Jul 19, 2009 3:45 am

Re: US FCC to Relax Rules in the 5 GHz UNII-1 Band

Tue Apr 22, 2014 4:36 pm

Thank God they didn't eliminate the unlimited antenna gain in 5.8GHz. My entire network (9 hops) is based on MetalHPs/XR5s & 10ft waveguide fed dishes.
 
User avatar
Hammy
Forum Veteran
Forum Veteran
Posts: 776
Joined: Fri May 28, 2004 5:53 pm
Location: DeKalb, IL
Contact:

Re: US FCC to Relax Rules in the 5 GHz UNII-1 Band

Sat Jun 21, 2014 1:23 pm

Bueller? Bueller? Bueller?


Sent from my iPad using Tapatalk HD
 
fgoldstein
Frequent Visitor
Frequent Visitor
Posts: 65
Joined: Thu Aug 19, 2010 4:50 am

Petitions pending to fix problems in the U-NII rules

Wed Jul 23, 2014 10:39 pm

After the new U-NII rules came out, vendors began to look at the requirements for type acceptance, and discovered a problem that, if not fixed, potentially guts the benefits of the new rules and, because the old rules expire, makes the situation far worse than the status quo. The problem concerns the specific requirement for out-of-band emissions allowed under U-NII rules (15.407), which are computed differently from the old ISM-band rules (15.249).

To simplify it, 15.249 says that out-of-band emissions usually have to be 30 dB below the desired emissions. It's a relative value ("dBr"). There are other out-of-band limits too, but this is the key one. So if you look at the spectrum trace of a typical 20 MHz signal, it's down by 30 dB soon enough (sometimes even within 5 MHz). If your transmitter power is 1 watt (the limit, +30 dBm) and antenna gain is +25 dB, EIRP is +55 and out-of-band EIRP can be +25, or +12 dBm/MHz. That's how MikroTik radios are approved. And everybody else who supports 5725-5850 also uses 15.247 approval, even if they have 15.407 (U-NII) for the DFS bands, because 15.247 grants more capabilities and is easier to meet.

The new rules do away with 15.249 for new equipment but nominally allow unlimited EIRP under 15.407 from 5725-5850. The problem is that 15.407's spec for out-of-band is not relative, like 15.249. Nor is it a fixed transmitter power. It's a fixed EIRP. The signal has to be at -17 dBm/MHz at band edge and -27 dBm/MHz at 10 MHz from band edge.

This was never a problem for U-NII-II (5250-5725) because the EIRP limit there was +30 dBm and +17 dBm/MHz, so meeting -17 dBm/MHz was only 34 dB. Not a huge deal. And it wasn't a huge deal for omni access points, because the PtMP limit was +36 dBm EIRP, and thus a 40 dB ratio was achievable with, say, 10 MHz guard band.

But getting past 40 dB is really hard. If you are using a 23 dB antenna and a +30 dBm transmitter, you're at +53, the PtP limit for the new U-NII-1 band, and of course there is no EIRP limit for PtP above 5725. But wait... +53 dB EIRP = +40 dB/MHz = +57 dBr against -17 and 67 dBr against -27 (10 MHz away). No, MikroTik can't meet that. Nor can brand U, brand C, brand M, or anyone else. And if you have a radio approved for a certain antenna gain, it might be out-of-approval with a higher-gain antenna -- which is silly, since high gain antennas focus the out-of-band as well as in-band signals, reducing actual interference.

There are two petitions now before the FCC to fix this. WISPA's simply calls for the old 15.247 rules to remain in effect, so nobody needs to transition to 15.407. Mimosa's calls for 15.409 to be modified so that out-of-band is allowed to go up by 1 dB for every dB of antenna gain above 6 dB. That equates to 40 dBr worst case, PtP, for U-NII-1 and U-NII-3.

You can go to the FCC's Electronic Comment Filing System (you know, the one that was totally clobbered by last week's NN filings :-) ) and go to (ET) docket 13-49. You can see the WISPA and Mimosa petitions, as well as filings from Cambium and others in agreement. My comment is there (under the name of Interisle Consulting Group, my firm), supporting both Cambium and WISPA. Some of you may want to weigh in. I don't know of a date for closing Comments; this is still just a petition, not a rulemaking.

Who is online

Users browsing this forum: kymo2, sinisa and 13 guests