On Monday, the FCC formally adopted a First Report and Order (FCC 14-30) in ET Docket 13-49, revision of Part 15 U-NII rules. The actual R&O text was released later in the week. For the most part, it came out well for WISPs. 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 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.
Key changes that were announced: 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. (Cambium too, while its former parent Motorola Solutions was on the wrong side.) 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. 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 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 or operate outside of authorized frequencies. 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. So it seems to me that UBNT and Cambium gear should be all good to go on the new frequencies pretty quickly, as they are U-NII approved. I don't think MikroTik is (it's apparently ISM, not DFS approved here, unless they've recently gotten it), so their radios will need new approval, and the more restrictive software, in order to stay on sale here after two years, let alone operate on the newly-authorized outdoor frequencies. All told the rules are a positive outcome. Congratulations to everyone who helped influence the FCC. -- Fred R. Goldstein k1io fred "at" interisle.net Interisle Consulting Group +1 617 795 2701 _______________________________________________ Wireless mailing list [email protected] http://lists.wispa.org/mailman/listinfo/wireless
