08-06-2013 11:30 PM - edited 08-06-2013 11:32 PM
If I'm reading this correctly, the FCC proposes to limit p2p links to 23 dbi - considerably less than what's currently allowed.
08-06-2013 11:43 PM
33. Antenna Gain. Under Section 15.247, the assumed antenna gain is 6 dBi, with a 1 dB
reduction in power required for every 1 dB that the antenna gain exceeds 6 dBi. For fixed point-to-point
systems, no power reduction is required. Section 15.407 assumes the same antenna gain of 6 dBi, with 1
dB reduction in power required for every 1 dB that gain exceeds 6 dBi. For fixed point-to-point systems,
a 1 dB reduction in power is required for every 1 dB that gain exceeds 23 dBi. The only difference
between the two rule parts is the maximum antenna gain that can be deployed without a penalty in
transmitter power. We propose to apply the more stringent 23 dBi maximum antenna gain that is
currently required under Section 15.407. We believe that using the more stringent antenna gain
requirement will ensure that there is no increase in the potential for interference from unlicensed devices operating under the new combined rule parts.
The Commission brought together all of the principal parties including NTIA, FAA,
industry participants and the FCC’s Enforcement Bureau and Office of Engineering and Technology to
analyze the interference situation. Based on these investigations, the Commission has taken actions to
mitigate the interference situation, including issuing enforcement advisories to heighten users’ awareness
of TDWR interference issues,12 and the Office of Engineering and Technology has placed conditions on
U-NII device certifications to curtail the interference risk. The Commission also has sent enforcement
teams to work with FAA staff in the field, and has taken enforcement actions against operators of U-NII
devices that caused interference to TDWR installations including issuing Letters of Inquiry and Notices of
Apparent Liability for Forfeitures to operators found to be causing interference.13 Most of these
interference cases were caused by devices not certified for operation in the U-NII-2C band, which
includes the 5.6-5.65 GHz band used by the TDWRs. Instead, these devices had been certified for
operation in the U-NII-3 band, either as U-NII devices under Section 15.407 of our rules or as digitally
modulated intentional radiators under Section 15.247 of our rules, and which were operating at high
power levels in elevated locations. The Commission’s investigations found that most U-NII devices are
manufactured to enable operation across a wide range of frequencies, extending down into the 4-GHz
bands and up to almost 6 GHz. In many cases, the interference was caused by third parties modifying
software configurations to enable operation in frequency bands other than those for which the device had been certified but without meeting the technical requirements for operation in those frequency bands. There was also an issue with devices that employed frame based architectures that allowed operators to reconfigure the talk/listen ratio of their devices.
NTIA and the Federal Aviation Administration (FAA) have recently recommended to the Commission
that the 2006 compliance and measurement procedures for DFS be revised to include modified
definitions, technical requirements (e.g., detection bandwidth and pulse repetition interval values), radar
test waveforms, test procedures, and test report guidelines.
In addition, Congress has enacted legislation that addresses unlicensed use of the 5 GHz
band. The Spectrum Act requires the Commission to begin a proceeding to modify Part 15 of the title 47,
Code of Federal Regulations (CFR), to allow unlicensed U-NII devices to operate in the 5.35-5.47 GHz
band (referred to hereinafter as U-NII-2B) no later than 1 year after the date of the enactment of the Act19
if, in consultation with the Assistant Secretary of Commerce (i.e., the NTIA Administrator), it determines
that licensees will be protected by technical solutions and that the primary mission of Federal spectrum
users in the band will not be compromised by the introduction of unlicensed devices in this band.
Ubiquiti Carrier Wireless Admin, Trainer
08-06-2013 11:46 PM
A new Wi-Fi standard—IEEE 802.11ac that is expected to be finalized in the
near future—would allow for wider bandwidth transmissions by devices that would operate over more
than one U-NII band, thus increasing use of the band for broadband services.26 Also, the amount of
contiguous spectrum available for U-NII devices may increase as we, in conjunction with NTIA,
investigate opening the U-NII-2B and U-NII-4 bands to these devices
In particular, we are proposing to align the provisions for operation of
digitally modulated devices in the 5.725-5.85 GHz band, now permitted under Section 15.247 of our
rules,30 with the rules for the U-NII-3 band under Section 15.407. This will expand the U-NII-3 band by
25 megahertz and provide consistent rules across 125 megahertz of spectrum. We also seek comment on
aligning the power limits and permissible location for operations in the U-NII-1 and U-NII-2A bands to
permit the introduction of a new generation of wireless devices in 200 megahertz of contiguous spectrum.
In this NPRM, we also seek comment on modifying Part 15 Subpart E of the
Commission’s rules governing the operation of U-NII devices to make available an additional 195
megahertz of spectrum in the 5.350 – 5.470 GHz (U-NII-2B) and 5.850 – 5.925 GHz (U-NII-4) bands.
This would increase the spectrum available to unlicensed devices in the 5 GHz band by nearly 35 percent
and would represent a significant increase in spectrum available for unlicensed operations.
Ubiquiti Carrier Wireless Admin, Trainer
08-07-2013 05:46 AM
08-08-2013 02:52 PM
Does seem back-asswards doesn't it? Logically, it should have been total EIRP, period. PtP should always have the goal of focusing a signal on one spot the way a higher gain antenna would do. If you reduce the gain of the antenna, it just means you are spreading the signal beamwidth so that it is more likely to interfere with others ... ??? Oh well, that's the way it goes.