Sorry for the OT, but this does effect us all in the US.
The FCC has invited public comment on a Petition for Rule Making (RM-11715)
that would make a significant portion of the 10.0 to 10.5 GHz band available
for wireless broadband services. The Petition by Mimosa Networks Inc proposes
a band plan for 10.0 to 10.5 GHz that, it says, would protect frequencies most
often used by radio amateurs. The petition hinges on FCC adoption of rule
changes that would put the 10 GHz band under Subpart Z of the Commission’s
Part 90 rules. Subpart Z currently sets out regulations governing wireless
licensing, technical standards, and operational standards in the 3650 to 3700
MHz band.
I've made my comments on this, and would invite other hams to do so. I feel
I'm uniquely qualified to see this from both side as I owned a WISP before.
http://mimosa.co/support-our-petition.html is the link mimosa networks has on
how to comment. I'd encourage you to comment on this, as it will negatively
affect the amateur radio allocation on the most popular microwave band.
Feel free to steal from my comments below:
Comments on RM-11715 Petition for Rulemaking from Mimosa Networks
regarding the 10.0 to 10.5 GHz band.
I am uniquely qualified to comment on this petition as both a licensed
Amateur Radio operator (callsign KB9MCI), and former owner of a Wireless
Internet Service Provider, Illiana Internet LLC from 2000-2006. Currently I
work as Consulting Engineer in the Cellular and Service Provider space. I
have built and operated many amateur radio microwave stations in the 3CM (10
GHz) band.
Wireless Internet Service Providers (WISPs) present themselves as a group
providing Internet to the rural and underserved communities of the USA. To an
extent this is true, however their services are not a substitute for fiber and
wire line carriers. WISP’s are typically a small business, lacking the
capital and skilled engineers needed for day-to-day operation of a multi-site
wireless network. There is little incentive to design with good RF
engineering practices, as most WISP’s lack the ability to hire competent RF
engineers, and supply them with the tools they would need (Spectrum analyzer,
test equipment, etc.).
This lack of RF engineering knowledge leads to inevitable interference
between competing operators, and other users of the ISM and UNI bands. As
interference goes up, power and antenna size invariable increases (even
exceeding the EIRP FCC rules) to maintain service to their customers. This
cannot be allowed to happen in a band shared with weak signal users such as
the Amateur Radio Service.
I am in favor of more spectrum for WISP’s and ideally this would be sub 7
GHz, however if it must be shared spectrum, it needs to be shared with users
that can tolerate a higher noise floor. Weak signal services such as amateur
radio or GPS satellite should not share with such use. Spectrum should be
aligned with international users as well in my opinion; a 10GHz band use under
the Mimosa proposal would be incompatible with this.
The requirements in the 10.0 to 10.5 GHz band as proposed allow a
non-restricted contention based protocol. This should not be permitted in any
case. The amateur radio use of this band is based on such contention-based
protocols (i.e. listening before transmitting). This will encourage WISP
users of this band to run hotter systems to “talk” over competing systems not
unlike what has happened in the ISM and UNI bands. This need for a restricted
contention-based protocol must be retained in any case.
DFS is proposed to avoid co-channel operation with only radar systems.
This excludes the amateur use of these bands. Further threshold is -64 dBm,
which is well above level amateur systems operate at. Amateur use of the 10
GHz band is not “strong signal” fixed operations as point-to-point microwave
use is. Rather, Amateur use is characterized by weak signals and “pushing the
envelope” of RF path link budget. Amateurs may employ CW (A1A), SSB (J3E), FM
(F3E) and other emissions at these frequencies.
DFS needs to be a requirement for not only radar systems, but amateur
systems as well. Even with DFS as a requirement the proliferation of cheap
non-carrier grade WISP equipment from foreign vendors has the potential to be
“unlocked” with DFS and even the proposed protected bands at 10.350-10.370 and
10.450-10.500 GHz being illegally used by untrained operators. Further, most
equipment can be “hacked” to use such restricted channels.
This last point is not to be dismissed, as there have been numerous
actions by the FCC of 5.4 GHz interference from WISP’s to TDWR RADAR.
(
http://www.fcc.gov/encyclopedia/weather-radar-interference-enforcement)
Others commenting in favor of this NPRM have been the recipient of Notices
of Liability and Fines for repeated violations of the requirements to operate
legally in the 5.4 GHz band (ex. EB-09-SJ-0014 – Aeronet Wireless Broadband,
San Juan, PR). What assurance can these operators give the commission and
the amateur radio community that they will not do this again? If this NPRM
is implemented and such interference effects amateur stations it would be
almost impossible for the commission to enforce, as amateur stations are not
fixed or as critical as TDWR RADAR stations are. This would be an
incompatible use.
In 10 GHz amateur operation using narrow bandwidth useful signals may be
below the -174 dBm/hz common minimum discernible signal noise floor,
especially in amateur satellite service, or in Earth Moon Earth (EME) where
signals are reflected off the moon. Further for DFS to work, these narrow
band signals would need to be detected by a receiver with a 20 MHz receive
bandwidth. In these wide band commodity receivers an amateur radio signal at
-130 dBm would not be detected even in the absence of signal. As DFS is not
required to act on a signal less than -64 dBm most amateur radio communication
use would not trigger it. Even more so in the amateur satellite service from
10.450-10.500 GHz, severe interference would be caused by normal operations by
the WISP radios raising the effective noise floor.
An amateur satellite receiver has a wide band pre-amplifier, such strong
signals even 20 MHz removed from the intended signal would require expensive
and high signal loss pre-selective filters. Would Mimosa networks intend to
pay for these filters for every amateur radio receiver? What of current
satellite receivers in orbit that cannot be retrofitted?
The proposed strong signal use adjacent to the Amateur Satellite service
at 10.450-10.500 GHz by channel 21 is without technical precedent. A receiver
on a satellite would hear every strong broadband transmitter in its footprint
as it passes over the US. This interference would cause amateur radio
operators far removed from the transmitter to be unable to communicate through
satellites they had previously been able to communicate through. I would
refer to the LightSquared Petition to the FCC for use of ancillary terrestrial
component equipment in its spectrum and the impact on GPS receivers.
Based on these facts I would ask the Commission to deny the Mimosa petition.
73's
--
Bryan Fields
727-409-1194 - Voice
727-214-2508 - Fax
http://bryanfields.net