FCC RM-10051
Comments of the ARRL
Before the
FEDERAL COMMUNICATIONS COMMISSION
Washington, DC 20554
In the Matter of )
)
Petition for Rule Making of SAVI ) RM-10051
Technology, Inc.; Amendment of )
Part 15 to Permit Broader Data )
Transmission Capabilities )
To: The Commission
COMMENTS OF ARRL, THE NATIONAL ASSOCIATION FOR AMATEUR RADIO
IN RESPONSE TO PETITION FOR RULE MAKING
ARRL, The National Association For Amateur Radio ("ARRL",
also known as the American Radio Relay League, Incorporated), by
counsel and pursuant to Section 1.405(a) of the Commission's Rules
[47 C.F.R. §1.405(a)] hereby respectfully submits its comments in
response to the Petition for Rule Making (the Petition) filed on
or about November 22, 2000 by SAVI Technology, Inc. (SAVI). The
Petition was placed on Public Notice January 30, 2001 by the
Commission (Report No. 2462). These comments are therefore timely
filed. The Petition seeks changes in the Commission's Part 15
rules governing unlicensed, periodic, intentional radiators so as
to permit increased duty cycles and permitted field strengths for
radio frequency identification (RFID) systems. In response to the
requested changes, ARRL states as follows:
1. This petition is another in a long series of rulemaking
petitions in which the Commission is asked by manufacturers of
unlicensed Radio Frequency (RF) devices to liberalize the rules
regarding permitted field strengths for such devices, in bands
allocated to the Amateur Service. The instant Petition follows the
classic format whereby the petitioner: (1) touts the alleged
utility to consumers of the technology used on an unlicensed
basis; (2) asserts that the Commission's Part 15 regulations are
insufficiently liberal to accommodate the universe of possible
features of the technology; (3) makes no reference to the
interference potential to licensed radio services in the band of
choice (which band was typically selected by the manufacturer ab
initio without reference to interference potential to licensed
services, or the performance of the device in the presence of
licensed radio services); and then (4) requests the rule change
without technical justification therefor. ARRL suggests that this
petition, like its progenitors, is unsupported by interference
studies, and therefore contains insufficient reasons in support of
the action requested to justify the institution of a rulemaking
proceeding. Accordingly, it should be dismissed pursuant to
Section 1.407 of the Commission's Rules.
2. As ARRL has noted numerous times in the past, the
Commission has jurisdictional limitations on its ability to
liberalize Part 15 regulations. Unlicensed Part 15 devices have no
allocation status, internationally or domestically. These devices
are permitted on an "at-sufferance" basis: they must not cause
interference to licensed radio services, and they must tolerate
interference received from licensed radio services in the same
bands. The Communications Act of 1934 is devoid of any authority
to allow unlicensed devices with substantial interference
potential; such devices must be licensed. The only authority
granted to the Commission to permit unlicensed transmitting
devices under the Act is with respect to radio control and
citizen's radio service facilities, 47 U.S.C. §307(e)1. The Act
also permits the Commission to regulate the interference potential
of RF devices by "reasonable regulation", 47 U.S.C. §302. This
the Commission has done by permitting operation of such devices in
bands allocated, on a primary basis, to one or more licensed radio
services, but only where the operation of the unlicensed devices
has been determined to be unlikely to cause interference to the
licensed radio services. In this case, SAVI has made no showing
that unlicensed RFID devices at the requested higher field
strength levels and radically increased duty cycles proposed could
be operated on an itinerant basis without undue risk of harmful
interference to the Amateur Service. Neither has the Petitioner
shown any reason why the extremely high field strengths of 110,000
microvolts per meter measured at 3 meters is required to
communicate over paths of 100 meters.
3. In order to invoke Communications Act jurisdiction to
amend the Part 15 rules as requested by SAVI, the Commission must
make a specific finding that the SAVI devices under the proposed
new rules would not cause interference to licensed radio services.
SAVI has configured the operation of its RFID tag transmitters in
the 420-450 MHz band (specifically centered at 433.9 MHz)2 and
proposes to operate them at field strengths of 110,000 uV/m, with
duty cycles up to two minutes at a time, and only a ten-second
silent period between transmissions. The current Section 15.231(e)
provisions for periodic radiators, however, permit field strengths
of less than 5,000 uV/m at that frequency (measured at 3 meters),
with duty cycles of less than one second, assuming a silent period
between transmissions of at least 30 times the duration of the
transmission.
4. Thus, in order to justify the requested rule change, SAVI
would have to affirmatively demonstrate to the Commission, and the
Commission would have to affirmatively determine, that the
proposed change in the rules for RFID tags, allowing a 30 dB
increase in field strength, accompanied by a radical increase in
duty cycle of these periodic radiators, would not result in
interference to existing services. Furthermore, with respect to
control transmissions, SAVI states at page 5 of its Petition that
periodic transmissions for control purposes (which under present
Section 15.231(a)(3) are limited to not more than one second per
hour), should be restricted only by a ten percent duty cycle
requirement with no periodic transmission restriction. SAVI
asserts that the modified rules "would allow for full 128 kilobyte
data transmission without increasing the possibility of additional
interference since the range of 100 meters would be maintained as
would the overall power and field strength limitations."
5. In any case, the premises of the Petition are flawed.
First of all, ARRL strongly disagrees with SAVI's suggestion that
field strengths of 110,000 uV/m for these devices would limit the
range of SAVI's transmissions to 100 meters. Signals of that
magnitude would provide reasonable communications at ranges well
in excess of 1 kM, even with insensitive receivers and low-gain
antennas. The potential for interference to sensitive amateur
radio receivers, which in the 433 MHz band utilize very high gain
antennas, is extreme. The entire method by which SAVI determined
that a signal level of 110,000 uV/m is permitted is a serious
misinterpretation of the language of Section 15.35(c). That
section stipulates that the maximum amount of time over which a
pulse train can be averaged is 0.1 seconds. If this averaging is
applied to a 120-second transmission, or a 0.1 second pulse within
any transmission, the resultant averaging is a factor of 100
percent, meaning that no averaging is applied at all under those
circumstances. Because these devices transmit data, SAVI also
incorrectly starts with the table in Section 15.231(e); but that
error is moot anyway because averaging cannot be applied to a
pulse train whose length is greater than or e qual to 0.1 seconds
in any case.
6. At page 5 of the Petition, SAVI contends that its control
polling is limited to one second per hour. This is true only to
the extent that SAVI wishes to utilize the field strengths
permitted in the Section 15.231(b) table. However, Section 15.231
stipulates that:
(e) Intentional radiators may operate at a periodic rate
exceeding that specified in paragraph (a) and may be employed for
any type of operation, including operation prohibited in paragraph
(a), provided that the intentional radiator complies with the
provisions of paragraphs (b) through (d) of this Section, except
that the field strength table in paragraph (a) is replaced by
...[a replacement table]
The replacement table would permit a field strength of 4,398.7
uV/m at 433.92 MHz. This should be adequate for communication out
to approximately 300 meters if a reasonably sensitive receiver is
employed. The limitation claimed by SAVI, therefore, is reasonably
addressed by present Section 15.231 rules.
7. SAVI's premise that the current rules would require 30
minutes of clock time to download 128 kilobytes of data is
incorrect. The provisions of Section 15.231(c) stipulate that the
bandwidth shall not exceed 0.25% of the operating frequency. At
433.92 MHz, the permitted bandwidth would be greater than 1 MHz.
8. The proposed rules attached to the Petition do not track
the contentions in the Petition. The rules would completely
eliminate the averaging issues discussed relative to Section
15.35, and would simply permit commercial and industrial devices
to transmit up to 120 seconds continuously, and to emit RF energy
during that entire period at levels up to 110,000 uV/m. This is
many orders of magnitude greater than what is currently permitted.
Signal levels of that order could be heard for kilometers, or
more, with even low-gain antennas. Existing periodic emitters
function reasonably well within the existing provisions of Section
15.231(a) and 15.231(e); there is no demonstration in the Petition
that 120 seconds of transmission, with but a 10-second off-time,3
at 110,000 uV/m measured at 3 meters is necessary or appropriate.
The existing provisions of Section 15.231 serve adequately for a
communications range of 100 meters. If SAVI cannot use modulation
and encoding techniques that would allow them to get data
throughput they need to communicate 128 kilobytes of data in a
reasonable time, they should manufacture equipment under the
several other sections of Part 15 that do not have the limits the
Commission intended for periodic radiators, which were configured
to limit interference.
9. In a broader sense, the Commission is presently without
empirical data concerning ambient noise levels in bands used by
Part 15 devices. It therefore is unable to determine, much less
predict, whether the permitted field strengths for Part 15 devices
are adequate, overly limited, or overly liberal. Limited anecdotal
study by ARRL technical staff of noise levels from unlicensed
devices in certain metropolitan areas indicate that man-made RF
noise is substantially increasing. ARRL has offered to contribute
by participation of volunteers in a planned study of noise levels
proposed by the Commission's Technological Advisory Council (TAC).
The TAC formed a Noise Subcommittee, which has reported to the
Commission that:
Based on the trends in new wireless devices and systems, the
subcommittee concluded that the noise environment may degrade
significantly in the near future and therefore it warrants
significant additional focus at this time.4
The TAC stated that "we could potentially be entering a period of
rapid degradation of the noise environment" and that this
degradation "could impact the reliability of current systems and
the viability of future communications systems."5 Premised on
these forecasts, the Commission must be extremely careful in
evaluating rulemaking petitions proposing substantial departures
from present Part 15 rules. It must make evaluations of those
proposals based on technical compatibility studies. Absent such in
the instant petition, it can only be concluded that the Petition
is incomplete and fails to justify the relief requested, and it
must therefore be denied. 10. The Amateur Service makes
extensive use of the 420-450 MHz band. There are approximately
6,300 FM voice repeaters in the United States in the band, and at
least that number of fixed control and auxiliary point-to-point
links there as well. The locations and frequencies are not
published by the licensees or the volunteer coordinators. The 420-
450 MHz band has experienced significant growth in recent years.
Amateur radio operation in the 420-450 MHz band is not based on
fixed transmitter operation. Amateur transmitter locations and
signal paths are unpredictable in that band. It is extremely
popular among radio Amateurs, and there are many thousands of
Amateur stations which utilize extremely sensitive receivers for
weak-signal transmissions at 432-433 MHz. Because RFID tags are
itinerant and mobile, there is absolutely no chance whatsoever
that interference between Amateur stations and RFID tags could be
mitigated once the devices are deployed. The interference
potential of these devices is thus completely unpredictable, and
cannot be remedied easily. While there is some flexibility in
amateur operation such that interfering signals compliant with the
periodic rates permitted by the current Section 15.231 rules can
be tolerated without harmful interference, the field strengths and
duty cycles proposed by SAVI are completely unreasonable and would
undoubtedly seriously disrupt Amateur communications in one of the
most popular of the Amateur Service allocations.
Therefore, the foregoing considered, ARRL, the National
Association for Amateur Radio, respectfully requests that this
Petition be immediately denied or dismissed, pursuant to Section
1.407 of the Commission's Rules.
Respectfully submitted,
ARRL, THE NATIONAL ASSOCIATION
FOR AMATEUR RADIO
225 Main Street
Newington, CT 06111
By: ____________________________
Christopher D. Imlay
Its General Counsel
BOOTH, FRERET, IMLAY & TEPPER, P.C.
5101 Wisconsin Avenue, NW, Suite 307
Washington, DC 20016-4120
(202) 686-9600
Page last modified: 11:25 AM, 06 Mar 2001 ET
Page author: awextra@arrl.org
Copyright © 2001, American Radio Relay League, Inc. All Rights Reserved.
