Posts Tagged ‘630m’
U.S. LF Bands – Rulemaking Ruminations (Part 2)
(...cont'd)
* TWO: We need more technical showings this time, with as many solid
details as possible. I hope the Part 5 licensees are prepared to crunch
numbers, but those of us who only monitored are also able to contribute.
(Much more on this in future correspondence, I expect.) In par. 169. the FCC enquires: "to meet our goal of providing for the coexistence of amateur services and PLC systems in these bands, we seek detailed comment on the technical characteristics of both the PLC systems and the amateur stations.
This information will allow us to set an appropriate separation distance."
The very next sentence, though, I recognize as a somewhat worrisome bit of FCC-speak: "Although the Commission in the WRC-07 NPRM inquired into the technical rules and methods that would assure coexistence, commenters provided little in the way of concrete information." Read that as said with a slightly scolding tone, but with a facial expression that says they're keeping an open mind.
The utilities, IMO, provided no concrete technical information at all. ARRL
cited the 1985 NTIA study on which the 1 W EIRP and 1 km separation idea is based, but the FCC is concerned whether that's still valid. Well, one would hope that any changes made to PLCs over the past 30 years would be toward making the system more robust, not more vulnerable to evildoers, accidents, and natural disasters, but this could prove an area of contention. That may be something the big guys have to fight out; I don't know how much we as individual licensees or observers can contribute. But there ARE other technical matters the FCC needs and wants to know, which we may be able to furnish.
For instance, what sort of PLC signal levels have we actually experienced in the proposed bands? How serious were their impact on licensed activity, and how have PLCs been coped with in actual operation? Also at paragraphs 171, 178, and 178, the FCC is asking for some really fundamental, crucial data.
Namely: What sort of power levels have the Part 5 licensees actually
radiated, and at what actual separations from transmission lines? What
maximum size should an amateur antenna be, and--the biggie, in my view--what is the efficiency of both "typical" and potential amateur antenna systems?
(The Commission would like us to include information from Canadian and
European hams on these issues as well. Details of amateur practice in the
rest of the world could be very helpful in formulating rules here.)
Those operators who have the capability of measuring their true field
strength are in an especially excellent position to help quantify current
practice. Those who can't do that, but are able to measure their ground
losses accurately, can make reasonable calculations to show the maximum
efficiency possible with antennas of various heights. That's likely
preferable to doing it all in NEC modeling, since not all such software is
really good at predicting ground system losses, especially at LF. I'll
gladly offer my own ground system's resistance numbers to anyone who wants to do the math, for instance, as its 32 radials of 104 to 135 ft length in 15 mS/m soil are probably representative of a fairly decent ground for
antennas up to 100 feet high...and I'll be doing another set of readings
very soon, which can include measurements at 2200 m this year in addition to the runs I routinely do at 1750 m.
* THREE: At 172, the FCC observes: "If we were to adopt our proposal to
permit amateur operations only when separated by a specified distance from transmission lines, when a new transmission line is built close by an
amateur station, the station either would have to relocate farther away from the transmission line or cease operating." Scary, huh. But they go on to ask: "How should our rules address the potential for new transmission lines to be constructed closer than the specified distance to pre-existing amateur stations? We do not want to inhibit the ability of either PLC systems or amateur services to grow and expand without imposing unnecessary burdens on either. Is it possible for utilities to refrain from geographically expanding their PLC operations within the relatively small portion of the 9-490 kHz band that we are making available for amateur operations, and is this something utilities would do on their own accord, given the Part 15 status of PLC systems? Should our rules explicitly prohibit utilities from deploying new PLC systems in these bands?"
My answer: yes, please. Look back at par. 26, in the WRC-07 R&O section
where the Commission explains their basis for adding the 2200 m allocation:
"We intend to structure these service rules to promote shared use of the
band among amateurs and PLC systems. Amateurs will not be able to use their allocation status to force unlicensed PLC operations out of the band, and utilities will have no cause to abandon or incur large costs to modify
existing PLC systems." Read that again: "Amateurs will not be able to use
their allocation status to force unlicensed PLC operations out of the band."
That's the reality of the matter, and yet I think it also works in our
favor.
So far as I know, this situation is unique in the history of radio regulation. I can't think of another example where an incumbent, but unlicensed and unallocated, user of radio spectrum has been afforded such protection from any allocated and licensed service. However, most of us who commented in the 2013 proceeding DID AGREE with the Commission that PLC technology has been a special case for a long time, and most recognized that acceptance of its existence was the only way to move the discussion off dead center and get to the point where we are now.
But I maintain this coin has two sides. If we in a licensed, allocated service are willing to accept that we cannot displace existing PLCs now or in the future, then it is ONLY FAIR that the unlicensed, unallocated users should not be able to displace the licensed users, either, now or in the future. Otherwise, it is not truly sharing.
The only way I can see to guarantee protection to licensed users, comparable to what the unlicensed ones will have, is to incorporate within Part 15 a prohibition on any changes in power, transmission mode, and route of existing PLC systems, or installation of new ones, within a reasonable band centered on the new amateur allocations. That achieves the stated goal of not displacing existing systems or burdening the utlities by forcing any changes to them, while only removing two small slices of spectrum from consideration for future installations. That seems an entirely reasonable compromise to me.
Your comments are welcome--and essential!
73
John Davis
You can view comments as well as file your own, via the link from this page:
http://apps.fcc.gov/ecfs/proceeding/view?name=15-99
* TWO: We need more technical showings this time, with as many solid
details as possible. I hope the Part 5 licensees are prepared to crunch
numbers, but those of us who only monitored are also able to contribute.
(Much more on this in future correspondence, I expect.) In par. 169. the FCC enquires: "to meet our goal of providing for the coexistence of amateur services and PLC systems in these bands, we seek detailed comment on the technical characteristics of both the PLC systems and the amateur stations.
This information will allow us to set an appropriate separation distance."
The very next sentence, though, I recognize as a somewhat worrisome bit of FCC-speak: "Although the Commission in the WRC-07 NPRM inquired into the technical rules and methods that would assure coexistence, commenters provided little in the way of concrete information." Read that as said with a slightly scolding tone, but with a facial expression that says they're keeping an open mind.
The utilities, IMO, provided no concrete technical information at all. ARRL
cited the 1985 NTIA study on which the 1 W EIRP and 1 km separation idea is based, but the FCC is concerned whether that's still valid. Well, one would hope that any changes made to PLCs over the past 30 years would be toward making the system more robust, not more vulnerable to evildoers, accidents, and natural disasters, but this could prove an area of contention. That may be something the big guys have to fight out; I don't know how much we as individual licensees or observers can contribute. But there ARE other technical matters the FCC needs and wants to know, which we may be able to furnish.
For instance, what sort of PLC signal levels have we actually experienced in the proposed bands? How serious were their impact on licensed activity, and how have PLCs been coped with in actual operation? Also at paragraphs 171, 178, and 178, the FCC is asking for some really fundamental, crucial data.
Namely: What sort of power levels have the Part 5 licensees actually
radiated, and at what actual separations from transmission lines? What
maximum size should an amateur antenna be, and--the biggie, in my view--what is the efficiency of both "typical" and potential amateur antenna systems?
(The Commission would like us to include information from Canadian and
European hams on these issues as well. Details of amateur practice in the
rest of the world could be very helpful in formulating rules here.)
Those operators who have the capability of measuring their true field
strength are in an especially excellent position to help quantify current
practice. Those who can't do that, but are able to measure their ground
losses accurately, can make reasonable calculations to show the maximum
efficiency possible with antennas of various heights. That's likely
preferable to doing it all in NEC modeling, since not all such software is
really good at predicting ground system losses, especially at LF. I'll
gladly offer my own ground system's resistance numbers to anyone who wants to do the math, for instance, as its 32 radials of 104 to 135 ft length in 15 mS/m soil are probably representative of a fairly decent ground for
antennas up to 100 feet high...and I'll be doing another set of readings
very soon, which can include measurements at 2200 m this year in addition to the runs I routinely do at 1750 m.
* THREE: At 172, the FCC observes: "If we were to adopt our proposal to
permit amateur operations only when separated by a specified distance from transmission lines, when a new transmission line is built close by an
amateur station, the station either would have to relocate farther away from the transmission line or cease operating." Scary, huh. But they go on to ask: "How should our rules address the potential for new transmission lines to be constructed closer than the specified distance to pre-existing amateur stations? We do not want to inhibit the ability of either PLC systems or amateur services to grow and expand without imposing unnecessary burdens on either. Is it possible for utilities to refrain from geographically expanding their PLC operations within the relatively small portion of the 9-490 kHz band that we are making available for amateur operations, and is this something utilities would do on their own accord, given the Part 15 status of PLC systems? Should our rules explicitly prohibit utilities from deploying new PLC systems in these bands?"
My answer: yes, please. Look back at par. 26, in the WRC-07 R&O section
where the Commission explains their basis for adding the 2200 m allocation:
"We intend to structure these service rules to promote shared use of the
band among amateurs and PLC systems. Amateurs will not be able to use their allocation status to force unlicensed PLC operations out of the band, and utilities will have no cause to abandon or incur large costs to modify
existing PLC systems." Read that again: "Amateurs will not be able to use
their allocation status to force unlicensed PLC operations out of the band."
That's the reality of the matter, and yet I think it also works in our
favor.
So far as I know, this situation is unique in the history of radio regulation. I can't think of another example where an incumbent, but unlicensed and unallocated, user of radio spectrum has been afforded such protection from any allocated and licensed service. However, most of us who commented in the 2013 proceeding DID AGREE with the Commission that PLC technology has been a special case for a long time, and most recognized that acceptance of its existence was the only way to move the discussion off dead center and get to the point where we are now.
But I maintain this coin has two sides. If we in a licensed, allocated service are willing to accept that we cannot displace existing PLCs now or in the future, then it is ONLY FAIR that the unlicensed, unallocated users should not be able to displace the licensed users, either, now or in the future. Otherwise, it is not truly sharing.
The only way I can see to guarantee protection to licensed users, comparable to what the unlicensed ones will have, is to incorporate within Part 15 a prohibition on any changes in power, transmission mode, and route of existing PLC systems, or installation of new ones, within a reasonable band centered on the new amateur allocations. That achieves the stated goal of not displacing existing systems or burdening the utlities by forcing any changes to them, while only removing two small slices of spectrum from consideration for future installations. That seems an entirely reasonable compromise to me.
Your comments are welcome--and essential!
73
John Davis
You can view comments as well as file your own, via the link from this page:
http://apps.fcc.gov/ecfs/proceeding/view?name=15-99
U.S. LF Bands – Rulemaking Ruminations (Part 1)
John Davis of the Longwave Club of America has been doing a good job of keeping us informed of the present 2200/630m application status for U.S. amateurs. It seems that although the NPRM has not yet been published in the Federal Register, the FCC website is open for comments on this issue. I would urge all amateurs with an interest in LF operation to file comments that address the FCC's Notice Of Inquiry (NOI), particularly if you have been operating an experimental station. As well, Canadian LFers operating on either band should consider filing comments as well, describing your system and overall operating results. You can read a full review of the FCC's concerns in three of my earlier blogs:
http://ve7sl.blogspot.ca/2015/04/lf-mf-next-step-for-us-amateurs-part-1.html
http://ve7sl.blogspot.ca/2015/05/lf-mf-next-step-for-us-amateurs-part-2.html
http://ve7sl.blogspot.ca/2015/05/lf-mf-next-step-for-us-amateurs-part-3.html
John's latest information points out what he believes are three crucial points that deserve serious thought. As he indicates, if we don't 'get it right' the first time, it might be very difficult to make any changes after the fact. Please give serious thought to John's information and to filing your own comments at the link provided.
In John's own words:
Rulemaking Ruminations
This is probably a good time to get discussion reactivated on the MF and LF ham proposals. Although I continue not to see publication of the NPRM in the Federal Register as yet, the FCC EFCS Web page for the proceeding is open and accepting filings. Until FR publication, we won't know the closing dates for comments and replies, but you can see what's already been going on at:
http://apps.fcc.gov/ecfs/proceeding/view?name=15-99
While I've been awfully tied up with other things recently, my reading of
the proposal thus far brings to mind three points I believe we earnestly
need to address with the Commission. This proceeding will set the exact US
rules for 2200 m, and very probably also 630 m, so it behooves us to make
the best case we can, now, right up front. If the initial rules are too
restrictive on amateur activity, it could be very difficult and time
consuming to get them changed. Here are my present concerns.
* ONE: In paragraph 168, the FCC states that in addition to separation
distances and power limits, "we propose to limit amateur stations to
operations at fixed locations only to ensure that this separation distance
can be maintained reliably." That's stricter than it may first sound. The
FCC's actual proposed wording for § 97.303(g)(1), for both 2200 and 630 m,
is: "Amateur stations are restricted to use at permanent fixed locations."
Permanent fixed locations. That goes way beyond my suggestion that mobile operation be prohibited. It precludes temporary fixed operation, such as Field Day activities, or tests of ground characteristics for future potential antenna sites, or other legitimate short-term experiments. In my view, this is needlessly restrictive, and could also open the door to more rigid coordination requirements that might paint us into a corner, figuratively and literally, at our original QTHes.
We need to make a strong case that hams are able to identify electric
transmission lines and maintain 1 km separation (or other specified
distance) from them. This further relates to comments the FCC seeks in par. 176: "Amateur licensees will have to determine the location of transmission lines in their vicinity to determine if they are permitted to operate stations using these frequency bands. .... High voltage transmission lines are typically attached to large steel towers that are easy to identity.
However, lower voltage transmission lines are typically attached to wooden poles. Although the wooden poles used for transmission lines are usually taller than the wooden poles used for distribution lines, we recognize that distinguishing the two types may not always be straightforward. We seek comment on whether amateur licensees will be able to identify the transmission lines in their locality."
Obviously, just glancing around a proposed operating site and saying "nope, I don't see a transmission line" is not enough. But I think we're smart enough to do responsible surveys of all lines within a mile or so in all directions, identify any substation locations, and determine which sets of poles have customer connections (practically the definition of distribution lines) and which don't (therefore assumed to be transmission lines). We need to convince the FCC that we can tell the difference.
... to be cont'd
LF / MF – Next Step For U.S. Amateurs (Part 3)
Continuing with the important sections of NPRM (FCC 15-50) affecting the future of LF/MF assignments in the U.S.A. ...
174.
We also seek comment on the applicability of IEEE 1613-2009 – IEEE Standard Environmental and Testing Requirements for Communications Networking Devices Installed in Electric Power Substations ... ARRL claims that PLC systems complying with IEEE-1613 “would virtually guarantee that there would be no interaction between amateur stations and PLC systems,” and that compliance with the standard has been required by the Commission’s since 2002. As background, the Commission’s rules require that PLC systems conform to engineering standards promulgated by the Commission and adhere to industry approved standards designed to enhance the use of PLC systems. Is compliance with this IEEE standard required by the Commission’s rules (i.e. is this an industry approved standard designed to enhance the use of PLC systems)? Would compliance of PLC systems with this standard facilitate the sharing of these bands between amateur stations and PLC systems? Are there PLC systems deployed that do not comply with this standard?
Would compliance with this standard obviate the need for amateur stations to maintain a specific separation distance from transmission lines?
175.
We recognize that the separation distance required for PLC systems and amateur stations to coexist will depend on the power at which the amateur stations are permitted to transmit. We propose that amateur stations in the 135.7-137.8 kHz band be limited to a maximum EIRP of 1 W, as is required by footnote RR 5.67A, and which we adopted in the WRC-07 R&O. Is this EIRP limit appropriate for facilitating sharing between PLC systems and amateur stations? For the 472-479 kHz band, we propose to adopt transmitted power limits consistent with RR 5.80A. Amateur stations will be limited to an EIRP of 1 W in the portion of Alaska within 800 km of the Russian Federation and will be permitted to transmit at up to 5 W EIRP elsewhere. Is this EIRP limit appropriate for PLC systems and amateur stations to share this band? Should amateur stations be required to reduce their EIRP below 5 W when close to transmission lines and at what distances? We seek comment on these proposals.
176.
We also seek comment on the practical application of a separation distance requirement, and, specifically, what resources and information amateur radio operators will need to comply with our rules. Amateur licensees will have to determine the location of transmission lines in their vicinity to determine if they are permitted to operate stations using these frequency bands. The amateur licensees will need to differentiate transmission lines from the electric distribution lines that connect distribution substations to customer or house wiring. High voltage transmission lines are typically attached to large steel towers that are easy to identity. However, lower voltage transmission lines are typically attached to wooden poles. Although the wooden poles used for transmission lines are usually taller than the wooden poles used for distribution lines, we recognize that distinguishing the two types may not always be straightforward. We seek comment on whether amateur licensees will be able to identify the transmission lines in their locality. If amateur licensees are not able to reliably identify transmission lines, should we require amateurs or ARRL to affirmatively verify the locations of transmission lines with utilities or UTC before an amateur station begins transmitting?
178.
Lastly, we seek comment on additional service and operational rules that would be appropriate for amateur operations in these bands. According to ARRL, the tallest antenna that should reasonably be considered for an amateur station is 200 feet, because antennas with greater heights would
be required to obtain prior FAA approval and have to comply with FAA painting and lighting requirements. We note that adopting a maximum antenna height for amateur stations in these bands will aid in sharing of the spectrum with PLC systems by limiting the number of transmission lines that would potentially be in direct line-of-sight of amateur station antennas. We seek comment on what maximum antenna height, if any, we should adopt for amateur stations in these bands.
179.
We also invite comment on whether to adopt transmitter power limits for amateur stations, in addition to the EIRP limits we are proposing. If so, we seek comment on what the power limits should be. We observe that, in the 2002 Amateur Radio NPRM, the Commission proposed to limit the maximum transmitter power in the 135.7-137.8 kHz band to 100 W PEP because of the possible difficulty of measuring the EIRP of an amateur station in this frequency range. Also, in 1998, ARRL submitted data for the 135.7-137.8 kHz band showing that relatively short antennas can only produce ranges of EIRP that are well below the ITU’s 1 W EIRP limit (i.e., 10-40 mW for a 100 foot antenna and 1-4 mW for a 50 foot antenna) with a transmitter power output of 200 W PEP. The Commission did not consider either power limit at that time, because, as noted above, it decided not to adopt an allocation for amateur operations in this band. Given that we have adopted such an allocation in the WRC-07 R&O above, do either the 2002 Amateur Radio NPRM or ARRL’s 1998 study provide a basis for determining transmitter power limits now? Should these transmitter power limits vary depending on antenna height – e.g. we could allow a 200 W PEP limit for antenna heights not exceeding 30.5 meters while permitting only 100 W PEP for taller antennas. Should the transmitter power limits differ between the 135.7-137.8 kHz band and the 472-479 kHz bands?
180.
In response to the WRC-07 NPRM, commenters addressed a number of steps that could facilitate amateur use of the 135.7-137.8 kHz band. Amateur operator John H. Davis (Davis) proposed that no amateur station should be automatically controlled to ensure that the amateur operator is able to quickly terminate transmissions if necessary. Davis also suggested that it may be appropriate to also prohibit software-driven modes that determine their own operating frequency without human intervention.
Should we adopt Davis’s suggestions? ARRL’s states that there is no rationale for limiting the occupied bandwidth in the 135.7-137.8 kHz band to less than the full 2.1 kilohertz, and that a stricter limit would not be conducive to experimentation with narrowband data emission modes in the future. Should we adopt any bandwidth limitation for either of the frequency bands? In the WRC-07 NPRM, the Commission requested comment on whether it should limit operating privileges in the 135.7-137.8 kHz band, e.g., to Amateur Extra Class licensees. None of the commenters believe that such a restriction would better facilitate Amateur/PLC sharing of the band. In particular, we note that ARRL states that it would be consistent with Commission policy to make this frequency band available to Amateur Extra, Advanced, and General Class licensees. Should we limit operating privileges for these bands in accordance with ARRL’s statement? Should we propose to authorize CW (international Morse code telegraphy), RTTY (narrow-band direct-printing telegraphy), and data emissions throughout the 630 and 2200 meter bands as we did for our 2200 meter band proposal in 2002? We also seek comment on amending Section 97.3 by adding definitions for the terms effective radiated power, isotropically radiated power, and LF.
181.
Other Allocated Uses. Other radio services use the 135.7-137.8 kHz band. In the U.S. Table, the 130-160 kHz band is allocated to the fixed service (FS) and maritime mobile service (MMS) on a primary basis for Federal and non-Federal use ... The 126.7-141.7 kHz band is also used to track tagged salmon in the Pacific watershed. We seek comment on whether we need
to adopt exclusion zones or use other methods to protect these Federal uses of the band. Should we delete the unused non-Federal allocations from this band? To be consistent with the International Table, we also propose to require that amateur fixed stations operating in the 2200 meter band not cause harmful interference to stations in the FS and MMS that are authorized by other nations and require that these amateur stations take any and all corrective action, if harmful interference is reported to us. We seek comment on these proposals.
It would appear that the nature of enquiry is extensive but it is the next step needed before the LF / MF bands will become a reality in the U.S.
Following publication of the NPRM in the Federal Register (see daily updates here to see when it appears), stakeholders will have 60 days to make comments. Comments can be written or posted via their online comment page once it is opened. A thirty-day reply-to-comments period then ensues.
One source that I have read indicates that there is usually about 12-18 months before NPRM publication and rule enactment, should there be no major stumbling blocks. Whenever the final decision to implement comes will depend on how the enquiry proceeds.
I would urge all those interested in seeing these band become a reality to file comments when the opportunity becomes available, following the Federal Register posting. Comments could include your opinions on power levels, methods of stating / measuring power levels, restrictions on operating near power transmission lines, modes allowed, etc. It is particularly important for U.S. experimental stations to file a detailed report on their operations, including accurate descriptions of antenna systems and transmitter details. As well, I would urge Canadian amateurs that have had experience operating on either of these two bands, to file comments regarding your experiences, with particular emphasis on the lack of interference caused to PLC signals and the lack of interference caused by PLC signals to your own operation. Rest assured that U.S. power authorities will be putting their resources ($$) into one last lobby for as many restrictions as possible and it is not in our interest for the NPRM comments to be one-sided in their favor.
Lets all hope for a swift outcome to something that has been taking far too long.
LF / MF – Next Step For U.S. Amateurs (Part 2)
With the release this week of NPRM (FCC 15-50), U.S. amateurs have moved one small-step closer to seeing the 2200m and 630m bands become a thing of reality.
The NPRM seeks input on a number of questions that rulemakers are still pondering when it comes to implementation of the new bands. Stakeholders are requested to submit comments on a number of issues addressed in the document and have 60 days to do so once the document has been published in the Federal Register which is updated daily.
Following submission of comments, a number of options still remain open for FCC rulemakers and I rather suspect, from the vast scope of the NPRM's inquiry, that the process could drag on for some length of time yet. Take solace in the fact that the NPRM is indeed a necessary step in the right direction and shows that the proposals are moving forward, finally!
The major focus of the NPRM appears to be centered around determining appropriate levels of power and the viability of amateurs coexisting on the frequencies shared with Power Line Carrier (PLC) systems. Indeed the major stumbling block, at least as far as 2200m is concerned, has always been the strong objection from power authorities that amateur signals will interfere with their control signals. PLC interference as well as possible interference to the Maritime Mobile Service (MMS) is also cited as a concern for the 630m proposal. One might argue that lumping these two bands together in a single NPRM is the best way to go while others might say that chance of success would be much better by treating them separately ... time will eventually tell.
Getting into more detail, the NPRM commentary specifically affecting our LF/MF interests, address the following critical points (and present stumbling blocks):
167.
Service Rules for the 135.7-137.8 kHz and 472-479 kHz bands. We are proposing service rules for the amateur service in the 135.7-137.8 kHz and 472-479 kHz bands with the principal goal of enabling sharing of this spectrum among licensed amateur stations and unlicensed PLC systems.
As the demand for radio spectrum has continued to increase, we have sought to make more efficient use of spectrum by providing for sharing of frequency bands for multiple purposes.While we recognize the importance of PLC systems to the functioning of the electric power grid, we also believe that there are benefits to providing amateurs access to these bands, including providing amateurs with new opportunities for experimentation. Moreover PLC systems and the expected amateur use of these bands have characteristics which make coexistence possible. PLC systems are limited to use on transmissions lines and, consequently, are not present in most residential neighborhoods where amateur licensees live.
The amateur service is expected to use the band mainly for experimental purposes and not for routine and widespread communications activities common in other bands. These attributes give us confidence that,
along with appropriate technical rules, amateur stations can harmoniously operate on the same frequency bands as PLC systems.
168.
The cornerstone of the technical rules we are proposing is physical separation between amateur stations and the transmission lines upon which PLC systems may be present. We propose that amateur stations be permitted to operate in these bands when separated from transmission lines by a specified distance. Such a separation, in conjunction with limits on the amateur stations’ transmitted EIRP and antenna heights, will enable PLC systems and amateur stations to coexist in these bands. In addition, we propose to limit amateur stations to operations at fixed locations only to ensure that this separation distance can be maintained reliably. We seek comment on this overall framework.
169.
In order to develop the necessary and appropriate service rules to meet our goal of providing for the coexistence of amateur services and PLC systems in these bands, we seek detailed comment on the technical characteristics of both the PLC systems and the amateur stations. This information will allow us to set an appropriate separation distance. Although the Commission in the WRC-07 NPRM inquired into the technical rules and methods that would assure coexistence, commenters provided little in the way of concrete information. ARRL submitted a technical analysis based on an NTIA technical report supporting an assertion that PLC systems in the 135.7-137.8 KHz band will be sufficiently protected from amateur stations transmitting at an EIRP of 1 W with a separation distance of 1 km from the transmission lines carrying the PLC signals. However, this NTIA technical report is from 1985 and therefore may not account for any subsequent developments.
170.
To assist us in determining the optimal separation distance, we invite commenters to submit information on the technical characteristics of PLC systems that are currently being operated by utilities or likely to be deployed in the future. How tolerant are these PLC systems of signals received from other stations transmitting in the same band? What electric field strength at the location of a transmission line will cause a PLC system operating on that line to malfunction? What types of malfunctions would the electric power grid experience from electrical interference? How many PLC systems are currently operating in the 2200 and 630 Meter bands? Can these existing PLC systems be modified and could new PLC systems be designed to operate in other portions of the 9-490 kHz band, thus avoiding co-channel operation with amateur services? At what power do these PLC systems operate and how long are the transmission lines over which they send signals? At what voltage level do the transmission lines upon which these PLC systems are deployed operate and how does the PLC systems’ tolerance of other signals depend on the voltage level? What electric field strengths are produced in the vicinity of transmission lines by the PLC signals travelling over the transmission lines?
171.
We likewise invite information on the technical characteristics of amateur stations that are likely to be deployed or have operated under experimental licenses in these two bands. What electric field strength generated by PLC systems operating on transmission lines would impede the operation of
amateur stations? A study conducted on a PLC system operating at 1 W at 152 kHz found that the PLC system generated an electric field strengths of 20 dbμV/m at 1 km. Would a signal with this field strength interfere with the operation of amateur stations? Given that high-voltage transmission lines generate a significant level of noise at this frequency range, how close to high-voltage transmission lines can amateur stations realistically operate? In recent years amateur stations have operated in these bands
under experimental licenses with most licenses permitting powers of between 1 to 20 watts ERP. How close did these amateur stations operate to transmission lines? Did any of these amateur stations receive
signals from PLC systems operating on transmission lines? Do the experiences of amateur stations and utilities in other countries and along the United States border with Canada yield any useful information?
172.
If we were to adopt our proposal to permit amateur operations only when separated by a specified distance from transmission lines, when a new transmission line is built close by an amateur station, the station either would have to relocate farther away from the transmission line or cease
operating. How should our rules address the potential for new transmission lines to be constructed closer than the specified distance to pre-existing amateur stations? We do not want to inhibit the ability of either PLC systems or amateur services to grow and expand without imposing unnecessary burdens on either. Is it possible for utilities to refrain from geographically expanding their PLC operations within the relatively small portion of the 9-490 kHz band that we are making available for amateur operations, and is this something utilities would do on their own accord, given the Part 15 status of PLC systems? Should our rules explicitly prohibit utilities from deploying new PLC systems in these bands?
....to be cont'd
The NPRM seeks input on a number of questions that rulemakers are still pondering when it comes to implementation of the new bands. Stakeholders are requested to submit comments on a number of issues addressed in the document and have 60 days to do so once the document has been published in the Federal Register which is updated daily.
Following submission of comments, a number of options still remain open for FCC rulemakers and I rather suspect, from the vast scope of the NPRM's inquiry, that the process could drag on for some length of time yet. Take solace in the fact that the NPRM is indeed a necessary step in the right direction and shows that the proposals are moving forward, finally!
The major focus of the NPRM appears to be centered around determining appropriate levels of power and the viability of amateurs coexisting on the frequencies shared with Power Line Carrier (PLC) systems. Indeed the major stumbling block, at least as far as 2200m is concerned, has always been the strong objection from power authorities that amateur signals will interfere with their control signals. PLC interference as well as possible interference to the Maritime Mobile Service (MMS) is also cited as a concern for the 630m proposal. One might argue that lumping these two bands together in a single NPRM is the best way to go while others might say that chance of success would be much better by treating them separately ... time will eventually tell.
Getting into more detail, the NPRM commentary specifically affecting our LF/MF interests, address the following critical points (and present stumbling blocks):
167.
Service Rules for the 135.7-137.8 kHz and 472-479 kHz bands. We are proposing service rules for the amateur service in the 135.7-137.8 kHz and 472-479 kHz bands with the principal goal of enabling sharing of this spectrum among licensed amateur stations and unlicensed PLC systems.
As the demand for radio spectrum has continued to increase, we have sought to make more efficient use of spectrum by providing for sharing of frequency bands for multiple purposes.While we recognize the importance of PLC systems to the functioning of the electric power grid, we also believe that there are benefits to providing amateurs access to these bands, including providing amateurs with new opportunities for experimentation. Moreover PLC systems and the expected amateur use of these bands have characteristics which make coexistence possible. PLC systems are limited to use on transmissions lines and, consequently, are not present in most residential neighborhoods where amateur licensees live.
The amateur service is expected to use the band mainly for experimental purposes and not for routine and widespread communications activities common in other bands. These attributes give us confidence that,
along with appropriate technical rules, amateur stations can harmoniously operate on the same frequency bands as PLC systems.
168.
The cornerstone of the technical rules we are proposing is physical separation between amateur stations and the transmission lines upon which PLC systems may be present. We propose that amateur stations be permitted to operate in these bands when separated from transmission lines by a specified distance. Such a separation, in conjunction with limits on the amateur stations’ transmitted EIRP and antenna heights, will enable PLC systems and amateur stations to coexist in these bands. In addition, we propose to limit amateur stations to operations at fixed locations only to ensure that this separation distance can be maintained reliably. We seek comment on this overall framework.
169.
In order to develop the necessary and appropriate service rules to meet our goal of providing for the coexistence of amateur services and PLC systems in these bands, we seek detailed comment on the technical characteristics of both the PLC systems and the amateur stations. This information will allow us to set an appropriate separation distance. Although the Commission in the WRC-07 NPRM inquired into the technical rules and methods that would assure coexistence, commenters provided little in the way of concrete information. ARRL submitted a technical analysis based on an NTIA technical report supporting an assertion that PLC systems in the 135.7-137.8 KHz band will be sufficiently protected from amateur stations transmitting at an EIRP of 1 W with a separation distance of 1 km from the transmission lines carrying the PLC signals. However, this NTIA technical report is from 1985 and therefore may not account for any subsequent developments.
170.
To assist us in determining the optimal separation distance, we invite commenters to submit information on the technical characteristics of PLC systems that are currently being operated by utilities or likely to be deployed in the future. How tolerant are these PLC systems of signals received from other stations transmitting in the same band? What electric field strength at the location of a transmission line will cause a PLC system operating on that line to malfunction? What types of malfunctions would the electric power grid experience from electrical interference? How many PLC systems are currently operating in the 2200 and 630 Meter bands? Can these existing PLC systems be modified and could new PLC systems be designed to operate in other portions of the 9-490 kHz band, thus avoiding co-channel operation with amateur services? At what power do these PLC systems operate and how long are the transmission lines over which they send signals? At what voltage level do the transmission lines upon which these PLC systems are deployed operate and how does the PLC systems’ tolerance of other signals depend on the voltage level? What electric field strengths are produced in the vicinity of transmission lines by the PLC signals travelling over the transmission lines?
171.
We likewise invite information on the technical characteristics of amateur stations that are likely to be deployed or have operated under experimental licenses in these two bands. What electric field strength generated by PLC systems operating on transmission lines would impede the operation of
amateur stations? A study conducted on a PLC system operating at 1 W at 152 kHz found that the PLC system generated an electric field strengths of 20 dbμV/m at 1 km. Would a signal with this field strength interfere with the operation of amateur stations? Given that high-voltage transmission lines generate a significant level of noise at this frequency range, how close to high-voltage transmission lines can amateur stations realistically operate? In recent years amateur stations have operated in these bands
under experimental licenses with most licenses permitting powers of between 1 to 20 watts ERP. How close did these amateur stations operate to transmission lines? Did any of these amateur stations receive
signals from PLC systems operating on transmission lines? Do the experiences of amateur stations and utilities in other countries and along the United States border with Canada yield any useful information?
172.
If we were to adopt our proposal to permit amateur operations only when separated by a specified distance from transmission lines, when a new transmission line is built close by an amateur station, the station either would have to relocate farther away from the transmission line or cease
operating. How should our rules address the potential for new transmission lines to be constructed closer than the specified distance to pre-existing amateur stations? We do not want to inhibit the ability of either PLC systems or amateur services to grow and expand without imposing unnecessary burdens on either. Is it possible for utilities to refrain from geographically expanding their PLC operations within the relatively small portion of the 9-490 kHz band that we are making available for amateur operations, and is this something utilities would do on their own accord, given the Part 15 status of PLC systems? Should our rules explicitly prohibit utilities from deploying new PLC systems in these bands?
....to be cont'd
LF / MF – Next Step For U.S. Amateurs (Part 1)
The ARRL's 600 Meter Experiment Coordinator, Fritz Raab (W1FR) recently released a statement urging that the program be renewed. According to Raab, all of the WD2XSH licences will expire in August. Citing a quarterly report prepared by John Langbridge (KB5NJD) and Warren Ziegler (K2ORS), two very active participants in the program, Raab says that the program has demonstrated that the Amateur Radio community is interested in MF operation.
“Amateurs with ordinary facilities can use the band; exotic antennas are not required,” the report said, adding “QSOs from 500 to 1000 miles are routinely achieved, and longer distances are possible.”
As described in the ARRL News, "The FCC has yet to act on the ARRL’s 2012 Petition for Rulemaking asking it to create a domestic Amateur Radio allocation at 472-479 kHz, known variously as 600 meters and 630 meters. Delegates to the 2012 World Radiocommunication Conference (WRC-12), approved a 7-kilohertz-wide secondary Amateur Radio allocation at 472-479 kHz, with a power limit of 5 W EIRP (or 1 W EIRP, depending on location). Radio amateurs in Canada and in several other countries already have allocations there. Canadian 630 meter operators held a cross-band event on February 14, listening on 160 and 80 meters for US stations."
“Following the WRC-12 decision to create an amateur 630-meter band, most of us expected the FCC to approve access for US amateurs,” Raab’s report said. “Had this happened, there would not be further need for the WD2XSH license. Over 2 years have passed since the ARRL petitioned the FCC to consider this band, and the FCC does not appear to be in any hurry to do so.”
As amateurs here in Canada have discovered, the U.S. experimenters have demonstrated reliable regional ground-wave communications is readily achievable in this part of the spectrum, making reliance on ionospheric conditions a none-issue. The report also addressed the question of interference, a possible long-standing reason cited in reasons for not giving LF bands to amateurs.
" ... in 179,000 hours of operation, “there has not been one complaint of harmful interference from either other radio services or utility power-line communications.” The FCC cited concerns about possible interference to utility power-line carrier (PLC) systems in deciding not to adopt its own 2002 proposal for an LF allocation in the vicinity of 137 kHz. The WD2XSH status report noted that the radiated power from some WD2XSH stations and of other experimental stations working at 630 meters, “is well above the 5 W EIRP of the WRC-12 authorisation.”
Raab goes on to suggest that the ARRL "should have a continued presence in our quest for a 630 meter amateur band” and recommended renewing the license.
MF operators in Canada are also anxiously awaiting the appearance of their southern-neighbours, which would likely result in a large spike in new Canadian activity.
The experimental program has done the heavy lifting and demonstrated that amateurs can operate in this part of the spectrum, at moderate to high power levels, without causing interference. Remember that even though the 5W EIRP limit seems low, due to antenna inefficiencies at this frequencies, transmitters typical are required to generate several hundreds of watts to reach the 5W EIRP limitations.
With all of the above in mind, it seems that indeed the next steps to making these two bands available to U.S. amateurs has drawn one-step closer to reality.
On April 26th, two weeks after Raab's somewhat downcast report, the FCC announced the NPRM (Notice of Proposed Rulememaking) which included the proposals for both 2200m and 630m. NPRM's provided stakeholders the opportunity to file comments as well as provide the filer (FCC in this case) a final opportunity to gather information which will help them form future policy ... in this case, what the rules for the new bands might look like, should they proceed with implementation.
A closer look at the NPRM will be of interest to amateurs who have been waiting for some action ...
(... cont'd)
“Amateurs with ordinary facilities can use the band; exotic antennas are not required,” the report said, adding “QSOs from 500 to 1000 miles are routinely achieved, and longer distances are possible.”
As described in the ARRL News, "The FCC has yet to act on the ARRL’s 2012 Petition for Rulemaking asking it to create a domestic Amateur Radio allocation at 472-479 kHz, known variously as 600 meters and 630 meters. Delegates to the 2012 World Radiocommunication Conference (WRC-12), approved a 7-kilohertz-wide secondary Amateur Radio allocation at 472-479 kHz, with a power limit of 5 W EIRP (or 1 W EIRP, depending on location). Radio amateurs in Canada and in several other countries already have allocations there. Canadian 630 meter operators held a cross-band event on February 14, listening on 160 and 80 meters for US stations."
“Following the WRC-12 decision to create an amateur 630-meter band, most of us expected the FCC to approve access for US amateurs,” Raab’s report said. “Had this happened, there would not be further need for the WD2XSH license. Over 2 years have passed since the ARRL petitioned the FCC to consider this band, and the FCC does not appear to be in any hurry to do so.”
As amateurs here in Canada have discovered, the U.S. experimenters have demonstrated reliable regional ground-wave communications is readily achievable in this part of the spectrum, making reliance on ionospheric conditions a none-issue. The report also addressed the question of interference, a possible long-standing reason cited in reasons for not giving LF bands to amateurs.
" ... in 179,000 hours of operation, “there has not been one complaint of harmful interference from either other radio services or utility power-line communications.” The FCC cited concerns about possible interference to utility power-line carrier (PLC) systems in deciding not to adopt its own 2002 proposal for an LF allocation in the vicinity of 137 kHz. The WD2XSH status report noted that the radiated power from some WD2XSH stations and of other experimental stations working at 630 meters, “is well above the 5 W EIRP of the WRC-12 authorisation.”
Raab goes on to suggest that the ARRL "should have a continued presence in our quest for a 630 meter amateur band” and recommended renewing the license.
MF operators in Canada are also anxiously awaiting the appearance of their southern-neighbours, which would likely result in a large spike in new Canadian activity.
The experimental program has done the heavy lifting and demonstrated that amateurs can operate in this part of the spectrum, at moderate to high power levels, without causing interference. Remember that even though the 5W EIRP limit seems low, due to antenna inefficiencies at this frequencies, transmitters typical are required to generate several hundreds of watts to reach the 5W EIRP limitations.
With all of the above in mind, it seems that indeed the next steps to making these two bands available to U.S. amateurs has drawn one-step closer to reality.
On April 26th, two weeks after Raab's somewhat downcast report, the FCC announced the NPRM (Notice of Proposed Rulememaking) which included the proposals for both 2200m and 630m. NPRM's provided stakeholders the opportunity to file comments as well as provide the filer (FCC in this case) a final opportunity to gather information which will help them form future policy ... in this case, what the rules for the new bands might look like, should they proceed with implementation.
A closer look at the NPRM will be of interest to amateurs who have been waiting for some action ...
(... cont'd)
A Versatile 630m Antenna
Mark, VA7MM, had come up with a nicely-designed antenna that will serve as his main 630m radiator. Not only that but it can be used on 10m, 15m and 30m and 160m as well!
The antenna consists of a mini-flat top dipole, with three resonant dipole legs all terminating at a common feedpoint.
This can be used directly on any of the three high bands. Shorting the end of the coaxial cable, dropping vertically down from the feeedpoint, the dipole feedline becomes the vertical element of a top-loaded 630m 'T' antenna, 100' in the air.
With suitable loading coils and appropriate switching, the 'T' will also be used on 160m, making the versatile antenna work on five different bands ... a nice demonstration of basic antenna principles put into real practice!
‘OO’ Oshawa NDB
You may recall my blog describing the recent reception of the Oshawa Municipal Airport's NDB, "OO" on 391KHz. The Nav Canada beacon maintenance man, Alex, (VE3GOP) also a Yahoo Group NDBlist member was able to pay a visit to the beacon on Friday and confirm the reported output power is indeed just 7.5 watts! He even snapped a picture of the power meter ... talk about service!
Little "OO" has also been reported in Europe by none other than Roelof, PAØRDT, while using one of his own small active whips. I think this illustrates the remarkable propagation that can, and often does, take place below the broadcast band, even with a less than optimum antenna system ... good news for those planning a 630m backyard antenna installation!
courtesy: A. Wiecek, VE3GOP |
Little "OO" has also been reported in Europe by none other than Roelof, PAØRDT, while using one of his own small active whips. I think this illustrates the remarkable propagation that can, and often does, take place below the broadcast band, even with a less than optimum antenna system ... good news for those planning a 630m backyard antenna installation!