I am starting to separate the non 70cm specific areas of this document. They will be moved to:
How Rules Change
First, here is a recent example of how the rules change as we do, from March
The petition asks the FCC to allow those amateurs who are presently using a Motorola narrowband (12.5 kHz) digital land mobile system -- commercially marketed as MotoTRBO -- to be used legally. Because of some restrictions in the Part 97 rules, the TDMA repeaters (which are multiple-time-slot devices) are legal, but the mobiles and portables are not because the emissions used ….
The KA9FLX repeater in Chicago, IL was the first Mototrbo Amateur Radio Repeater. It was put on the air in 2008. At the time of this petition, there are more that a dozen Mototro repeaters in service on amateur frequencies. Since then, over 90 repeaters have been reported as up and running.
It appears that some overly concerned fellow Amateurs on the radioreference forums brought the this emission rule technicality to the forefront.
In early 2011 the issue was raised as to the legality of DMR/MOTOTRBO for use under FCC Part 97 . Motorola had classified MOTOTRBO as emission types 7K60FXD (data only mode) and 7K60FXE (data and voice mode) . A careful reading of Part 97.305 led many to conclude that these emission types are not allowed in the Amateur Radio Service
The ARRL petitioned the FCC to revise the rules to clarify the situation and allow DMR on the ham bands . In March 2011, the FCC opened RM-11625 and asked for public comments. While over a year later the FCC has not taken action . Motorola filed with the FCC to add new emissions designators to the MOTOTRBO equipment. The modes of interest to amateur radio are 7K60F7W for the repeater stations and 7K60FIW for the user radios. These emission types are specifically allowed in Part 97 .
Since there have been no public enforcement actions on the part of the FCC, we have to conclude that they don' t see a problem.
June 9th, 2014 the FCC officially approved the use of TDMA, the modulation type used by Digital Mobile Radio (DMR), for ham radio use.
Open source advocate, Bruce Perens, K6BP who has been promoting the Codec 2 project, filed comments in December 2012, in reply to the TDMA debacle.
To quote from his filing:
I am more concerned by underutilized spectrum, and red flags that people throw
that deter experimentation in the hobby.
Amateur Television At the September 2012 DCC in Atlanta, GA, David
Bern, W2LNX presented a paper titled "Experimenting
with High Speed Wireless Networking in the 420 MHz Band."
His paper reports on testing two different manufactures of
802.11 mini-PCI cards capable of operation in the 70 cm ATV sub-band using 5 MHz
bandwith. Test applications were a Webcam video
We urge FCC instead to apply a framework that recognizes the reality of
communication today: one based solely on emitted bandwidth, rather than
increasingly-blurry, and unnecessarily restrictive, definitions of emission
That said I have a few extra picture frames and would be fine framing my first "pink slip" over silly outdated rules in the name of experimentation. As long as your “intent” is pure in amateur spirit, in my eyes this is the only major regulatory requirement you should concern yourself with initially.
I firmly believe that the rules will change as we do. The Part 97 Amateur Radio Service rules should not be inflexible with respect to the encouragement of new digital technologies which improve spectrum efficiency.
70 cm ATV History
In March 1949 Bob Melvin, W6VSV conducted possibly the first Amateur Television transmission in the San Fransiciso Bay area on 423 MHz.
In January 1974, the first 70 cm Amateur Television repeater, WR4AAG was allowed in the Washington DC area, by way of a FCC- STA to wave section 97.61(c). In March 1976, the FCC issued a public notice to waive section 97.61(c) for the period of one year to permit fast-scan ATV stations outside of the repeater sub-bands.
It appears that fast-scan ATV has been formally permitted on 70 cm since February 1959. (1)
The repaid development and expansion of color TV receivers freed up lots of older black and white sets in the back rooms of TV service shops across the country and helped fuel the first boom in Amateur Television (ATV) activity on the part of Amateur Radio operators. Though the 1960s, most operation was done using monochrome equipment. Operation was confined to UHF frequencies and above (beginning what what is now the 420-450 MHz, 70 cm band), which meant that virtually all activity was local in nature and severely impacted by adverse terrain. (2)
While the short-term outlook for conventional ATV is bright, the long-term situation is quite different. Put bluntly, ATV operations based on NTSC (or PAL) broadcast standards have no real viability much past the end of the current decade! This may seem like a harsh assessment, but it is really a call to look seriously at what trends are viable in terms of future development and growth. Let’s start with the basis for the assessment itself and then look at where we should be going. The assessment is based on two issues:
- Equipment availability
- Spectrum management
Given the technological changes in broadcast television, there are only three possible trajectories for future development and they are far from being equal;
1. Do nothing and stay with the NTSC standard.
2. Adopt a broadcast DTV standard.
3. Develop Amateur Digital Standards.
Amateur radio is a communications, not an entertainment service. Given the changes sweeping the TV broadcast industry, this may well be an opportune time to break from broadcast standards with respect to ATV and craft a television option better suited to the needs and objectives of the Amateur Radio service. Properly conceived, such an effort can eliminate dependence on expensive DTV equipment, address the issue of responsible spectrum usage, and bring ATV closer to the amateur mainstream in terms of equipment requirements. If we suspend parochial perspectives and make the assumption that a full-motion television standard has a place in Amateur Radio, it is clear that the third option listed above has a great deal of potential. (4)
The subject of Digital Amateur Television made Stan, WA1LOU’s ARRL Surfin’ column a couple times in 2008. As well as CQ-VHF magazine in 2004.
Despite this, there is still a surprisingly small amount of current D-ATV activities in the United States. (5) Most DATV is in Europe, despite high costs.
It has been said that Image communications were never intended to be a mode independent of phone.
With that said, I tend to agree with option three above.
I am more concerned by underutilized spectrum, and red flags that people throw
that deter experimentation in the hobby.
At the September 2012 DCC in Atlanta, GA, David Bern, W2LNX presented a paper titled "Experimenting with High Speed Wireless Networking in the 420 MHz Band."
His paper reports on testing two different manufactures of 802.11 mini-PCI cards capable of operation in the 70 cm ATV sub-band using 5 MHz bandwith.
Test applications were a Webcam videostreaming program and a file download server program that ran on inexpensive netbook computers.
The test documented in his paper prove a sustainable data rate of 1 Mbit/s over 10 miles.
97.307(f)(6) States; “A RTTY, data or multiplexed emission using a specified digital code listed in 97.309(a) of this Part may be transmitted. The symbol rate must not exceed 56 kilobauds. A RTTY, data multiplexed emission using an unspecified digital code under the limitations listed in 97.309(b) of this Part may also be transmitted. The authorized bandwidth is 100 Khz.”
Section 97.307(f) of the FCC Rules limits the digital data emissions of amateur stations operating to maximum symbol rates. In a digital system the symbol rate is the number of times per second that a change of state occurs. It should not be confused with data rate (also called bit rate) although in a binary system the values will be the same. The symbol rate limits date back to the Third Report and Order in FCC Docket 20777 and became effective on March 17, 1980, when amateurs in the United States were authorized to use ASCII.
Please note that with modulation like OFDM, these limits pertain to individual carriers not the cumulative sum. See: http://www.arrl.org/arrlletter?issue=2007-04-27
"In fact, 3 kHz bandwidth would have been a new limitation, because the present baud rate limit applies to individual carriers," he said. "Therefore, for emissions such as OFDM [orthogonal frequency-division multiplexing], which use multiple carriers, there is no effective bandwidth limit in the HF bands now." Sumner notes that under current rules, a single OFDM signal could conceivably -- and legally -- occupy an entire HF band."
It appears that the 56 kilobaud speed / 100 Khz bandwidth data rule for 70cm came into existence in the early 1980's when the FCC revised the rules to allow experimental digital codes and adopted ASCII as a standard. (6)
DVB-S used by some amateurs for Digital ATV has a signaling data rate that well exceeds this antiquated rule. But that is classified as an image emission, which is exempted from the data emission rules. Spread spectrum emissions are also exempted from the data emission rule. While 802.11b uses direct sequence spread spectrum (exempt from the data rule), 802.11g uses OFDM, which is not classified as spread spectrum.
ATV activity on the 70 cm band hasn't exactly been growing. The following is graph of 70 cm ATV Repeaters (inputs, outputs or both on 70cm). Data was taken from ARRL Repeater Directories for the years show. It's hard to justify, of 20 MHz of space for exclusively for this mode. I feel the gates should be opened to allow other possible co-existable wider band uses.
To help fellow amateurs work towards something of this nature, I tend to
think the 56 kb / 100 khz rule should be done away with for 70 cm. Just
one band higher, these data bandwidth/data rates are non-existent. In
its current form it also prohibits most modern forms of Digital Amateur
Televsion on 70cm.
I'd really like to see some sort of thought at a national level put into revamping some of the band plans. Honestly I thought there would have been some formal discussion on this already.
I'd like to see some encouragement at a national level (TAPR or the ARRL) to document a bi-directional amplifier in one of the various amateur magazines. Since there are more non-overlapping channels on the 5 GHz and 900 MHz band I would encourage it to be for either of those bands, or 3 GHz.
It's also feasible to imagine that future D-Star radios could incorporate the high-speed digital data mode (128 kbps - that is presently only available on 1.2 GHz due to the present regulations) on the 70cm band.
In 2011 a company based in Singapore, called Doodle Labs offers the industries first OFDM broadband Atheros based radio transceivers for the Amateur Radio Bands capable of 5 MHz channel widths in the 420-450 MHz, 70 cm band. In 2012 a second company based out of Canada, called Xagyl Communications also makes available a Atheros based radio capable of operation on the 70cm band.
At Dayton 2012, a new company North-West Digital Radio presented a prototype of just that. The Universal Digital Radio (aka UDR56K) is a high speed 70cm data radio.
Sadly, thus far I have seen little efforts in this area. I feel that relaxing the rules a bit will help encourage experimentation and development to foster new uses for the lower portion of the 70cm band, thusly helping protect the spectrum.
While I feel there are enough loopholes, I'm well aware that some FCC rules petitions have been in the process for years. I think if several of us were to apply for STA's, this might help expedite this, or at least help build the case for rule modification.
Excerpt from 73 Magazine, August 1985.. QRX Column edited by Perry Donham KW1O:
"DON'T BE A PROBLEM," said FCC Commissioner Ray Kowalski to a conference of repeater coordinators at the Dayton Hamvention. Kowalski, addressing a forum on VHF spectrum management, made it clear that he is concerned about the future of amateur radio. "The current political mode for dealing with problems is to get rid of them," he explained. "You are sitting on very valuable spectrum. There are sharks out there who have mentioned that spectrum and would love [to have] it. Think on how it plays in the halls of the FCC if someone says, 'This has become a problem service; let's get rid of it. It will go away and we can give that spectrum to people who need it [instead] of a bunch of hobbyists.' That's how it will play if it comes down to a solution to solve a problem. Do not become a problem." More specifically, the Commissioner chided hams for running so quickly to the FCC with every little problem. Kowalski reminded the group that amateur radio is a self-policing service and that we should be able to solve our problems with a minimum of regulatory action. "Don't come running to us for some kind of policy or rulemaking. . .you won't like the solution!"
If you agree with the logic that I have stated here, I encourage you to be proactive and drop a line to your section manager or other division director on the subject. Or if you plan to participate with active experimentation, reportedly Dan Henderson, N1ND at ARRL headquarters can provide anyone with the necessary information to develop and file STA application with the FCC. Bear in mind that special temporary authorization bears a $60 filing fee, and are only good for 6 months.
[Update Oct 2013]
In October 2013, the ARRL proposed to modernize the rules for data transmissions. The baud rate limits will be removed, and will governed by just the maximum bandwidth portion of the existing rules.
End the end of December the League’s petition toped the FCC’s “Most Active Proceedings” list. As of the December 23 comment deadline, more than 850 comments had been filed, which is a large number indicating that the issue of data communications is an important one in the Amateur Radio Service. The majority of the filed comments are supportive of the proposals in the Petition.
(1) What Bands Available? (Happenings) - Page 67 March 1959 QST
(2) 1.8 Image Communications Handbook
(3) 10.5 Image Communications Handbook
(4) 10.6 Image Communications Handbook
(5) http://www.arrl.org/news/surfin-more-going-atv-digitally and http://www.atco.tv/DVBSDetails.aspx http://groups.yahoo.com/group/DigitalATV/
(6) Experimental Digital Codes Now Permitted Above 50 MHz (Happenings) - November QST 1982- Page 56 and FCC Releases Official Wording of New ASCII Rules (Happenings) - QST April 1980, Page 74