Chris noted that HQ staff are receiving
complaints based on confusion over the classification of digital voice. No
doubt some are concerned that DV will show up in the data / CW bands.
Others are concerned that their use of digital voice on HF will be restricted. With
respect to D-Star, which is the subject of the calls I'm getting, I suspect
that the absence (as far as I can tell) of definitive guidance is due to the
dual nature of that mode; it is not just digital voice but both voice and data
sent simultaneously. I do not find sufficient specifics in either Part
97.3 or in Part 2.201 to be able to respond to my concerned constituents with as
definitive an answer as they are requesting. Although, being neither an
attorney nor an engineer, I may well be missing something, here's what I find:
Part 97.3(c)(5) defines "phone"
as "Speech and other sound emissions having designators with A, C, D, F,
G, H, J or R as the first symbol; 1, 2 or 3 as the second symbol; E as the
third symbol. Also speech emissions having B as the first symbol; 7, 8 or 9 as
the second symbol; E as the third symbol". From what I can tell, D-Star
voice has a designator of 6K00F7W, which, because it has "two or more
channels containing quantized or digital information" does not fit within
the foregoing definition of "Phone". D-Star includes both a
voice channel and a data channel; hence the "7" and "W" in
its emission designator.
Part 97.3(c)(2) defines "data"
as "Telemetry, telecommand and computer communications emissions having
(i) designators with A, C, D, F, G, H, J or R as the first symbol, 1 as the
second symbol, and D as the third symbol; (ii) emission J2D; and (iii)
emissions A1C, F1C, F2C, J2C, and J3C having an occupied bandwidth of 500 Hz or
less when transmitted on an amateur service frequency below 30 MHz."
Clearly, D-Star, with its voice component, does not fit there, either.
Since Icom has been selling HF+
transceivers with built-in or optional D-Star capability (IC-7100 and IC-9100,
respectively), there have been D-Star HF nets on nearly all our HF bands.
It is unclear to me - and, apparently to others - as to where in the FCC rules this
phone + data mash-up is authorized on HF. (Why anyone would want to use a
non-weak-signal mode on HF is beyond me, but that's another question.) The
IC-9100 operating manual section on DV has illustrations showing only VHF and
UHF frequencies on the displays, and there is no mention of using DV on HF.
Still, people are putting their D-Star radios on the lower bands. As long
as they are unsure as to where their authorization to do so comes from, we'll
probably keep getting questions on the topic.
Sorry for the bandwidth, but I would
really like to have a chapter-and-verse response for my members. A
secondary question is where a D-Star user would find recommended procedures for
avoiding causing interference to weak-signal modes (such as, listen on SSB
before transmitting on digital), assuming that a listener in the D-Star mode would,
like one on FM, not hear CW, SSB or other amplitude-based signals..
73,
Marty N6VI
From:
arrl-odv-bounces@reflector.arrl.org
[mailto:arrl-odv-bounces@reflector.arrl.org] On
Behalf Of Chris Imlay
Sent: Tuesday, November 26, 2013
1:09 PM
To: dsumner@arrl.org;
arrl-odv@arrl.org
Subject: [arrl-odv:22114] Re:
RM-11708 erratum
However, there is some substantial
feedback being received at Headquarters about the Petition in other respects,
most notably with respect to the 2.8 kilohertz proposed occupied bandwidth
limit for data communications. The principal misunderstanding found in
these complaints is related to the classification of digital voice. According
to the FCC rules, digital voice is classified as voice, not data.