[d-star] Amateur Radio Newsline Report - RADIO LAW: NFCC ASKS FCC TO DECLARE DIGITAL VOICE REPEATERS THE SAME AS ANALOG
Mark Thompson
wb9qzb at yahoo.com
Mon Oct 1 00:32:52 CDT 2007
Amateur Radio Newsline Report 1572 - September 28, 2007
Amateur Radio Newsline report number 1572 with a release date of
Friday, September 28, 2007 to follow in 5-4-3-2-1.
The following is a Q-S-T. The National Frequency Coordinators' Council
asks the FCC to declare all digital voice repeaters follow the same
rules as analog F-M repeaters, Australia makes ready for digital voice
operations and four New England repeaters voluntarily shut down over
interference to Pave Paws radar.
Find out the details on Amateur Radio NewslineT report number 1572
coming your way right now.
**
RADIO LAW: NFCC ASKS FCC TO DECLARE DIGITAL VOICE REPEATERS THE SAME
AS ANALOG
Is a digital voice repeater really a repeater or is it something else
yet to be defined in law? The National Frequency Coordinators' Council
believes that anything that repeats voice in close to real time is a
repeater, and its now asked the FCC to declare this to be the case.
Jay Maynard, K5ZC, is president of the NFCC. He explains the back
story that lead his organization to act:
--
K5ZC: "When D-Star started really taking off, somebody wanted to put
up a D-Star repeater. He went to his local coordination council and
wanted to put up a 2 meter D-Star repeater. He went to his local
coordination council but was told no because we do not have any
frequencies available for you. In desperation -- I don't know if
that's a truly accurate word but its close enough -- they (the want to
be repeater owners) went to the FCC and described what D-Star did in
such a way that the FCC -- specifically Bill Cross -- concluded that a
D-Star repeater really wasn't a repeater and therefore did not have to
operate in the repeater subbands."
--
That night be all well and good if it were only D-Star and other
digital repeaters that fell into this category. Unfortunately, many of
today's analog FM systems alo include a slight audio delay to
facilitate control or linking. And it soon became apparent that this
opinion by Bill Cross could lead to a lot of problems on the VHF and
UHF bands:
--
K5ZC: "This guy said 'fine' and he put his machine up on 145.61MHz
with a minus 1.2 MHz offset and went to town That gave D-Star a
foothold in that area, but it also opened up a real can of worms
because the way that Bill Cross wrote the message, he said that its not
simultaneous because there is a delay in the path between the input
and the output.
The problem there is that lots of (analog) repeaters have delays
between the input and the output. Anyone that's running an RC-850
(controller) or other computerized controller has a delay. And it was
only a matter of time before some bright spark read that message and
said: 'Ah hah! My repeater does not transmit simultaneously either.
Its not a repeater and I can get on outside the repeater subbands and
go to town."
--
And that's what had frequency coordinators concerned. They did not
want to see a return to the repeater turf wars that marked the early
days of FM relay operation:
--
K5ZC: "In the late 1960's and early 1970' there was a lot of
proliferation of repeaters. That was really the 'golden age' of
repeater construction. And in that era is when frequency coordination
first came about because you had people wanting to put their repeaters
up all on the same frequency, and that did not work very well -- as you
might imagine.
Part of the regulation that came down to stem that tide was restricting
repeaters to parts of the ham bands so that they wouldn't take over the
entire band. After all, there are folks that do other things than
operate FM repeaters on 2 meters and on some of the other bands and
they have just as much right to operate on the ham bands as repeater
operators do. And that's where the restriction (of repeaters) to
certain subbanbds comes from."
--
After debating the matter for several months as more and more digital
voice systems took to the air, the majority of NFCC members agreed that
it was imperative for them to let the FCC know that they believe any
device that retransmits an audio signal in near to real time is a
repeater and should be treated as such.--
--
K5ZC: "What the NFCC did was vote to ask the FCC to treat anything
that asks like a repeater, as a repeater. This was a formal motion and
vote of the council."
--
Specifically, the letter states that the NFCC believes that any amateur
station, other than a message forwarding system, that automatically
retransmits a signal sent by another amateur station on a different
frequency while it is being received, regardless of any delays in
processing that signal or its format or content, is a repeater station
within the meaning of paragraph 97.3(a)(39) of the FCC rules and should
be treated as such. In practical terms, it means that D-Star, APCO 25
and any other repeatable digital voice system that comes along would be
restricted to operation in the FCC recognized repeater subbands. That
they could not simply set up shop on any frequencies that the system
owner might choose to the detriment of weak signal, satellite or any
other user of any ham radio band. It's an action likely to be lauded
by groups like those just mentioned but likely will be condemned by
those wanting to put up digital voice repeaters. If the FCC finds
itself agreeing with the N-F-C-C, then it will mean digital voice relay
enthusiasts will have to get in line behind all of the others waiting
for repeater pairs for their old line F-M systems.
Obviously we have only scratched the surface of this controversial
topic. If you want to learn more, take your web browser over to
www.therainreport.com. That's where you will find Part 1 of a two-pard
in-depth interview with NFCC President Jay Maynard, K5ZC. Again that's
www.therainreport.com or on the phone at area code 773-358-7845
(ARNewslineT)
**
EMERGING TECHNOLOGY: AUSTRALIA MAKES READY FOR D-STAR
The United States is not the only place where digital voice repeaters
are coming of age. Australia's National Technical Advisory Committee
or NATC has been considering how best to accommodate narrow band
digital voice technologies such as D-Star. They have now made a number
of proposals. Peter Young, VK3MV, of the WIA News reports:
--
Firstly, in the 2 meter band, digital repeaters will be assigned to
frequencies in the 146 to 147 MHz band, using the space between
existing FM repeater channels. This is known as inter-leaving and is a
common method of assignment to increase spectrum efficiency. The are
some compelling reasons to take this approach for 2 meters, one is to
remove the potentially annoying "drone" of digital signals, and
secondly, the lack of normal FM repeater channels in some parts of
Australia. It also seems to make sense to have the uniform arrangements
across all of Australia.
The arrangements for simplex operations, again to separate digital and
FM emissions, NTAC has recommended the best area for simplex D-Star
activity would be the 145 MHz segment. One suitable channel that is
clear of other use is 145.125 MHz and should be used as the national
simplex digital channel.
On 70cms, where there is less congestion, NTAC has recommended that the
first fifteen repeater channels, that is, 438.025 to 438.375 MHz, be
used for D-Star type activity.
NTAC has recommended that the arrangements for simplex activity on 70cm
be centred on a national channel of 438.900 MHz, with secondary
channels 12.5 KHz either side of the national channel.
For the 23cm band, NTAC has recommend that repeater channels be
assigned in the high end of the 1293 to 1294 MHz repeater segment. And
on the 23cm, there is already a digital simplex segment between 1298
and 1300 MHz. As D-Star on this band uses a 128 KHz emission bandwidth,
it is suggested that channels are spaced at 200 KHz intervals,
beginning at 1298.1 MHz.
I'm Peter Young VK3MV
--
Australia's National Technical Advisory Committee will review these
arrangements as D-Star digital activity develops. Further information
can be found on the W-I-A website and will be included in the next
edition of the WIA call book. (WIA News)
**
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