D-Star Coordination's in the eyes of the FCC

[KS4VT]

Please see the below e-mail from the FCC and their opinion of coordinating D-Star in the amateur radio spectrum. I have the original e-mail available and it can be forwarded if someone want's to see it.

73
Mark KS4VT
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Mark,

As best as I can tell (and I am not going to take the time to do a word-by-word comparison with the original e-mail) what you have received is a correct copy. #You also, however, need to get a correct copy of the inquiry, in fact the entire e-mail exchange would be very useful, before you form any conclusions or make any decisions based on one piece of an e-mail exchange.

William T. Cross
Mobility Division
Wireless Telecommunications Bureau
Federal Communications Commission

-----Original Message-----
From: Mark Filla [mailto:MFilla@co.palm-beach.fl.us]
Sent: Wednesday, November 15, 2006 7:46 AM
To: William Cross
Cc: ks4vt@adelphia.net
Subject: Amateur Radio D-Star


Mr. Cross,

The following text shown below was forwarded to me by an amateur radio operator that is working with the Florida Repeater Council where I am one of the 8 Directors for the State Of Florida. #Can you please verify for me if your statements below are accurate due to it
being forwarded in the body of an e-mail and not as an attachment.


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From an email I received on August 1st (8:02am):

Mr. Burningham:

Thank you for the explanation. #The word "simultaneously" does not have a special definition within Part 97. #Therefore, it is used with the meaning that you found in the dictionary. #Because the system as you describe it "does not simultaneously re-transmit the transmissions of another amateur station" but rather, "there is a noticeable time lag on the down link data stream which is caused by the decoding, processing, and encoding by the D-STAR system," and the system is a "store-and-forward type system just like existing amateur packet radio," it apparently is not a repeater within the meaning of Part 97 and a repeater coordinator should not coordinate the system. #In fact, a repeater coordinator does not have authority under Part 97 to coordinator non-repeater systems. #Therefore, it should deny or return your application for coordina! tion. #

You are correct that "The existing rules make a distinction between repeaters and digital stations..." #Part of that distinction is that repeaters may be coordinated and are limited in the frequency segments that they may use to transmit and receive messages from other stations. #Stations transmitting digital emissions, however, are not "coordinated" other than by cooperation between licensees, including cooperation with licensees of repeater stations. #As such, the licensee of stations transmitting digital emissions are responsible for the proper operation of the station, including #cooperating with other licensees in selecting transmitting channels and in making the most effective use of the amateur service frequencies, and insuring that the station does cause harmful interference to the transmissions of other stations, including stations transmitting messages through repeaters. # See Sections 97.103, 97.105(a), and 97.101! (a), (b), and (d). #

William T. Cross
Public Safety an d Critical Infrastructure Division
Wireless Telecommunications Bureau
Federal Communications Commission


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Thank you for your time and await your reply.
Mark Filla KS4VT

Very interesting...looks like it is time fir a rules change in the definition of "repeater" in order to keep up with the times.

[KS4VT]

In this day of digital signal processing for almost every type of high end wireless device what you say does have some merit as most systems have a noticeable delay and could be considered store & forward. The only problem I see is that the term would have to be modified in every other section of the FCC's R&R's to be consistent as we aren't the only service using repeaters.

[KD6NIG]

It will be interesting to see what happens. If the 'repeater' uses a input and an output frequency, I would think by definition that would be a repeater, but who knows.

Personally I think the internet access feature of it will be abused, and the FCC will pay more attention to that in the long run anyway. But if its got an input and output frequency, I think it being digital wouldn't matter-but then you read the above and start to wonder a bit.

I would think though that coordination will have to cover it-otherwise people could just start throwing up D-star repeaters everywhere, and then interference complaints will rise. Being uncoordinated but using the same coordinated repeater space isn't going to work for long-especially in areas like where I'm at in California, where there is a waiting list for 2m frequencies to this day, and any interference from someone just tossing up a repeater anywhere is noticed mighty quickly.

[WA2ZDY]

Mark, I understand the gist of this but being one of the great unwashed I don't know details about D-Star. How long a delay is there while the signal is processed through a repeating (non-)repeater?

[n5rfx]

All repeaters have delay, even the analog types (you know that speed of light thing). Audio traveling through the receiver, controller, and transmitter circuits doesn’t get from point A to point B instantly. Audio that is digitally processed just has a longer delay.

If something is truly store and forward, it should be able to work on a simplex channel, and not be limited to half or full duplex. I have a commercial telemetry repeater that is a store and forward device. I can operate it with identical input and output frequencies, or I can operate it with different input and output. Also the data can be stored until it is safe to transmit. I don't think D-Star fits that store and forward category, but I may not be looking at this correctly.

73,

Mark N5RFX

[KS4VT]

Quote[/b] (WA2ZDY @ Nov. 16 2006,14:33)]Mark, I understand the gist of this but being one of the great unwashed I don't know details about D-Star. #How long a delay is there while the signal is processed through a repeating (non-)repeater?
Beats me Chris, I have never used D-Star and have only messed with it at a hamfest between 2 radios. I'm a regular user of Project 25 (P25) digital in the ham bands that is the US LMR digital standard.

[ab0wr]

Quote[/b] (n5rfx @ Nov. 16 2006,11:53)]All repeaters have delay, even the analog types (you know that speed of light thing). #Audio traveling through the receiver, controller, and transmitter circuits doesn’t get from point A to point B instantly. #Audio that is digitally processed just has a longer delay.

If something is truly store and forward, it should be able to work on a simplex channel, and not be limited to half or full duplex. #I have a commercial telemetry repeater that is a store and forward device. #I can operate it with identical input and output frequencies, or I can operate it with different input and output. #Also the data can be stored until it is safe to transmit. #I don't think D-Star fits that store and forward category, but I may not be looking at this correctly.

73,

Mark N5RFX
You bring up a good point.

If a D-star repeater is NOT a repeater, how long will it be until complaints are lodged that a user is taking up more space than is required for transmissions? (i.e. separate input and output frequencies).

That didn't use to be frowned upon (e.g. 25-30 years ago). Today it is considered as harmful interference if you take up 7-10khz for separate receive and transmit channels when you are NOT a repeater.

This definition may initially sound good for D-star but may turn out to be an albatross in the long run.

tim ab0wr

[K0RGR]

I would think this interpretation would apply to any digital voice system, including the APCO systems.

This muddies the whole question of what digital voice is. Is it voice or is it data?

Once again, the federal agency charged with promoting the advancement of the radio art seems to be trying to hold it back. But, on the other hand, if DSTAR is not a repeater, it frees it from the restrictions on repeaters. If it's a digipeater, then the digi rules would apply, so it's still OK to do automatic control.

If DSTAR is not a repeater, it is not restricted to the repeater sub-bands, either. CQ 145.6 Mhz...

[WA2ZDY]

Thanks Mark, I know about P25 and your use of it. I thought you might have learned about DStar too.

I'm with Tim, it sure as heck sounds to me like a repeater. To be store and forward I would think the data must be completely uploaded before it is repeated. Kinda like those old Radio Shack "simplex repeaters." Even packet digipeaters fell into that. And like RFX said, they use only one frequency.

I think FCC goofed on this definition.

[n5rfx]

97.3(a) 39 defines repeater as an amateur station that simultaneously retransmits the transmission of another amateur station on a different channel or channels.

If it is the word simultaneous that is being interpreted as exactly at the same time without any circuit propagation delay, then there has never been, nor never will be any piece of equipment that is a repeater by this definition. Be reasonable, or prove that your D-Star repeater input and output can exist on the same frequency. Attempts to circumvent coordination are disingenuous.

73,

Mark N5RFX

[WE6JBO]

D-Star is in stock. You can get yours by clicking on the D-Star red, white and blue advertisment on the top right hand corner of this website.

[KS4VT]

You just don't get it now do you....why don't you re-read the whole thread for a change and comment with something substantial.

[ke4pjw]

Quote[/b] (KS4VT @ Nov. 21 2006,11:04)]You just don't get it now do you....why don't you re-read the whole thread for a change and comment with something substantial.
Can you post "the explanation" Mr. Burningham sent to Mr. Cross?

We are missing what Mr. Cross is responding to.

[KS4VT]

I have asked for that information but have yet to receive it. As soon as it arrives I'll post it.