Help sought - amateur satellite service vs D-star
Hello,
I apologise for the intrusion of my first message on this list - consider me an incidental lurker, incidental AMSAT-UK colloquium visitor, and incidental easysat user. I just don't have the cycles to do more, sorry.
I ask your assistance in the following matter.
Background In the Netherlands, 436-440 MHz is secondary to the amateur and amateur sat service. The folk experimenting with D-star on 70cms use a fairly large shift of 9.4 Mhz, resulting in a typical setup of 430.400-430.600 in and 439.800-440.000 out. Unattended stations (like D-star repeaters) do require a special license here.
Recently, issuing of unattended licenses has come to an extreme halt because the Dutch regulator has started to allocate frequencies around 439.500 and upwards for Differential GPS (DGPS).
The Dutch amateur community contests the use of this frequency for DGPS, claiming it is in violation with ITU allocations. Amateur clubs in neighbour countries, *as well as telcom regulators in those countries*, agree on this matter and believe AT-EZ is mistaken. But AT-EZ are also stubbern, and supposedly fear damage claims from systems already deployed.
The net result is that currently, no D-star repeater license is issued because the output frequency proposed cannot be licensed for unattended use, according to the regulator.
Recently.. The D-star community, having fear of not being able to use their equipment, is now proposing to use a shift of 7.4 MHz shift: input ~430.400-430.600, output 437.800-438.000. The output obviously collides with the amateur radio satellite service, but the proposal does not mention this at all, nor does it mention any remedy for this interference, which the amateur radio service would inflict on itself, on a worldwide (at least European) scale.
I don't need to explain what a 'local hole in allocation' does for the worldwide sat service, no?
Not to mention, if the Amateur Radio Service doesn't take it's own protection seriously, why would regulators need to take these interference concerns seriously?
I believe this plan is very poorly thought-out and should be rejected and complained upon on an International scale.
I believe that the amsat community should respond on this matter. I also believe that our IARU-contacts should be used to fix this proposal.
Data So far, the only information I found on this, is in Dutch, so you may need to babelfish things: http://www.d-star.nl/ http://zendamateur.com/viewtopic.php?f=16&t=3913&p=29449
There are 2 amateur radio clubs in the Netherlands. One is VERON (IARU representative), the other one is VRZA. While VRZA is not an IARU representative, both VERON and VRZA have bi-annual meetings with the Dutch regulator (which, I must admit, have been in better spirit in the past than they are now, because of the DGPS issue, but I digress)
The plan, as described on the URL above, claims that the VRZA "thinks this proposal is a good idea".
I kindly ask AMSAT folk, and especially those with IARU contacts, to express their concerns about this proposal.
The person championing the proposal is PA0HWB, [email protected] (I realize the irony of Hans using the AMSAT alias to damage the amateur sat service..)
For VRZA, I believe the best contact is the chair PG9W, pg9w (at vrza.nl). For VERON, I think PB0AOK (at veron.nl) is probably a good place to send mail to. You probably have better contacts than I have - please use them.
I apologise for this lengthy message but hope this crazy proposal can be dealt with appropiately.
Thanks in advance, 73
Geert Jan PE1HZG
At 07:24 AM 9/9/2009, Geert Jan de Groot wrote:
Background In the Netherlands, 436-440 MHz is secondary to the amateur and amateur sat service. The folk experimenting with D-star on 70cms use a fairly large shift of 9.4 Mhz, resulting in a typical setup of 430.400-430.600 in and 439.800-440.000 out. Unattended stations (like D-star repeaters) do require a special license here.
OK, so what do FM repeater owners do? Asking that, to see if there's any other places the D-STAR systems can be put. Over here, D-STAR repeater allocations are in the same parts of the bands as FM ones.
Recently.. The D-star community, having fear of not being able to use their equipment, is now proposing to use a shift of 7.4 MHz shift: input ~430.400-430.600, output 437.800-438.000. The output obviously collides with the amateur radio satellite service, but the proposal does not mention this at all, nor does it mention any remedy for this interference, which the amateur radio service would inflict on itself, on a worldwide (at least European) scale.
This could create significant QRM across Europe, as any satellite with an input on those frequencies and within range of an operating D-STAR system would suffer QRM. Satellites with downlinks in this range would be unusable within the coverage area of a D-STAR system on the same frequency, though in a lot of cases, Doppler shift would allow at least some of the pass to be worked.
I believe this plan is very poorly thought-out and should be rejected and complained upon on an International scale.
I'm not sure what can be done about the DGPS issue, given the relative status of amateur radio and commercial interests in most countries, but the issue of allocating repeater outputs in a satellite subband is something that goes beyond national borders, especially in Europe, where many countries are very small.
73 de VK3JED / VK3IRL http://vkradio.com
[Apologies as it's slightly off-topic, I do my best]
On Wed, 09 Sep 2009 16:39:20 +1000 Tony Langdon wrote:
The folk experimenting with D-star on 70cms use a fairly large shift of 9.4 Mhz, resulting in a typical setup of 430.400-430.600 in and 439.800-440.000 out. Unattended stations (like D-star repeaters) do require a special license here.
OK, so what do FM repeater owners do? Asking that, to see if there's any other places the D-STAR systems can be put. Over here, D-STAR repeater allocations are in the same parts of the bands as FM ones.
Good question, long and complex answer. Briefly, (voice) repeater pairs are allocated geographically. So, there is one slot (but only one slot) per area. If there are multiple groups who want to build a repeater, then the single license would alternate between these two groups every three years.
On 70cm, voice uses 1.6 MHz shift down. The repeater I built (PI2EHV) does 431.700 in, 430.100 out.
D-star is currently considered "digital/packet" for which the 9.4 MHz shift pairs are set up. And the output collides with the newly "allocated" DGPS users. Hence, no new licenses are issued, and the D-star folk are looking for a new place. Which is all nice and well, but the "new place" SHOULD NOT be in the sat band for all the reasons you mention, and I believe they should be told.
I've repeatedly asked why they are so hang up on large shifts (causing them to need to take this extreme measure), but I get no answer. To me, the difference between GMSK and NBFM is small, and if 1.6 MHz shift can be made to work for NBFM, it can be made to work for GMSK. And, obviously, a smaller shift gives much more flexability to (potentially) find a good spot. [that is, if we would decide to accomedate the illegal allocation for DGPS, which I don't think we should, but that's another matter].
Anyway, the current proposal would hurt the amateur sat service, *as well* as negating a careful allocation process the amateur radio community has built for tens of years. While the proper allocation of this mode is beyond the scope of the AMSAT community, the current, improper proposal *is* within scope, and I hope people will raise their voice on this.
Thanks,
Geert Jan PE1HZG
Hi Folks,
I had lots of answers to my previous post - this is just to say a big thank you to all who responded - too many to reply individually!
It does seem a case of you pays your maoney and takes your choice (ie the more you pay the more convenient/faster the journey is!)
Again, many thanks to all who responded! I'm really looking forward to the Symposium!
73 Jim G3WGM
participants (3)
-
Geert Jan de Groot -
Jim Heck -
Tony Langdon