General Information

The PAPA System

PAPA D-Star

D-Star News Archive

6/17/2007

PAPA D-Star Project Status

The importance of opening up the Gateway to fully utilizing the internetwork capability of D-Star is that the ICOM supplied Gateway software will only run on an OS that ICOM supports. By having a developed open source version of Gateway-like software, we will have the freedom of running a Gateway on an OS of our choice, which may differ from the OS that ICOM supports but which we might prefer for other reasons. If successful, the effort by talented and highly motivated amateurs to accomplish this will therefore provide us with important flexibility in the deployment and linking of our repeaters with each other and with other non-PAPA repeaters nationwide. The good news from Dayton is that this effort appears to be well underway, as noted above, through opendstar.org.

6/10/2007

I’ve obtained permission from John Hays, K7VE, to publish his post in illinoisdigitalham (a Yahoo group) in full, in case you are not in, or have no interest in joining, the Yahoo group. It makes interesting reading. John’s post is appended to the bottom of this page.

6/1/2007

Several of our fellow members went to Dayton this year, including Cecil Casillas. Cecil attended the D-Star event Friday night and made a number of valuable contacts. What follows is his report, as best as I can convey it, along with some additional information that has been gathered since the event as well as general status of the project.

Dayton Highlights

The D-Star forum was very well attended, with approximately 250 people for a 3-hour event. Cecil met and talked with a number of hams who are involved in this technology. My overall impression is that he was very impressed with the intensity and excitement of the group and rated ICOM’s presence at the convention generally very highly, though clearly it is the user community, through forums, newsgroups, eGroups and personal contact, that is providing support for D-Star rather than ICOM.

Cecil reported that there is a significant level of experimentation going on in the ham community with D-Star technology. Among the highlights, he reports that the codec, which is the only proprietary part of a D-Star system other than the Gateway software, is accessible, opening the door to amateurs to build D-Star compatible radios and to commercial manufacturers to offer D-Star compatible products, including radios and perhaps repeaters and repeater controllers. To underscore the point, Cecil (and presumably everyone else present) saw a demonstration of a home-brew 2-meter D-Star compatible radio designed and constructed by an amateur. An interesting perspective on this is in the post by K7VE:

http://groups.yahoo.com/group/illinoisdigitalham/message/2018

While the ICOM D-Star repeater controller does the job, the consensus seems to be that being so new it lacks many of the functions and features of commercially available analog controllers. Cecil, therefore made it a point to visit for a good while with Linkcomm. While Linkcomm does not yet offer a D-Star capable controller, the developments described above make this a very real possibility in the near future.

As far as numbers go, Cecil learned that there currently are 53 repeaters on the Gateway, up from fewer than 30 at this time last year. Based on earlier back-of-the-envelope calculations this suggests to me that there are very probably 80 to 100 D-Star repeaters on the air, since not every repeater on the air uses the Gateway. In the Los Angeles there are known to be at least six repeaters, including our two operational repeaters, Oat and Palomar, and there is also significant activity in the Bay Area and in San Diego.

One of the challenges we have faced in implementing D-Star is that the repeater is somewhat of a black box. However, Cecil, working with Art McBride, KC6UQH, have manufactured a device that allows receive sensitivity to be measured using two radios and a conventional service monitor, which Cecil took to Dayton to show. Cecil in turn discovered that J.B. Archinard, KT4AT, has developed diagnostic software that allows for visual display of the states of a number of systems within the repeater without opening the cover. We have since obtained the software, courtesy of KT4AT.

We also learned that there is a significant move afoot to develop Gateway-like software under the open source model, perhaps under GPL. The site for this project will be opendstar.org and is now under construction. Keep checking to see how this is coming along. Other than the codec, the Gateway is the only significant proprietary component of ICOM’s D-Star system that will need to be worked around to make home-built systems fully D-Star network compatible (as opposed to simply being D-Star repeater compatible, which has already been achieved). This is just the sort of problem that may lend itself to the open source model. The significance of the Gateway is that it allows us to link our repeaters with each other and with other organization’s D-Star systems. At Dayton we learned (what we already suspected) that contrary to their published literature, ICOM has no plans to implement the 10 GHz microwave link radio, as a means of linking D-Star repeaters, in the US.

PAPA D-Star Project Status

With respect to software, ICOM’s documentation specifies that the ICOM supplied Gateway runs only on Fedora Core 4 or Redhat. However, Cecil learned that successful operation has been achieved on Ubuntu and separately we have heard reports locally that the Gateway software will run on Fedora Core 6. We’ve since learned from Robin Cutshaw, AA4CC, that Core 5 and Core 6 should work, if configured properly. Tentatively we plan to install Centos 5 (Redhat Enterprise) on Oat, which should be even more stable than Fedora Core 6.

The Picnic

We plan to set up a table featuring D-Star radios at the upcoming picnic so that PAPA members can try out the radios and get a feel for the experience. For power, we plan to use the generator that is the Grand Prize and I will have a tripod mounted ATAS 25 antenna, which is what I use here at home for OAT. It is unlikely we will have the Gateway up by the time of the picnic, but coverage should be good and it will give anyone interested some hands-on experience with the hardware. We will also have a laptop with the software necessary to program several of the radios currently owned by members in case anyone would like help with theirs.

Post on illlionoisdigitalham (a Yahoo group) by John Hays, K7VE

Nate,

I know where you are coming from, I'm a big Open Source (in its broad

definition - see Wikipedia article) advocate. I have been using Linux,

GNU, MySQL, Apache, ... practically from their beginnings. But have

another perspective on some of your points.

Open Source is not free. There are implementation, support, and

maintenance costs among other things. What it does allow though is open

review and community participation in the development of products, which

I believe makes them better products. The user/implementor of Open

Source can choose from a market of ideas and make trade-offs between

paying for the costs or absorbing them through their own labors.

We use all kinds of proprietary products in Amateur Radio, from vacuum

tubes to microprocessors. Whether we homebrew or use commercially

built products, we use building blocks of proprietary technology.

D-STAR was developed as an open protocol, not open source. I resisted

it until recently because I don't have the design skills to design and

build the hardware platform inside a D-STAR radio (nor the math skills

to create a great Vocoder from scratch). Icom was the only game in town

and while they make great products, they haven't caught the vision of

opening and documenting their interfaces so that others can build on

their building blocks. (Which would lead to more sales.) Then I learned

that there were a few folks out there working on open designs for

hardware, so I took the plunge and bought a D-STAR handheld (an IC91AD)

and headed off to Dayton with it in hand (could have saved some money by

waiting until I was there BTW) and one of the first things I saw was a

working 2 meter D-STAR radio, homebrewed completely from components and

user written software (WHOO-HOO, thanks "Mel"), a few months ahead of

when I expected to see it. I also saw a board that can emulate the

inter-repeater/controller control line protocols Icom has implemented as

well as the Internet protocols that gateways use to talk to each other

and the builder has written software that can be used to create open

source replacements for the controller and gateway. So now, there is

hardware and software to build our own repeaters and gateways (that

don't necessarily have to do it the Icom way of implementing the open on

air protocol) and create our own applications that run in the network.

One could probably do the same thing with P25 (open specification) on

the radio side, replacing the vendor proprietary stuff on the back side

and, in software, create a gateway to route between them (at least in

the local zone) -- It remains to be seen if that could be done with

Mototurbo technology (is their on air protocol patented?).

However, in each of the D-STAR (OpenDSTAR - see the coming opendstar.org

site) and P25 examples they will still be built using some proprietary

components such as the AMBE2020 and IMBE vocoders, A/D and D/A chips,

microcontrollers, etc. as building blocks. That is how Amateur Radio

has always been done. Our great opportunity is to build really "killer"

applications for the technology that brings Amateur Radio back into

relevance to the regulators. I don't care if someone buys the

technology or builds it, but open source is important to innovation in

our hobby -- right now D-STAR is ahead in that game thanks to some

pioneers who are providing the tools and building blocks in an open and

"free" approach.

== John K7VE