Sunday, November 20, 2011

70cm DATV and the future




Here is an interesting excerpt from an articled titled "Earth-shaking ATV, Plus.." by N5EM in CQ-VHF Magazine, March 1999 that I recently ran into.


Digital ATV Is Heating Up!

Since I last wrote about some possibilities in Digital Ham TV (DHTV), several reports of experimentation have been received. As long as there are efforts to make digital ATV a reality , I'll report on the work and keep you informed. One of the best developments is the previously mentioned e-mail re-mailer for DHTV. Check out the Web address for information about reading and posting messages to this list.

For those of you who may not have yet experienced an e-mail list, it is the method of sharing information in the information age . By "subscribing" to the list, you become a recipient of any e-mail message that is sent to the list. Anytime a message is e-mailed to the list, it is re-mailed to every subscriber, all in a matter of minutes. It lets people share ideas and information on a near real-time basis with like-minded experimenters any where in the world.

There are e-mail re-mailers (also called "reflectors ") for virtually any subject the mind can conceive of. Some have only a handful of subscribers while others have literally hundreds of thousands . There are several good e-mail re-mailers for the ATV community. One place to find out about them is at the Houston Amateur Television Society's Web site located at .

Some work with DHTV this month comes from Les Rayburn , KT4OZ, and Tom Askew, KB5IHI. They've been experimenting with video transmission using IBM Wireless LAN PCMCIA cards operating on 2.4 GHz. In their tests, Les and Tom used two laptop computers and wireless LAN (local area network) cards, transmitting Real Media data streams approximately 800 feet and resulting in actual ATV QSOs. Quoting from their test report,

"At 28.8 kbps encoding, it was...possible to have two-way (full duplex) QSOs, but at 56 kbps encoding the stream broke often. The Wireless LAN cards have a rated bandwidth of 512kbps but much of this is taken up by the protocol functions .One-way QSOs were possible at virtually any encoding speed, and high quality video (P5) was exchanged out to our maximum distance."

Not bad for a couple of laptops and a pair of $30 LAN cards. These LAN cards use spread spec trum and are Part 15 devices (they don 't require a license when used without modification). Since Les and Tom plan to modify these cards with the addition of amplifiers and external antennas , they've decided to participate under the Special Temporary Authorization (STA) of the Tuscon Amateur Packet Radio organization (TAPR) that allows the use of the frequency- hopping method employed by the wireless LAN cards in the amateur band s. After having initial success using the Real Media streams, Les and Tom have transmitted MPEG1 streams at distances of up to three miles using the unmodified Part 15 devices. These streams have included pictures, callsigns, and voice in each test.

So, DHTV experimentation is alive and well in the U.S. Other amateurs are participating in the experimentation and discussion, including Clint Turner, KA7OEI, in Salt Lake City, Utah , and Woody Winstead , KJ4SO, in Raleigh, North Carolina. If this interests you, subscribe to the DHTV re-mailer and start learning about the future of ATV.

I don 't want to leave you with the impression that DHTV is something going on only in the U.S. Quite the contrary- digital ATV experimentation in Europe is several years ahead of us. As early as 1996, the Austrian ATV organization had proposed MPEG 1-based digital ATV as the new standard for the 70centimeter band. This was to try to reduce the constant pressure on spectrum-intensive modes like ATV in countries where the total 70-centimeter band is considerably smaller than what we enjoy in most of the U.S. If you would like to read this proposal, you can find it on the Internet at . It's a very enlightening concept.


Ten years or so later, and we sadly aren't much further.

TAPR recently created a DigtalATV yahoo group. From what I gather DATV is pretty popular in Europe. The problem is it will cost nearly $2,000 to do 1 watt QAM Digital or DVB-S.

Not to practical for a one way transmitter in my book. It has been said that Image communications were never intended to be a mode independent of phone.

With that said, and the early experiments using less expensive 802.11 gear to achieve the same, I'd like to re-introduce that idea.

For those not up to speed, a normal 802.11 signal is 20 MHz wide. This is not a problem on 900 MHz or above, since there is plenty of space and little crowding.

For those not aware, if you use Atheros chip based 802.11 gear, half rate (10 MHz wide), and quarter rate (5 MHz wide) options are available using open source drivers.

And even more interesting is that that within the Atheros chip it is possible for licensed developers to enable a local oscillator generation for a direct conversion radio transceiver. This is not an open function, but irregardless, this is how 802.11 products on 900 MHz (Ubiquiti XR9), and 3 GHz (XR3).

And now 420-450 MHz with a module designed by Doodle Labs.

This is perfect for this type of application, as well as a multitude of other amateur infrastructure applications.

You can read more on the history of ATV and HSMM here:
http://www.qsl.net/kb9mwr/projects/wireless/70cm-ATV-HSMM.html

And what other hams are doing with (muti-mode) 802.11 here:
http://kb9mwr.blogspot.com/search/label/80211use

Saturday, November 19, 2011

Library of AMBE-files

This has been on my to do list for a long time.

About this time last year, Kristoff ON1ARF wrote some excellent open source software.

You can find it here: http://villazeebries.krbonne.net/dstar/voice-announce/

From: http://villazeebries.krbonne.net/hamstuff/?page_id=10
Voice-announcement system on analog repeaters have existed for .. well .. almost forever. D-STAR repeaters, on the other hand, have so-far had this in a very limited way.

The main reason for this is related to the use of the AMBE voice-codec in D-STAR. AMBE-encoders are only available via an external hardware-device (either a chip inside the transceiver or the DVdongle). As this technology is usually not present in a D-STAR repeater, it has up-to-now only been possible to play out a fixed audio-message...

The “dstar voice-announce” package aims to provide additional ways to generate voice-announcement messages on a D-STAR repeater. It is designed to be as flexible as possible, to provide as much choice to the sysops.


By concatenating the .ambe files for “good morning”, “the time is now” “6″ “o’clock”, a complete voice-announcement can be created (also in .ambe format)

Kristoff created a small library of common words using the eSpeek text to speech synthesizer.

I'm not real fond of the voice quality of eSpeak, or Festival/Flite for that matter. So I created an alternate more extensive voice library. Mine contains about 360 words.

Now you don't need a DV Dongle to create system announcements. You just need to install and use Kristoff's ambestream program and download my or his AMBE word library.

You use it like so:

 ambestream -t TEST -v -4 -my KB9MWR -d w1abc.dstargateway.org -p 40000 K9EAM B this.ambe is.ambe a.ambe test.ambe  


Rather than having to specify the path to each ambe word, here is way to use sed to append the full path to the premade AMBE words. In this example I have all my words in /root/words/ambe

 #!/bin/bash  
 #SENTENCE="this.ambe is.ambe a.ambe test.ambe"  
 SENTENCE="this is a test"  
 #  
 # note all forward slashes must be escaped. Just follow the example  
 #  
 #SPEAK=`echo $SENTENCE | sed 's/[^ ][^ ]*/\/root\/words\/ambe\/&/g'`  
 SPEAK=`echo $SENTENCE | sed 's/[^ ][^ ]*/\/root\/words\/ambe\/&.ambe/g'`  
 #  
 #echo $SPEAK  
 ambestream -t TEST -v -4 -my KB9MWR -d w1abc.dstargateway.org -p 40000 K9EAM B $SPEAK  


Please note if you get an error "Error: could not create udp socket! Exiting!" with Kristoff's program, it would be because ipv6 is not installed or enabled. To correct that see:

http://wiki.centos.org/FAQ/CentOS5#head-47912ebdae3b5ac10ff76053ef057c366b421dc4

Monday, October 31, 2011

CisarNet: Italian Cisar Radio Amateur WiFi Network

This just in from IW0SAB, Renzo in Italy:



The National Digital Link Cisar CisarNet (http://wifi.cisar.it), is an ambitious project that is joining much of the Italian region via a backbone digital technology wifi connections to 2.4 and 5.7 GHz, which allows experimentation for radio amateur and any use if needed in an emergency to coordinate and support relief efforts.


They have a 304 km (world record) link on 5.7 GHz. And other impressive wireless links back to other parts of the Hamnet that I have blogged on before.

They have an English wiki that is worth taking a look at.

On the top of this infrastructure, CISAR is activating several services, from voice and video over IP, DSTAR support and conferencing systems.

Thursday, October 20, 2011

802.11 Digital Audio Repeater Linking






Some time back I planted the idea of linking analog repeater together using 802.11/HSMM.

Instead of dedicated link channels usually on 440 MHz, you'd put some of that microwave spectrum to good use.

Since most repeaters are on commercial towers, achieving the required line of site and fresnel zone clearance shouldn't be a problem.

Each repeaters audio would be converted to VOIP using an Asterisk solution or now the plug and play CL-100 controller from CAT. (As seen above)

The advantage is now that is a multi-use link. There will be plenty of bandwidth left over for APRS i-gate traffic, Winlink, etc. Not only that, but other repeater linking could be done on the same 802.11/HSMM microwave backbone.

High speed Multi-Media interconnecting backbones can support radio linking of today as well as of the future.

Large regional and statewide linked repeater systems really should give this idea some consideration.

Thursday, October 13, 2011

Monday, August 29, 2011

Deviation Meter

I hadn't built anything in a while. And a friend mentioned the desire to have something to check for proper deviation on various Echolink and repeater setups.

In a prior blog, Are you narrow or wide?, I covered more of the background.


There is a lot out there on this sort of thing.

http://www.repeater-builder.com/projects/poor-mans-dev-meter/devmeter.html


http://www.repeater-builder.com/rbtip/deviationmeter.html

https://archive.org/stream/73-magazine-1993-08/08_August_1993#page/n23/mode/2up

So I suggested we build this and hook it to a an old dedicated scanner. And after construction we calibrated it against a club IFR-1200 service monitor.

If you are not found of breadboarding, the above 73 article has an etched board available:

http://www.farcircuits.net/test1.htm

Here is a video that my friend made:

You'll be disappointed to know that Radio Shack doesn't carry the 15 vdc panel mount meter anymore.

Monday, July 11, 2011

DUTCH*Star DV Node / WinDV








http://www.blogger.com/img/blank.gif
Fred van Kempen, PA4YBR has written a new Windows program for use with D-Star DVAPs, and GMSK node adapters. It also works with the (blue) DV Dongle, amongst other things.

The DV Node program, (WinDV) will eventually take over most of the "market" currently serviced by DVAR Hotspot, as DVAR has reached the end of its development cycle - the "takeover" by DV Node has been in direct discussion and agreement with Mark McGregor, KB9HKM.


The beauty of his WinDV program is that is supports a combination of several protocols.

DPlus (regular gateways and reflectors) as well as the DExtra protocol used by the Xreflector system. And the newly emerged DCS reflector system.

Also supported are D-STAR Callsign Routing (through ircDDB) and the reporting of GPS positions to the APRS network.

His program should enable more D-Star users to be able access both networks. As currently most D-Star repeaters in DVAP/Dongle users are only able to access the US Trust based network. Where as; homebrew GMSK nodes and repeaters as well as Dongle users using G4KLX Digital Voice package have had access to XRFxxx based reflectors.

Icom stacks/gateways can implement both ircddb and dextra (XRF) linking. I encourage all Icom gateway operators to consider widening the D-Star experience for their users.

I feel Win DV is a great step towards interoperability and hopefully exposing and migrating more users and gateways to a more open source based D-Star infrastructure.

In the future, Fred also notes he plans to develop a version for Linux, and Mac.

I encourage you to check out WinDV today!

Sunday, June 19, 2011

Innovating Makerspaces

Here is something that I wrote for my local ham radio club.

Ham radio operators have long been some of the original open source , Do-It-Yourself (DIY) proponents.

Going back in time, radio stuff was expensive and out of the reach of a lot of hams. So they invented newer and mostly cheaper ways of doing things. They also came up with better ways of doing things because somebody else would see that idea in print and improve upon it. Of course the technology was rather rudimentary, and there was little way to go but up at that point in radio technology calendar.

What most people tend not to think about is the open-source nature of Amateur Radio. While operators most often are seen working in emergency situations, many of the modern conveniences we have today—cell phones, satellites, wireless devices— were developed and tested by radio amateurs.

Decades ago, amateur radio operators were on the forefront of scores of technological innovations, including television, digital communications, solid-state design and cellular networks. The hobby's roots trace back to radio pioneers such as Guglielmo Marconi and FM-inventor Edwin Armstrong.

Well a lot has changed over the years in society and ham radio. Many amateurs have gotten away from these "do-it-yourself" roots. But those types are still out there!

When the economic crisis first started to unfold in 2009, the Wall Street Journal just had an article on how Tinkering is making a comeback amid the economic crisis.

"The American tradition of tinkering -- the spark for inventions from the telephone to the Apple computer -- is making a comeback, boosted by renewed interest in hands-on work amid the economic crisis and falling prices of high-tech tools and materials.

Engineering schools across the country report students are showing an enthusiasm for hands-on work that hasn't been seen in years. Workshops for people to share tools and ideas -- called "hackerspaces" -- are popping up all over the country; there are 124 hackerspaces in the U.S."


In 2005 just shortly before the economic mess stated to unfold, Make Magazine was introduced by O'Reilly Media. It focuses on do it yourself (DIY) and/or DIWO (Do It With Others) projects involving computers, electronics, robotics, metalworking, woodworking and other disciplines.

The magazine was well accepted by engineering and electronics students. And led to the first Maker Faire. An event filled with DIY projects, science, demos.

These "fests" are now in their 6th year, and being held in California, Detroit and New York and many other places.

As mentioned in the Wall Street Journal article, regional groups are popping up all over the place to help support this innovation. These are referred to as Makerspaces/ Hackerspaces. They are places where people with common interests, usually in science, technology, or arts can meet, socialize and collaborate. A Makerspace can be viewed as a community lab, machine shop, or workshop where people of diverse backgrounds can come together to share resources and knowledge to build/make things.

There are two that I know of in our area:

http://milwaukeemakerspace.org/

And closer to home, http://www.dhmn.net/ an Appleton: a group of hacker/maker/software/hardware technology-enamored people.

If you still have a bit of "amateur" in you, I encourage you to branch-out and check these innovative groups out. I think there can be / should be a lot of crossing over and sharing of talents between some ham radio folks and these groups. These are the types of people that need to welcomed with open arms into the hobby.

Friday, May 27, 2011

More graphs

A couple years ago Will Payne, N4YWK was on a quest to graph some of the historic growth of repeaters.



I helped provide some of the data for him. But more recently I wanted to take a look at 70 centimeter ATV growth.



That of course lead to more counting as I wanted to look at the 900 MHz band in light of Alino's announcement that they intend to release a HT capable of 900 MHz. The DJ-G29T.

Link to the FCC OET Papers:
http://tinyurl.com/dj-g29t



I've been exploring 900 MHz since 2008.

I think it's one of the still steadily growing bands out there that can be a lot of fun.

I had no intentions of buying a new HT any time soon, but the DJ-G29T is certainly changing my mind on that. I have wanted a frequency agile radio with a VFO for 900 MHz for a long time. I believe Alinco will be the first ham manufacture of a 900 MHz HT.

Friday, April 1, 2011

Internet Pioneer Paul Baran, W3KAS (SK)



http://www.arrl.org/news/internet-pioneer-paul-baran-w3kas-sk

What I'll add that he mixed his radio interest in by helping found Merticom. A pioneering wireless Internet service that existed from 1995-2003, long before "3G" and wifi..

For more technical info on the Merticom Ricochet Radios you may want to have a look here: http://www.qsl.net/n9zia/metricom/index.html

Friday, March 25, 2011

Bi-directional Amplifier Design

Well it's been a while since I ripped on the ARRL. And since they are doing such a great job, you knew it wouldn't be long before you'd see something so non-professional (amateur) from me again.

from kb9mwr@q...
to w9gig@a...
cc n4qx@a..., n7hpr@t...
date Sun, Jan 16, 2011 at 9:52 PM
subject bi-directional amplifier design help

Hello,

I'd like to help encourage the development/documentation of a bi-directional amplifier for high-speed multi-media applications.

I was prompted when I read the ARRL Homebrew Challenge I said to myself, why encourage something that has already been done.

Since there are more non-part 15 overlapping channels on 3 GHz, 5 GHz and 900 MHz bands I would encourage it to be for either of those bands.

I haven't been able to make much head way in this myself due to a lack of access to the necessary development equipment.

In some of the open source development efforts that I have been part of, a bounty is often posted as a reward for something like this.

I'd like to take the same approach to this, as I am offering $40 to anyone who can document such a design in QEX or the like. I'd also like to suggest that anyone else interested in the development also consider a contribution to the bounty (aka up-the-ante).

The total bounty-pledges of course will help who ever steps forward in their design and development costs.

To clarify, I am not requesting production or kits, just someone who wants the challenge and has the know-how to create a working prototype and will openly document their design in QEX or some other publication.

Would it be possible to get a blurb in QEX magazine to spread the idea out to the more technical crowd?

Thanks,
Steve, KB9MWR


Yeah, you guessed it, zero replies to my request.

And now some commentary on the HR 607 bill that has provisions to auction off a portion of the 70cm band.

I did my part and wrote to my representatives. While it would be a shame to lose this band, the lower half of the band is Very inactive. Around here the only part used for the most-part is 440-450 MHz.

The current band-plan that caves out the lower portion of the band for ATV and isn't bringing any real traffic/ use either.

Seems a shame that we can't setup a decent wireless (emergency) network, other than this pathetic Winlink business. Heck if we can't do it, sounds like that is exactly what the proposed Department of Homeland Security First Responder network is.

Time to move forward, else I have little desire to continue to write letters to try and defend spectrum that will just sit idle as it has been. Use it or lose it..... maybe the ARRL, TAPR and other "leaders" will one day realize they need to step forward and suggest some new ideas for the hobby to help not only "protect" the spectrum, but put it to actual use.

What I am reading is "When All Else Fails" ... we will build our own wireless network. Possibly a wake up call for ham radio?

Tuesday, March 1, 2011

HSMM: 420-430 MHz







It has been a while since I wrote on the idea of HSMM on the 70cm, 420-450 MHz band.

There have been some recent threats to the band with the proposed HR 607 bill.

So my logic to protecting the spectrum available to us, is to try and make better use of what we have, instead of letting it sit idle.

So following that logic, most of the lower part of the 70 centimeter ham band has been fairly idle. This is known as the Amateur TV sub-band (420-430 MHz).

ATV - 421.250 Video - 425.750 Audio
ATV - 427.250 Video - 431.750 Audio
ATV - 434.000 Video - 438.500 Audio
ATV - 439.250 Video - 443.750 Audio

So far there seems to be a fair number of hams interested in 802.11 based networks. But one of the big hurdles is understanding and overcoming the line of site, and other wide-band microwave propagation issues.

I've pointed out that 3 GHz is a great band since you won't be sharing the space with all kinds of other Part 15 unlicensed devices that inevitably lead to a higher noise floors and headaches.

The concept of HSMM on the 70 cm band intrigues me and others greatly because of the non-line-of-site possibilities.

A normal 802.11 channel is 20 MHz wide, but I wrote before that this can be reduced to 5 MHz.

I recently received an email from Jay Parikh with Doodle Labs mentioning he stumbled into this blog and was impressed by it.

He also wrote to bring my attention to a new product introduced by his company that would likely be of interest to the ham community.

Jay, mentions that they have already received a number of inquires from hams on it.

It appears Doodle Labs may be the first to consider offering a true non-line-of-site solution, capable of operation in the 70cm band that could easily fit into unused ATV channels between 420-430 MHz.



Doodle Labs has a new product which should be of interest to any amateur radio operator wishing to experiment with higher-speed digital data in the 70 cm UHF band. The Doodle Labs DL435 420-450 MHz OFDM Transceiver provides high-speed data in channel widths of either 5 or 10 MHz throughout the 70 cm amateur radio band.

The DL435-30 transceiver has a standard 32 bit, 33 MHz miniPCI interface and works perfectly with a Ubiquiti RouterStation. The RouterStation itself is powered via a standard power-over-Ethernet adapter. Note that the DL435-30 does have a fairly high current draw (around 2 amps) when run at http://www.blogger.com/img/blank.giffull RF output power.

The Ubiquit RouterStation or RouterStation Pro can be running either DD-WRT or OpenWrt. Note that currently OpenWrt doesn't allow manual selection of with channel width, so you may wish to try DD-WRT first.

The DL435-30 transceiver is based around the Qualcomm Atheros AR5414A baseband processer and a RF Micro Devices VCO and mixer. The DL435-30 transceiver itself "looks" like a standard 2.4 GHz 802.11g device in software, but the hardware is configured to provide a frequency offset of 2019.5 MHz. For example, if you select "2.442 MHz" in your configuration software the actual operating frequency will be at 422.5 MHz.

There are two channel widths available, 5 and 10 MHz, which are currently only manually selectable using DD-WRT and not OpenWrt. The 5 MHz channel width allows between 1.5-13.5 Mbps and the 10 MHz channel width allows for 3-27 Mbps. The modulation is Orthogonal Frequency-Division Multiplexing (OFDM) with 64 QAM, 16 QAM, QPSK, or BPSK depending on the received power level. The minimum sensitivity is around -97 dBm (for 1 Mbps). "Real-world" throughputs are around 7 Mbps for the 5 MHz channel width and 14 Mbps for the 10 MHz channel width.

Transmit power offset is an additional +10 dBm. So selecting +13 dBm (20 mW) in your software configuration would give a final tx output power of +23 dBm (200 mW). The DL435-30 has an option for using diversity antennas, with one MMCX jack for the main antenna and one MMCX for the auxiliary antenna.

With a 1989.5 MHz frequency offset, a proposed channel plan from Doodle Labs is below.

For 5 MHz BW, Center Freq. = 422.5, 427.5, 432.5 , 437.5, 442.5, 447.5 (For US and AU)
432.5 , 437.5, 442.5, 447.5 (For Canada)
432.5 , 437.5 (For Europe)

For 10 MHz BW, Center Freq. = 427.5, 432.5 , 437.5, 442.5 (For US and AU)
437.5, 442.5 (For Canada)
None (For Europe)

For 20 MHz BW, Center Freq. = 432.5 , 437.5 (For US and AU)
None (For Canada)
None (For Europe)



However, Doodle Lab's normal business model is to work with OEMs. Doodle Labs is not set up to address small quantity purchases. They are also concerned that they may get buried with the support questions. Doodle Labs has approached a few resellers to see if they can do this. But they want to see the demand first before they carry the product. So this is like a chicken and an egg situation.

Sore that reason, I've held off blogging about this exciting new development for some time, but with some limited communications with both Xagyl and Doodle Labs it appears they are at least curious about what kind of amateur market there is. Or at the very least are okay with some inquiries.

{Update 3/20/11}
After a bunch of discussion, Doodle Labs mentioned they planned on releasing a model that specifically covers the ham spectrum. (see below)

So at this point, they are still trying on getting a distributor lined up, and will be in touch with me and others who have contacted them as soon as that is done in approximately two months.

He notes the delay is actually on their side. There are some minor changes that need to be made to the design and their design team is completely swamped at the moment with a few different customer projects.

{Update 6/13/11}
Pre-Production stage. Expected availability is the end of October 2011.

10/11:
http://doodlelabs.com/products-and-services/amateur-bands/420-450-mhz-band-dl435.html

Now if we can just find a OEM interested in selling this. Till then, Doodle Labs will sell factory direct.


Sept 2012:



At the September 2012 DCC in Atlanta, GA, David Bern, W2LNX presented a paper titled  "Experimenting with High Speed Wireless Networking in the 420 MHz Band."


His paper reports on testing two different manufactures of 802.11 mini-PCI cards capable of operation in the 70 cm ATV sub-band using 5 MHz bandwith.

Test applications were a Webcam video streaming program and a file download server program that ran on inexpensive netbook computers.

The test documented in his paper prove a sustainable data rate of  1 Mbit/s over 10 miles.
 


Tuesday, February 22, 2011

Vint Cerf: "Re-Thinking the Internet"

Vint Cerf is recognized as one of the fathers of the internet. (He was a program manager for the U.S. D.A.R.P.A.) He was recently invited back to Stanford where he graduated, to give a speech to future engineering students.

There is a lot of interesting history and things to get you thinking in his presentation.


Pay attention to the end of the presentation for this:

Wireless was absolutely a part of the internet architecture.

I'm uncomfortable with the idea that the emergency network is dependent on a system that is often know not to work during emergencies.

Or If the emergency occurs in an area where there isn't any cellular infrastructure. (Base-stations, back haul)

So I actually like the idea of doing down a different path.

Which is a mesh like thing, that can be ad-hoc.

I also rather like the idea that everything transported in that system is IP based. The part that I like is, it doesn't care how its carried, it doesn't know what its carrying. It could be voice, it could be video, the network is oblivious.

By the way the police and fire departments and EMS today have a lot of trouble communicating. Because their radios have to work at RF. If Instead if we said the whole base is IP.

And if you need to communicate by voice we will use VOIP. And if we have to we will do RF transformations in some portable nodes.

The whole idea is that your compatibility on an end to end to based on VOIP, and not on radio compatibility. We'd have a much more general architecture.

For some reason that unknown reason that obvious fact has been resisted or ignored by the public safety environment.

Thursday, January 27, 2011

New D-Star Developments



Above is a D-Star Support Matrix document that Scott, NS7C compiled. It's a good overview of what works with what.

"With all the various hardware and software options available, I sometimes forget which hardware works with which software."



Just before Christmas I asked on the dstar_digital group about decoding D-Star DTMF. I have found that is way to clumsy to have to handle all control functions using the URCALL fields. (especially when mobile)

About a year ago I had played with trying to decode it. I saw patterns, but wasn't able to define them, and had read that it might not ever be possible to use DTMF on D-Star as some thought it was implemented incorrectly by Icom.

Just after Christmas, Michael, DL1BFF proved this wrong. Turns out after cooking up some code to handle the bit interleaving and FEC processing, the DTMF is there just like the manual says.

To compliment this, Kristoff, ON1ARF has been working on some voice-announcement software.

This includes a wav2ambe tool, that uses a DV-dongle to encode multiple files in sequence to produce one single .dvtool or .ambe file. (useful to generate an announcement "on the fly" based on a sequence of wav-files).

As well as a wavstream tool to stream multiple wav-files in sequence. And ambe2wav - a new tool that can decode one or more AMBE-encoded audio-file (.dvtool or .ambe format) back into a wav-file.

He is also working on generating a predefined AMBE word / letter pack. This will enable D-Star repeaters to be able to concatenate words for announcements without the need for a DV-Dongle attached.

With these two tools, you will be able to setup scripts to speak weather reports and the like, just as hams have done with IRLP.

Also think of custom greetings and queries.

"Welcome Steve to the N9DKH D-Star repeater, the temperate is 67 degrees.".. when you make your first transmission after being idle.

You should also be able to query over the air when your friend was last heard, as well as just about anything else you can think of.

Scott, KI4LKF is still at it. His latest was working in D-Star voice mail.

YRCALL=_ _ _ _ _ _ S0
The above command will Store/create voice mail in the dvtool file x_voicemail.dat
YRCALL=_ _ _ _ _ _ R0
The above command will Recall/playback voice mail from the dvtool file x_voicemail.dat
YRCALL=_ _ _ _ _ _ C0
The above command will Clear/delete voice mail. File x_voicemail.dat will be deleted.
In all cases, the letter x in the file name x_voicemail is the module A,B or C


All very interesting ham developments worth checking out.

Intellectual Property

If you know me or have been reading my blog long enough, you know that I am a proponent of open source concepts.

I remember posting to the Texas A&M Mailing list back in 2007 because I was running into a glut of roadblocks related to Intellectual Property in various projects that I was dabbling with at the time.

"Leaders in the ham radio arena who are to busy beating their own chests touting things like they are the "national association for amateur radio."

These so called leaders need to suggest/ lay some general concepts to steer the hobby to the future.... focus on spreading the importance of the open source concepts in the ham radio arena"


In my last big project the 73 Magazine Index, I realized that its contents will become lost to posterity due to intellectual property issues. A dirty shame....

Interestingly enough, I have noticed that TAPR has grasped the open concept.

They came up with an Open Hardware License, and I just noticed that the DCC DVD I bought was licensed as a Creative Commons 3.0 Share-A-Like work.

Consider this:
TAPR's membership journal publication, the Packet Status Register (PSR) featuring both technical and non-technical articles is an authoritative source for up-to-date user and technical information on digital issues.

Explicit permission is granted to reproduce any materials appearing herein for non-commercial amateur publications provided credit is given to both the author and TAPR...


Yet I just noticed on the front page of the ARRL's site:
Copyright © 2010 American Radio Relay League. Reproduction of material from any ARRL Web page without written permission is strictly prohibited.
Also: http://www.arrl.org/copyright-faqs

I've also noticed that "ARES" is registered trademark of the ARRL and so forth.

I'm sorry if I have not properly denoted all these various trademarks. It's not intentional, it's just an encumberment that I don't have time to keep up with.

The reason I decided to blog about "Intellectual Property" is because my local ham club is in a potential law suit over IP use that could effectively flush this non-profit educational organization of all it's assets.

So I encourage you to think about all this, and how productive or non-productive intellectual property is to the hobby and the world.

Here are some of my favorites:

Revolution OS

The Code Linux

Pirates of Silicon Valley (you can't watch this online due to IP, but it's worth watching)

http://www.fsf.org/

http://www.gnu.org/licenses/gpl.html