Sunday, February 15, 2009

Flexibility of a HSMM network

KE7FTE, N7QQU and W9ERT show us the "drag and drop" flexibility of a HSMM platform. Offering reliable exchange of large image files, email, word-processing and other files that emergency responders and served agencies find invaluable.

The video does show what HSMM networks can provide for ARES. It should be clarified that this drag and drop flexibility is not exclusive to D-Star. It's a network file sharing protocol being employed between the laptops being used. Any TCP/IP based network can support this.

Yessj What's the range on this thing? It looks quite similar to a wireless peer to peer lan!


One big difference HAMS can use greater power with a upside of distance and robustness. Hams can use up to 1500 watts of power. Where your local wireless network is measured in millawatts to watts. With high gain antennas and lots of power ranges can exceed 50-80 miles. And that's peer to peer! Try that with your wireless LAN! Idea is this can provide emergency backbone for a LAN that is down in an emergency. Not super fast, just robust and proven!

Above are some of the youtube video comments. W7NWH is trying to make this pricey D-Star sound like it's fundamentally superior to common wifi. Yes hams can run more power, but that likely won't accomplish much more. Microwave propagation is microwave propagation. Height is the key item. If you don't have it, the 10 watt D-Star radios at 1.2 GHz won't yield much better paths than the under 1 watt paths that you could do with wifi. I don't know of any 1.2 GHz amplifiers to run more than the stock Icom ID-1 let you anyway. They have been several well publicized examples of 20-30 mile 802.11 links, and one 72 mile path!... One with a ham twist was published in the July 2005 QST, titled, "IEEE 802.11 Experiments In Virginias Shenandoah Valley."

One thing I've noticed is that command posts love telephones and fax machines. Pictured above you see an $30 analog telephone adapter. Talk about seamless to the emergency manager!

Another interesting and smart idea when it comes to repeater linking is to use analog radio adapters and link the repeaters over your HSMM backbone. Most repeaters are on decent tower sites already so linking such sites over microwave HSMM links should be very feasible. Now your linking channel is not just capable of voice, but can act as a high-speed back bone.

IRLP and Echolink linking are pretty prominent and well understood. In many cases there may be multiple repeaters in the same geographic area all linked (maybe even semi-permanently) using such common VOIP networks.

With HSMM backbones you can off-network link these. This is very emcomm friendly in the even a backhoe takes out internet to most of an area.

Thursday, February 5, 2009

Minneapolis Wi-Fi network aids rescuers - bridge collapse

So the real question is when are ARES/RACES groups going to realize its time to implement this using products like the Ubiquiti NS3/XR3 on 3 GHz, the lower half (2.3 GHz) of the 2.4 GHz ham band, the 5.8 GHz band, or even 900 MHz with something like the XR9.

Ubiquiti's AirOS firmware as well as popular third party firmware such as DD-WRT all now have mesh networking protocols like WDS (Wireless Distribution System) built in.

Mesh protocols are designed for self-healing networks that are able to load balance WAN (wide area network) access. They also combine some of the ideas contained in the Radio Shortest Path First protocol. If the you are not up to par on the dynamics of mesh networks, here are a few links: An ad hoc wireless mesh routing daemon
You may also wish to read the article by John, K8OCL, titled "New High-Speed Multi-Media Radio Mesh Networking," printed in the Fall 2008 CQ-VHF magazine.

Mesh is very powerful stuff. And when you throw SIP / Asterisk based telephony on top of it, you have an instant voice system. Just plug in an IP phone or analog telephone adapter. Now not only can you exchange large image files, email, word-processing and other files that emergency responders and served agencies find invaluable. You can also pick up a phone or (seamlessly) bridge existing ones that are dead due to a land-line failure... etc.


Emergency communications offer the greatest opportunity for Radio Local Area Network (RLAN) technology to excel and for amateurs to push the envelope in the public service sector, using this technology....

Another good read is the Winter 2005 issue of CQ-VHF. John, K8OCL wrote a HSMM column on a HSMM portable setup for EmComm organizations.

Tuesday, February 3, 2009

TAPR Explained

TAPR is explained in by Steve Bible, N7HPR (TAPR’s vice president) in the June 13, 2008 RAIN report.

Have you developed a digital project but don’t know how to get some exposure or funding for it?

Try TAPR. A community that provides leadership and resources to radio amateurs for the purpose of advancing the radio art.

Steve Bible, N7HPR is TAPR’s vice president...

“One thing to keep in mind is that TAPR isn’t brick and mortar, doesn’t have paid staff running around with white labs coats, or jeans and a tee-shirt, which-ever vision that you have.”

“In terms of you creating a project, what TAPR does is very much like our mission statement says that we provide leadership and resources for advancing the amateur radio art.”

“If you have a project that you would like to bring to the community, and the community being amateur radio as a whole. What TAPR can do is not so much provide you a body or person, but provide you a forum or community to flush out your design....”

“What you bring is the expertise, the design and effort going into creating the project. Where TAPR can come in and help you with is the monetary side of it.”

“When it comes time to manufacturing the kit, you may want to make a kit where it’s a kit of parts, or you may want it contract manufactured like this, and this is where we are going to have to talk to you one on one with respect to contract manufacturing. But if your going to do a kit, what we’d ask that you’d do is you’d put the kit together and then ship those off to the TAPR office. And then TAPR would be the store front and sell them. Again TAPR would buy all the piece parts, but you’d be the one winding the torriods, putting parts in to bags....”

“How do you go about getting your project into the TAPR store front? What you do is write a proposal. There is no set format for this proposal, we don‘t really have a form. Suffice to say, that you describe the project and what benefit it has to the community . You kinda put a little bit of business plan into there. Here’s how much it’s going to cost to build the Alpha’s, the Beta’s here’s kind of the plan cost on how to go into production, how many can be sold.”

For what its worth, I thought that was helpful. I never really understood TAPR. I knew what the name stood for, so I always assumed they were the voice representing the digital aspects of the hobby.

I guess I can stop grumbling that they don't do anything in that arena. Now I know why, that's not their department apparently. The TAPR "resource" as described in the podcast is also very important, so I'm glad TAPR exists at least for this. But I also feel we need some leaders to help ham radio evolve. It's a shame, because that's an area the ARRL surely doesn't seem very interested in.

Sunday, February 1, 2009

Ham radio in a Diet Mountain Dew commercial

There is an older Diet Mountain Dew commercial that starts off with a man walking in a valley with a powerful thunderstorm in progress. He sees 5 women doing rather absurd things. The first pair of women are fencing each other (without face guards, so that you can easily tell that they're women). The 3rd woman, the point of this message, is operating a variety of radio equipment. The last 2 women are standing on rather tall stilts. The man comments, "Aren't you afraid you're going to be struck by lightning..." and the man promptly gets zapped by a bolt. Then a fact is posted, "Lightning strikes men 4 times more often than women." There's also a bit with the "announcer".

Pictured: Top left: Swan transceiver. Bottom left: Hammerlund receiver. Middle: Swan power supply. Top right: Gonset AM 2 meter transceiver. Bottom right:Gonset linear amplifier. Microphone: RCA Desktop.