January 2020

January 2020


DEC Bulletin

High Speed Multimedia is ARRL’s terminology. Quoting from the ARRL web site:
“The Amateur Radio bands above 50 MHz can support computer-to-computer communications at speeds high enough to support multimedia applications.

Multimedia in this case refers to voice, data and image communications.

One approach that has been extensively explored is an adaptation of IEEE 802.11 technologies, particularly 802.11b operating in the 2400-2450 MHz band, known as the "Hinternet." Also, under the HSMM umbrella has been an orthogonal frequency division multiplex (OFDM) system developed by John Stephenson, KD6OZH, and tested on the 6-m band.”

The Austin Broadband Hamnet™ (formerly HSMM-MESH™) Special Interest Group have developed hardware and software changes to make use of inexpensive 802.11 wireless computer networking routers under Part-97 of the FCC rules. The terms Broadband Hamnet™ and HSMM-MESH™ are registered trademarks. The network operates on the amateur radio 13cm band (channels 1 through 6). Major changes include extended range 10 – 15 miles with good Line-of-Sight. Privileges are also granted on the 9cm band (3 GHz) and the 5cm band (5 GHz). Automatic address negotiation is employed so routers link automatically, with no user intervention within 5 seconds of coming into RF range of each other. They will also automatically link within 60 seconds from power up. If a BBHN (Broadband Hamnet™) mobile node stays in range of the network, it will transition from node to node automatically. The same as a cell phone will transition from tower to tower. The software uses Optimum Link State Routing (OLSR) firmware. The RF section of the Linksys WRT54GL or Ubiquiti wireless router has been modified so only like modified routers can see each other. They are invisible to all other standard 802.11 routers. A word of caution about using the Linksys WRT54 series routers is that there is not enough memory to sustain another upgrade.

We can also use the Amateur Radio Emergency Data Networking (AREDN) firmware on the Ubiquity, TP Link, Mikrotik, and other routers. The firmware is basically the same so anything done with the BBHN firmware can also be done with the AREDN firmware. The two firmware are not compatible with each other so the network must be one or the other.

What can be done with BBHN/AREDN networking? The answer is anything that can be done on the Internet can be done with the BBHN/AREDN. You can send email, surf the Internet if at least one router in the network is connected to the Internet. The BBHN/AREDN network will allow the transfer/streaming of pictures, amateur digital video (ADV), or transferring files. BBHN/AREDN can also be a source for a VOIP telephone network. During disasters BBHN/AREDN can be used for shelter operations to provide written text to hospitals and pharmacies. It can also provide photographs of trees down, hail damage, power lines down or other infrastructure failure. It could be used to support first responder units in a disaster area. It could provide real time communications support for other responders in field such as ARES® (Amateur Radio Emergency Service®), and CERT (Citizen Emergency Response Team). Public Service Events could be supported such as Races/Runs/Marathons, Parades, Air Shows, Balloon Races. All of this is without the conventional Internet connection.

Currently the BBHN groups in the Austin and Plano, TX areas have extensive networks up and operational for their tornado warning system for the NWS. Las Cruses, NM has around 30-35 ARDEN nodes creating an umbrella over their city now. They have a VOIP telephone network setup and is running D-RATS (D-Star low speed data program). 

Why use the BBHN/AREDN? It is fast. The RF links are around 27- 54 Mbps. To keep everything in perspective we can compare BBHN/AREDN to other daily amateur radio activities. 

– Packet Radio/APRS 0.0012 Mbps

– Pactor III .003 Mbps

– D-Star DD 0.128 Mbps

Home Services

– Fiber optics 2 -15Mbps up-link / 15-25 Mbps down-link

– T1 1.5 Mbps

– DSL up to 1.5 Mbps up-link/ 6 Mbps down-link

– Dialup 0.014 – 0.056 Mbps

We are presently using BBHN to present demonstrations in some local parks. Watch the calendar, Announcements or Special Event pages on this website for location and time. We encourage those interested to come out and see what all can be done with this fantastic technology. For more information about BBHN go to http://broadband-hamnet.org/. For more information about AREDN go to https://www.arednmesh.org

Questions and comments regarding the content of this article are welcome and encouraged. Send an email to the address shown below.

I hope that everyone had a safe and joyful Christmas and have a Happy and Prosperous New Year. 

NOTE: The terms ARES® and Amateur Radio Emergency Service® is both registered trademarks of the American Radio Relay League, Inc. and are used by permission.

Lew Maxwell, KB5HPT
Amateur Radio Emergency Service
DEC, District 6, WTX Section
Email: kb5hpt@arrl.ne
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