Digital, Discussion, Emergency Communications, FLx/FLDigi, Packet

Outbrief – 15 Feb 2015 Digital Workshop

On Saturday, February 14, 2014, the Digital Working Group met along with some other interested parties to discuss the current state of the digital technologies, as well as  try and find a road map for implementation within the PWCARES framework.  After introductions, we went through some presentations.

The Presentations
Rick, KJ4ZIH
  • Evolution from a discussion about “is there a role” for digital in ARES to  clearly there is, especially the farther west in the US you go.
  • Rick has issues getting from his home in Haymarket getting to the repeaters (WWI/OHV) on voice
  • EOC is currently VHF/UHF oriented
  • Two parts of the story – the tools (FLx) and how the PA group is using them (NBEMS)
  • Rick went the route of the SignaLink, but there is software that can do the same thing with your built in sound cards (mostly inexpensive)
  • Similar to a fax machine over a telephone line – stuck pig sounds
  • Multiple ways to move the noise – usually mic and speaker, with the right cables to make the connection

NBEMS

  • Ran through the NBEMS presentation
  • Digital is accurate in the information being transmitted
  • FEC in a number of them protocols
  • Served agencies are moving along the digital message paths
  • NBEMS is an application of the FLx programs
  • Flamp – broadcast message to all
  • Open Source, multi-platform
  • Fldigi – encoder/decoder, with multiple codex
  • Sometimes you need to tweak the time calibration of your soundcard
  • MT-63 is robust, quick, FEC, used by MARS, resistant to noise
  • Good for increased distance performance
  • Olivia is preferred on HF.  Sounds like a flute in the air. Stands out
  • Flmsg is pre-formatted, good fill in the blank ability
  • Text based, self-limiting to 3KB files, with a 3 minute limit for transmission
Derek, KV4SH
HSMM-MESH/Broadband
  • High-speed Mobile Mesh
  • Now called “Broadband hamnet”
  • Autoconfiguation fault tolerant ham radio coverage (part 15/part 97)
  • Because it is mess, it it multipath
  • High bandwidth
  • Transmits IP
  • Not limited by size of file
  • upto 150mb/sec depending on quality
  • Need to flash your router with a new image, configure, put on the air
  • Infrastructure based set up
  • There is the ability to get the hook up on to the Internet…there are issues with doing this
  • LinkSys, Ubuiquiti brand (www.ubnt.com)
  • Under 1 watt of power out of the repeater
  • Until you boost power, you are covered by part 15. Once you boost, you fall into part 97
  • Under part 97, no encryption, no WPA, no SSL/HTTPS/Encrypted chat
  • Coverage up to 10 miles but realistically, much more reduced
  • Emcomm – videos, large images, web cams
  • A discussion of the nuts and bolts of Internet vs Mesh set ups – ssid/esid vs IP address

David, KG4GIY

  • David reviewed the packet and WinLink
  • Packet is still a viable technology, but with a high learning curve.
  • Some masking is done by Outpost, a Windows-based piece of software.
  • Store and forward as well as direct connect. Also has the ability to hopscotch from node-to-node to improve connectivity.
  • Heavy infrastructure requirement, most packet nodes are no longer active.
  • WinLink is a long running, Windows-based message service.
  • Many have had success with it.

The Direction

After the presentations, we made some decisions. To wit:

OS: Windows (for now)

Mode: Ad Hoc

Band: VHF/UHF (for now)

With that as the preconception, the FLx stack of programs makes the most sense to implement. So:

OpMode: MT-63 2KL (2000L)

Freq: 146.475 (ARES VHF 2)

The Concept of Operations

At this point, digital messages are being utilized in experimental mode. While it is desirable to have a digital node at each location, until we are completely comfortable with operation, it may not yet be possible.

Further, these are the identified (but not exclusive) types of messages that could be passed by digital methods.

  1. Bulletins. These are messages that are sent out from NCS regarding the state of the operation, active locations, operational period data, weather updates, etc. that are necessary for all stations but could utilized excessive bandwidth on voice.
  2. POD Supply lists. These are lists that may include equipment and supplies needed at a Point of Distribution, either basics or medicinals.
  3. Low priority messages. These are messages that would take up unnecessary bandwidth on voice but still need to be passed.

While these are not all the types of messages that can, or could be sent by digital, it is a good start.

While we are working through the process and procedures, there are some additional issues we need to keep in the back of our minds.

  • Printers? What is the need for being able to print out these digital messages? Do we need to arrange for access to printers? What sort?
  • Directed Net? Does digital operations require a directed net? How would that operate?
  • Time segments? Would it make more sense to have a time slice management plan instead of a directed net. For example, in any 15 minute segment, the first x period is reserved for priority or emergency traffic, the rest of the period is a free for all?
  • Can fldigi be set to auto select operational mode? If so how so?

Finally, there was a decision to try and set up smaller hands on working groups to configure and test configurations before we take it to the field. There also needs to be a separate effort to create a quick reference guide. This can be managed via the digital list or this site.  If someone would like to volunteer to host a working group, please identify yourself and we will get it on the calendar.

Resources:

Here is a link to the presentations and other information from the working group.

NBEMS

Broadband-hamnet