Re: Narrow Band Emergency Messages

Steve Hansen

We don't have a high density of digital operators in Maine but our
primary digital comms are with NBEMS and Winlink.

My county, and a couple of neighboring counties, primarily use NBEMS
with VHF (repeater or simplex) and the primary mode is PSK250RC5. This
also works quite well with the statewide linked repeater system which
tends to be a bit noisy at times. When we do use HF, it's Olivia 8/500
for net ops with THOR 50x1 for files. 

With regard to the county I'm in (Knox), we have the EOC plus several
fixed town stations and our hospital that are all equipped with Kenwood
D710s. The computers have NBEMS and Winlink Express. For in-county comms
we use voice and NBEMS if there are operators at both ends or we need
one to many. Winlink Express supports the local packet network as well
as connections to the two Winlink gateways that we have. This provides a
lot of flexibility.

As an example, a portable station might send a flmsg file to a town
station with NBEMS. The town station can attach the flmsg file to a
Winlink Express message and then send it to the county EOC by packet or
to anywhere else via Winlink.

We did an exercise in the spring simulating a tanker-cruise ship
collision. This had a variety of USCG and private fishing vessels
bringing survivors ashore to 5 different harbors. Depending upon
condition, each survivor had to be moved to one of 4 locations (2
hospitals, one resort and a high school). Each harbor station got a list
of survivors (lists varied in quality) and they prepared spreadsheets
that were then sent by fldigi/flmsg. Each of the receiving locations had
to prepare spreadsheets based on what they were supposed to get and the
EOC station consolidated everything and compared the received data with
the ship's manifest. All comms, including inter-county, was simplex VHF.
Finally, the summary spreadsheet was sent to another station by Winlink.
Somehow we managed to account for all 161 passengers in an exercise that
lasted just over an hour.

With regard to mesh networking, we have mesh telephony devices (the
Village Telco MESH Potatoes). These are basically a router with an
analog telephone adapter with mesh firmware. Several counties have these
and we use them where there are base camps. It's Part 15 and everyone
knows how to use a telephone so anyone can use them and the learning
curve is zero. There is a fixed  pair of these for comms between a
warming shelter and a town EOC. 

73, Steve KB1TCE

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