you - Free and Open Source Software

PACKET
Brian Lloyd WB6RON
19200 Tilford Way
Germantown MD 20874
Packet in Emergency
Communications
Ask almost any packeteer, and
they are likely 10 tell you that
packet radio is a natural mooe lor
emergency and public service
communications. Upon asking
why, the answer may be, " It is
error free." or , " Many people can
share a channel." These responses.
however, do not reflect
an understanding of emergency
communications needs. They're
impor1anl. but they're not sufficent.
t have been involved in two
large Simulated Emergency r ests
(SETs) performed by the National
D isaster Medical Service
(NOMS). These events were very
enlightening. The lirst fest flopped
monumentally as far as packet radio
was concerned. Our group
was able 10 pass only two or three
pieces of traffic the entire day.
There were several problems:
t . A critical digipeater failed.
2. Many of the operators didn't
really know packet operations.
3. Many of the packet stations had
not been tested beforehand.
4. There were no in-place procedures.
5. Connected-mode AX .25 did
not facilitate the free flow of
messages from one point to
many points or from many
outlying points to a single central
collection point.
The second SET was a success
lor packet radio largely due to the
efforts of Bob Bruninga WB4APR.
Bob noticed that most of the messages
were short and would lit into
a single packet. Inspired by this
observation, he wrote a program
for the Commodore-64 that sends
each message as an unconnected
packet and receives acknowledgments
the same way. In other
words, this protocol sent each
message as a "datagram" using
the unconnected mode of the
TNC. Bob also gathered together
the equipment and operators
ahead of time to ensure that the
stations worked and that the operators
knew how to use the sonware
and equipment. Bob's sue-
Numbel' 22 on your FeedbK'k card
Latest in Digital Hamming
cessful experience with this SET
later proved useful in moving a
large amount of health-andwelfare
information for a re al
emergency.
About a year ago there was a
serious train wreck in Baltimore,
Maryland, involving a large number
of injured and significant loss
of life. Again Bob Bruninga was on
the scene. Bob had a complete
battery-operated station in a briefcase,
wh ich he quickly put to work
mo ving informat ion into the
W31WI BSS. Tom Clark W3lWI removed
the information locally and
redistributed it via VHF and HF.
All the traffic flowed efficiently and
broken down. It's usually more
efficient to help socre up existing
emergency communications
than to offer a new and unfamiliar
system 10 the responsible authorities.
The key to successful emergency
and public service packet cornmunications
is careful planning
and preparation. Make attempts
to establish guidelines and procedures
in conjunction with the local
NTS, ARES, RACES, Civil Defense,
Red Cross. City, County,
State, and Federal emergency
planners. Without this, it's VERY
difficult to provide USEFUL service
during an emergency . It's too
late to begin at the time of the
emergency.
The following few paragraphs
are some ideas on imp roving
emergency packet communications.
"(Bob WB4APR's)
protocol sent each message
as a " datagram" using
the unconnected mode
of the TNC. rr
in a timely manner. Here, the coonected
mode 01 AX.25 was quite
useful since, essentially, only two
packet stations took part.
Looking at these cases more
closely, note several common factors
contributing to packet radio's
success here:
1. Trained operators;
2. Pretested and preconfigured
equipment; and
3. A knowledge of the type of communications
so an appropriate
mode can be selected.
Many hams often ignore the
third element. Sometimes voice is
the best way to move information;
at other times the telephone. A
ham isn't necessarily "cheati ng"
by using the phone or removing
his fingers from the keyboard and
talking into a mike.
Ha ms tend 10 be communications
specialists. Many understand
both voice and data communications.
Ma ny are teenntceuv
qualified and can use
their knowledge and equipment
to enhance communications
when existing emergency communicatio
ns are overloaded or
High-level Network Services
The packet community should
take a great interest in Bob's unconnected
datagram program for
the C-64. It's a first attempt to
tailor a system to disaster communications
needs. It worked where
a BSS would have lailed meerably.
Bob's success reveals the
general need to define the reo
quired kinds of packet communications,
and thu s the software
needed .
Fully-Automatic Mall System
This would deliver mail to the
destination system and perhaps
even print a copy of the message.
This would be a godsend in an
emergency situation. The operator
need only tear off the message
and hand it to the recipient. The
originator addresses the mail to
user destination. The networking
protocol structure would release
th e operato r from th e need to
know the message routing.
cipient without a great deal of operator
intervention. Simply tell the
system where to put the file and let
it do the rest of the work.
Keyboard-to-Keyboard Mode
This would allow chatting or ex­
Changing timely information.
All of these services should be
able to run concurrently. The operator
should be able to send mail,
receive mail, send files, receive
files, and carry on a aso with
several stations concurrently. It
should be lully automatic so that
the operator need only initiate the
desired operation while the network
does the rest of the work.
Since the data is digital, packet
radio has the ability to move information
other than ASCII text.
Imagine the service offered by
carrying a ponable packet station
to the site of a disaster, capturing
an image of the damage, storing it
inside the computer, and then fi·
nauy translerring the digital image
to the approp riate agency via
packet radio. This is now possible!
Another area of interest is using
digital voice messages. A fast
packet network can move voice as
well as other data. Current technology
allows transmission of fully
u nd ersta nd able voice dat a at
2400 bps, or telephone quality
voice at 9600 bps.
How about facsimile? Most of
the fax units manufactured tooay
are digital units designed to move
data over a telephone line using a
modem. Why not pipe that data
stream into the packet network to
transfer the doc uments?
Packet radio has many possibilities
for emergency, public service,
and even just-tor-tun use.
Evaluate the need and then apply
the appropriate technology. Don't
try to replace HTs and repeaters
with a packet station-the HT will
win. On the other hand, there are
many applications lor packet
where voice can't serve. Pursue
those and let packet radio take its
unique place in emergency and
public service communications.
TCPIIP on Packet with net.exe
The previously promised review
of the KA90 TCpnp networking
code for the IBM-PC, Commodore
Am iga, and Apple Macintosh,
dovetails nicely wit h the " wish
ust" above .
The TCPIlP package written by
Phil Karn KA90 is a compreheo­
Automatic File Transfer
s've implementation of the Inter­
Protocot
net Protocol Suite used commer..
Like the m ail service, this dally and by the Department 01
should be able to deliver any type Defense for connecting different
of file-binary or ASCI1-to the re- co mputers together using dn-
73 Amateur Radio • April, 1988 67