Transcript Amateur Radio Digital Modes

Amateur Radio Digital Modes
Western Washington Medical Services Team
Brian Daly, WB7OML
EC, King County
History
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March, 1980
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Doug Lockhart, VE7APU, of Vancouver, British Columbia
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Federal Communications Commission approved the transmission of ASCII for
Amateur Radio in the United States
Year and a half after Canadian hams had been authorized to transmit digital
"packet radio“
Developed a device that he called a terminal node controller (TNC)
It worked with a modem to convert ASCII to modulated tones and convert the
demodulated tones back to ASCII
1981  group of hams in Tucson, Arizona, founded the Tucson Amateur
Packet Radio Corporation (TAPR)
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Developed a modified version of the commercial X.25 protocol called Amateur
X.25 (AX.25)
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November, 1983, TAPR released the first TNC in kit form, the TAPR
TNC1
 1984
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a great deal of packet experimentation was done, software for packet bulletin
board systems was developed, and packet radio started becoming more and
more popular all across the U.S. and Canada
What are NOT a digital modes?
Echolink
 IRLP
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So What is this Packet Stuff?
Data that is to be transmitted is collected
in the TNC and sent as bursts, or
packets, of information
 Each packet has:
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The callsign or address of who it's going to
 Who it's coming from
 The route between the two stations
 Data and error checking
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Packet Characteristics
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Packet is an error-detecting mode, which means that it
is capable of communicating error-free information,
including binary data (for images, software
applications, etc)
The problem with packet is that it requires strong,
“quiet” signals at both ends of the path to function
efficiently
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Packet doesn’t tolerate signal fading, noise or interference,
which makes it a poor choice for the chaotic world of HF
HF packet is still used for long-distance traffic
forwarding between some VHF packet networks
(although much of this data is now traveling via the
Internet)
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You’ll also find HF packet in use as part of the APRS
(Automatic Position Reporting System) network.
OSI 7 Layer Model
OSI Layers for Packet
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Network layer
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No network services above the data link layer are required for
direct, keyboard-to-keyboard connections between stations
To provide automated routing of data between stations
(important for the delivery of electronic mail), several network
layer protocols have been developed for use with AX.25
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Any network layer protocol may be used, including the
ubiquitous Internet Protocol
Data link layer: AX.25
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Most prominent among these are NET/ROM, ROSE, and TexNet
AX.25 defines both the physical and data link layers of the
OSI model
Physical layer: modem and radio
Digital Modulation
Transfer a digital bit stream over an
analog bandpass channel
 Analog carrier signal is modulated by a
digital bit stream of either equal length
signals or varying length signals
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What are Digital Modes??
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TOR
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Teleprinting Over Radio
AMTOR - Amateur Teleprinting Over Radio
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FSK mode
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hardly used in the 21st Century
5 bits (as did RTTY)
Cannot transfer extended ASCII or any binary data
PACTOR
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Combines the best aspects of packet (the ability to pass binary data,
for example) and the robust error-free nature of AMTOR.
FSK mode
Standard on modern Multi-Mode TNCs
200 baud operating rate
Huffman compression technique
True binary data transfer capability
Digital Modes
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CLOVER
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G-TOR
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Sophisticated data coding, coupled with complex modulation schemes and
digital processing technology, in an effort to overcome the vagaries of HF
Impressive performance even in the face of weak signals and terrible band
conditions
Proprietary mode developed by HAL
Incorporates a data inter-leaving system that assists in minimizing the effects
of atmospheric noise and has the ability to fix garbled data
Tries to perform all transmissions at 300 baud but drops to 200 baud if
difficulties are encountered and finally to 100 baud
Proprietary mode developed by Kantronics
PSK31
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PSK31 could be viewed as a “high octane cousin of RTTY”
Casual keyboard-to-keyboard operating
It has also been embraced enthusiastically by the QRP community
HF Digital Station
Components of a Packet Station
TNCs
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Dual port 1200/9600 bps operation, standard
Port 1 supports 1200 bps
Port 2 supports 4800, 9600, 19200, 38400 bps with DFSK
modulation
"NEWUSER" mode provides a quick start for packet
newcomers
Large capacity internal mailbox and mail forwarding feature
Multiple user mailbox flashes Mail lamp for up to 10 call
signs
GPS operation mode allows use with APRS® or other
geolocation software
Telemetry functions and Remote Control with two A/D
inputs and two control line outputs
Paging transmit/receive capability -- POCSAG compatible
Digital audio drive control -- set from keyboard or by remote
control
BBS, KISS, XKISS, HOST, TERMINAL, GPS and MODEM
operating modes
"Online" HELP feature
128k memory standard; 512k optional
Modes of Operation
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TNCs can operate in several different modes of
operation:
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Terminal Mode
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Allows you to communicate with your TNC using a 'dumb' RS232 serial terminal, or a terminal emulation software program
running on your PC
Allows you to communicate with your TNC with "English-like"
command strings
AX.25 is run in the TNC
KISS Mode
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The normal AX.25 communication protocol that is built into the
TNC's firmware is essentially bypassed
It is done when a more advanced communication protocol is to
be used (such as Tcp/Ip), or because of limitations of the built in
AX.25 firmware
TNC essentially turns into a simple modem device, transmitting
and receiving raw HDLC packets
Soundcards
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Use the PC
Soundcard DSP as a
modem
 Interface from
computer to radio
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RIGblaster example
Benefit: supports
many different digital
modes via software
What Do I Need for VHF Packet?
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2 meter transceiver
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There is packet activity on 220, 440 and HF, but 2
meters is where most of the action is
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TNC - a terminal node controller
 Cable for connecting the TNC to the radio
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Appropriate mic and speaker jack connectors for
the radio you're going to use
Cable for connecting the TNC to the computer
Packet Radio World
What is a Digipeater?
Digipeater = packet radio digital repeater
 Most digipeaters operate on simplex and
do not receive and transmit
simultaneously
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Receive the digital information, temporarily
store it
 Then turn around and retransmit it
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What can Packet Connect To?
Packet Bulletin Board Systems
(BBS)
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Most cities have one or more packet Bulletin Board Systems, or
BBS
BBSs do two main things:
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BBS is part of a national system of other BBSs, it has the ability
to pass information or messages to any other BBS in the US or
the world
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send and receive personal messages for their local users
send and receive messages or bulletins intended for people locally or
around the world.
This allows you to send messages locally, to someone located in the
next state, or to someone on the other side of the world
BBSs pass local and national bulletins, which are messages
intended to be read by everyone.
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In this way, amateurs can read the latest messages about the ARRL,
AMSAT, TAPR, propagation, DX, and other bulletins on varied topics
NWS BBS
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National Weather Service
Transmits current flood and weather
watches, warnings, and advisories, as well
as the latest public and marine forecasts
and conditions to a West Seattle Bulletin
Board System (BBS) via packet radio
 Amateurs can then receive this information
via packet at 145.010 MHz
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WinLink
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Worldwide network of participating amateur
stations bound together through the use of the
Internet
 By linking with any Winlink station – using HF
PACTOR or VHF/UHF packet – Amateur radio
Operators can exchange e-mail messages and
attachments) with other Winlink-participating
hams, or with anyone with a standard Internet
e-mail address
Winlink Network Architecture
Terminology
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CMS
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The Common Message Servers (CMS) are the common
coordinating server engines central to the Winlink 2000
"star" Network configuration
They coordinate the traffic between the participating network
stations (PMBOs) as well as serving as the e-mail, bulletin
and position reporting interface
All this is done over the Internet in order to make the amateur
radio spectrum more efficient, leaving these radio frequencies
available for end-users
Each of the existing Common Message Servers is a mirror
image of the other, providing continual redundancy should
one of these servers become inoperative
Terminology
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TELNET (TELecommunication NETwork)
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Network protocol used on the Internet or local area network
(LAN) connections
TELPAC (TELnet-PACket Bridge)
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Allows the Winlink 2000 user to employ VHF/UHF Packet
mode with the B2F protocol to take advantage of "last mile"
coverage
Telpac efficiently links conventional AX.25 packet to Winlink
2000's Telnet Servers
Allows the connection of a VHF/UHF modem either directly or
via the AGW Packet Engine with a Paclink or Airmail user
application, and converts the AX.25 Packet to Internet Telnet
for connection to a Winlink Participating Station' s(PMBO)
Telnet Server
Terminology
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PMBO
A Winlink 2000 participating network
mailbox (MBO)
 PMBOs or Radio Message Servers ,
communicate with each other through the
CMS's in a "star" network configuration via
the Internet, and with the end-users over
radio or Internet via Telnet or WEB Browser
Access
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Common Message Server
CMS Status
Radio Message Server
Map of PMBOs
W7IJ
W7BO
Telpac Node
Telpac Limitation
Telpac Gagteway
WL2K’s Telpac (TELnet PACket gateway)
Remote packet user
Simple terminal or FBB compatible
Packet Client (AirMail or Paclink)
Telpac
Windows CPU
AX.25 Packet Radio Link
Conventional Radio
with Packet TNC
Internet link
To a WL2K,
FBB, or JNOS
Telnet Server
Existing WL2K System,
FBB BBS, or JNOS server
Global
Message
Database
Clearing MBO
Internet
Local
Message
Database
Local
Message
Database
Participating MBO
Local
Message
Database
Participating MBO
Participating MBO
FBB
Radio
WL2K TELPAC software
Local
Message
Database
Local
Message
Database
Non-Participating MBO
Non-Participating MBO
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Individual User
Individual User
Telpac Station Status
Winlink Station
Sending an Email
Internet Connection
Telpac Gateways
CMSs
Internet Email
Radio Email
Radio Email without Internet
PMBO Outage
Sample Emcomm Winlink Network
Connecting to Winlink
VHF Winlink
Email via Amateur Radio
(WA7FW-10)
By connecting to the VHF
packet Telpac Node the
ham station may be linked
to the internet to send
and receive e-mails.
Client
Mail
Programs
AirMail
Paclink
HyperTerminal
Antenna
TelPac Node
VHF
Radio
Data
Interface
Ham
Computer
PMBO
Internet
E-mail
Paclink AGW
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Paclink AGW
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Easily configured Winlink 2000 (WL2K) radio E-mail
client that interfaces with most popular E-mail client
programs such as Microsoft Outlook Express
Paclink AGW adds packet radio and Telnet
channels for WL2K connectivity to Outlook Express
Paclink utilizes the AGW Packet Engine to
drive Packet modems, including computer
sound cards
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With one single Paclink application, in front of a
firewall and behind a router, multiple computers
may be enabled with radio email when used with
the Winlink 2000 network system
Paclink Software Stack
Paclink as a Mail Server
Paclink AGW
Setup:
Call signs,
User accts,
Channels,
Connect
scripts
Paclink AGW
Packet/Telnet
Client
Paclink
Postoffice
SMTP Server
POP3 Server
Protocols
WL2K B2F
Keyboard
Multiple Prioritized Channels
Telnet
Telnet
WL2K
Telnet
Servers
Standard E-mail
Client:
(Outlook,
Netscape,
TCP
Eudora, etc)
Address Book:
E-mail addresses
Radio addresses
Tactical addresses
Packet
TCP
AGW
Packet Engine
AX.25
WL2K Packet
PMBOs or
Telpac Nodes
Support for
Multiple E-mail
Clients via LAN
Airmail
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Airmail (mainly for HF Pactor) is a messaging
program (similar to Microsoft Outlook in
appearance) specifically designed for
connection to an HF radio Winlink participating
station
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Developed specifically for sending messages via
HF radio and optimized for low-speed links, not an
adaptation of an ordinary email
Airmail may be used for VHF/UHF Packet
under limited circumstances
 Airmail is required for a radio user to connect
to Winlink over HF radio
Airmail
AirMail can be used to exchange
messages with another ham station,
which is also using AirMail, without using
the internet
 AirMail handles Attachments
 On VHF/UHF Airmail would access a
Winlink Gateway which would have
Telpac installed and running, or one of
the Winlink “RMS” Stations
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Airmail Screen
Sending a Message with Airmail
So what does this all mean?
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MST Use Cases for Packet
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Ability to Send Forms from Hospitals to NCS
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HICS-213 Forms
Medical Supply Lists
SITREPS and Damage Assessment Forms
Patient Tracking Forms
Internet Last Mile Replacement?
NTS Form over Packet
ICS 213 over Packet
Packet Model?
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If we are using
packet to just send
forms, we don’t
necessarily need
email or Winlink
 Simpler packet file
transfers
 Simplex point-topoint
 P-BBS?
Simplex Packet
File Transfers
Airmail Client?
Net
Control
Facilities
Email Model?