1. Amateur Radio Digital Modes
Western Washington Medical Services Team
Brian Daly, WB7OML
EC, King County

2. History
March, 1980
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“
Doug Lockhart, VE7APU, of Vancouver, British Columbia
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)
Developed a modified version of the commercial X.25 protocol called Amateur X.25 (AX.25)
November, 1983, TAPR released the first TNC in kit form, the TAPR TNC1
1984
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

3. What are NOT a digital modes?
Echolink
IRLP

4. 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:
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

5. Packet Characteristics
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
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)
You’ll also find HF packet in use as part of the APRS (Automatic Position Reporting System) network.

6. OSI 7 Layer Model

7. OSI Layers for Packet Network layer Data link layer: AX.25
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
Most prominent among these are NET/ROM, ROSE, and TexNet
Any network layer protocol may be used, including the ubiquitous Internet Protocol
Data link layer: AX.25
AX.25 defines both the physical and data link layers of the OSI model
Physical layer: modem and radio

8. 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

9. What are Digital Modes?? TOR AMTOR - Amateur Teleprinting Over Radio
FSK mode
hardly used in the 21st Century
5 bits (as did RTTY)
Cannot transfer extended ASCII or any binary data
PACTOR
Combines the best aspects of packet (the ability to pass binary data, for example) and the robust error-free nature of AMTOR.
Standard on modern Multi-Mode TNCs
200 baud operating rate
Huffman compression technique
True binary data transfer capability

10. Digital Modes CLOVER G-TOR PSK31
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
G-TOR
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
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

11. HF Digital Station

12. Components of a Packet Station

13. TNCs Dual port 1200/9600 bps operation, standard
Port 1 supports 1200 bps
Port 2 supports 4800, 9600, 19200, 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

14. Modes of Operation
TNCs can operate in several different modes of operation:
Terminal Mode
Allows you to communicate with your TNC using a 'dumb' RS-232 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
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

15. Soundcards Use the PC Soundcard DSP as a modem
Interface from computer to radio
RIGblaster example
Benefit: supports many different digital modes via software

16. What Do I Need for VHF Packet?
2 meter transceiver
There is packet activity on 220, 440 and HF, but 2 meters is where most of the action is
TNC - a terminal node controller
Cable for connecting the TNC to the radio
Appropriate mic and speaker jack connectors for the radio you're going to use
Cable for connecting the TNC to the computer

17. Packet Radio World

18. What is a Digipeater? Digipeater = packet radio digital repeater
Most digipeaters operate on simplex and do not receive and transmit simultaneously
Receive the digital information, temporarily store it
Then turn around and retransmit it

19. What can Packet Connect To?

20. Packet Bulletin Board Systems (BBS)
Most cities have one or more packet Bulletin Board Systems, or BBS
BBSs do two main things:
send and receive personal messages for their local users
send and receive messages or bulletins intended for people locally or around the world.
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
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.
In this way, amateurs can read the latest messages about the ARRL, AMSAT, TAPR, propagation, DX, and other bulletins on varied topics

21. NWS BBS 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 MHz

22. WinLink
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 messages and attachments) with other Winlink-participating hams, or with anyone with a standard Internet address

23. Winlink Network Architecture

24. Terminology
CMS
The Common Message Servers (CMS) are the common coordinating server engines central to the Winlink "star" Network configuration
They coordinate the traffic between the participating network stations (PMBOs) as well as serving as the , 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

25. Terminology TELNET (TELecommunication NETwork)
Network protocol used on the Internet or local area network (LAN) connections
TELPAC (TELnet-PACket Bridge)
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

26. Terminology 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

27. Common Message Server

28. CMS Status

29. Radio Message Server

30. Map of PMBOs
W7IJ
W7BO

31. Telpac Node

32. Telpac Limitation

33. Telpac Gagteway

34. Telpac Station Status

35. Winlink Station

36. Sending an

37. Internet Connection

38. Telpac Gateways

39. CMSs

40. Internet

41. Radio

42. Radio Email without Internet

43. PMBO Outage

44. Sample Emcomm Winlink Network

45. Connecting to Winlink

46. VHF Winlink

47. Email via Amateur Radio
(WA7FW-10)
Antenna
By connecting to the VHF packet Telpac Node the ham station may be linked to the internet to send and receive s.
TelPac Node
VHF
Radio
PMBO
Data
Interface
Client
Mail
Programs
AirMail
Ham
Computer
Internet
Paclink
HyperTerminal

48. Paclink AGW Paclink AGW
Easily configured Winlink 2000 (WL2K) radio client that interfaces with most popular 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
With one single Paclink application, in front of a firewall and behind a router, multiple computers may be enabled with radio when used with the Winlink 2000 network system

49. Paclink Software Stack

50. Paclink as a Mail Server

51. Paclink AGW

52. Airmail
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
Developed specifically for sending messages via HF radio and optimized for low-speed links, not an adaptation of an ordinary
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

53. 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

54. Airmail Screen

55. Sending a Message with Airmail

56. So what does this all mean?
MST Use Cases for Packet
Ability to Send Forms from Hospitals to NCS
HICS-213 Forms
Medical Supply Lists
SITREPS and Damage Assessment Forms
Patient Tracking Forms
Internet Last Mile Replacement?

57. NTS Form over Packet

58. ICS 213 over Packet

59. Packet Model?
If we are using packet to just send forms, we don’t necessarily need or Winlink
Simpler packet file transfers
Simplex point-to-point
P-BBS?
Simplex Packet
File Transfers
Airmail Client?
Net
Control
Facilities

60. Model?