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Introduction to Packet Radio Introduction to Packet Radio N6QAD, KI6FAO March 17th 2018 Outline – part I • Digital Modes • Classification • What’s needed to operate with digital modes • Packet Radio • What is it and what is it used for • How the network looks like • Digipeaters and Nodes • Demo • Winlink 2000 • What is it and what is it used for • Winlink in EMCOMM • Demo • APRS • What is it and what is it used for • Demo 2 Outline – part II (next month) • Setting up a Packet station • Assembling a digital station • Configuring a TNC • Configuring a Soundcard with Software modem (also useful for the Fldigi tutorial) • Using Winlink Express and/or Outpost • Software configuration • Sending emails • Using Forms • (maybe Winmor – email on HF) • Using APRSISCE/32 • Software configuration If you bring your station we will • Demo configure it together 3 Digital Modes • Digital Modes • Allow the transmission of digital information via radio • Exchange not only voice but also txt, images, video, files • Require “machines” to process and exchange information Continuous 1 Only discrete levels 0 4 Digital modes – why? • Main Advantages of Digital Transmission • Easy to Store and Manipulate: - Not only voice but also txt images, video, files can be transmitted • Noise Immunity • Allow Long Distance Communication or Lower Power • Transmission errors can be detected easily • Disadvantages of Digital Transmission • Extra Circuitry for Encoding and Decoding 5 Typical Digital Station Store Information: Digital bits need to be TXT, IMAGE, DATA (emails, files converted in audio signals MODULATE AND TRANSMIT etc.) to be fed to the radio : USB on HF MODEM Encode 01001010111 FM on VHF/UHF (different codes for different modes: ASK, FSK, PSK and Baudot, Varicode, ASCII, bitmap) variants 01001010111 TNC RADIO ANTENNA PC 110010001110 RADIO ANTENNA PC SOUND CARD 6 6 Digital Baseband Modulation Examples: CW, Hell PSK31 RTTY, Packet, FT8 7 Digital Modes List (far from complete) ARRL Handbook 2018 Mode Principal Freq. Principal Application Bit rate (bits/sec) Symbol rate (baud) Modulation Error handling ALE HF Data 375 125 8FSK FEC AMTOR-A HF Data 114 114 FSK ARQ AMTOR-B HF Data 114 114 FSK FEC AOR AMBE HF Voice, Data 3600 50 36-QPSK FEC APCO P25 VHF Voice 9600 4,800 4FSK/QPSK FEC Chip64 HF Text 300 300 DBPSK-DSSS FEC CLOVER-II HF Data 62.5-750 31.25 4-(2-16)DPSK/(2-4)DASK FEC/FEC+ARQ CLOVER-2000 HF Data 500-3000 62.5 8-(2-16)DPSK/(2-4)DASK FEC/FEC+ARQ DMR VHF Voice 9600 4800 4FSK/QPSK/C4FM FEC Domino HF Text 31/44/62 7.8/11/15.6 16FSK None DominoEX HF Text 15.63-86.13 3.9-21.5 18FSK None/FEC D-Star (DV) VHF Voice, Data 4800 4800 0.5 GMSK/QPSK/4PSK FEC D-Star (DD) UHF Data 128000 128000 0.5 GMSK/QPSK/4PSK FEC Facsimile HF Image 120 lpm FM, 1500-2300 Hz None FDMDV HF Voice 1450 50 15-QPSK None FSK441 VHF Meteor Scatter 882 441 4FSK None FT8 HF Weak Signal 6.25 8FSK FEC G-TOR HF Data 80/160/240 100/200/300 FSK, 170/200 Hz shift FEC + ARQ Hellschreiber (Field) HF Text 122.5 122.5 ASK None JT6M 6m Meteor Scatter 116.8 21.53 44FSK None JT65 V/UHF Moonbounce 16.1 2.7 65FSK FEC MFSK16 HF Text, Data 62.5 15.625 16FSK FEC MT63 HF Text 320/640/1280 5/10/2020 64-DPSK FEC Olivia HF Text 78.13/156.25 15.63/31.25 32-FSK FEC Packet (Bell202) VHF Data, Winlink 1200 1200 FSK ARQ PACTOR-I HF Data, Winlink 100/200 100/200 FSK, 200 Hz shift ARQ PACTOR-II HF Data, Winlink 200-800 100 2-DBPSK/PI-4DQPSK/8,16DPSK FEC + ARQ PACTOR-III HF Data, Winlink 200-3600 100 (2-18)-DBPSK/DQPSK FEC + ARQ PSK31 HF Text 31.25 31.25 BPSK None QPSK31 HF Text 62.5 31.25 QPSK FEC PSK63/125 HF Text 62.5/125 62.5/125 BPSK None QPSK62/126 HF Text 125/250 62.5/125 QPSK FEC Q15X25 HF Data 2500 83.33 15-QPSK FEC + ARQ RTTY (Baudot) HF Text 45.45 45.45 FSK, 170 Hz shift None STTV (traditional) HF Image 120-line B/W FM, 1200-2300 Hz None STTV Martin M1 HF Image 240-line RGB FM, 1200-2300 Hz None STTV Scottie S1 HF Image 240-line RGB FM, 1200-2300 Hz None System Fusion VHF Voice, Data 9600 4800 4FSK/QPSK/C4FM FEC 8 Throb HF Text 1/2/2004 9FSK/2-9FSK None WINMOR HF Winlink 62.5-3750 31.25/62.5 (1-15)-QPSK/16QAM/4FSK FEC + ARQ Classification ….. or simplification (not very precise) …..or more an attempt to reduce confusion • Keyboard to keyboard Modes (Txt) • Typically on HF • Mostly Soundcard • Typical software required: FLDigi • Keyboard to keyboard Structured Modes (Week Signal, EME) • Typically on VHF/UHF use error correction (FEC) • Soundcard • Typical software required: WSJT-X…. • SSTV(Images) • Typically on HF but also on VHF (ISS 145.800 MHz FM) • Soundcard (doesn’t use digital modulation) • Typical software required: MMSSTV • Networking Modes (Txt, Data) • On HF and VHF use error correction (FEC + ARQ) • Mostly TNC or a Software modem and a Soundcard • Typical software required: Putty, Outpost, Winlink Express 9 What is packet radio? • Probably the most popular networking mode on VHF • Transmitted information is received “error free”…. • Built on the AX.25 protocol • Data stream into bite-sized packets (payload 256 bytes ASCII code) • Sends a “packet” of data (envelope + payload) at a time • On VHF/UHF, typically operates at 1200 baud (AFSK on FM) or 9600 baud (G3RUH FSK) How does a packet look like? 10 What can we do with Packet radio? 11 What can we do with Packet radio? Full-service BBSs and nodes often use another frequency to exchange large amounts of data This is known as the “backbone” Internet can also be used to link BBSs & nodes 12 What if we cannot reach another station? Packet stations can operate as Digipeaters or Nodes (KA, K) 13 Resources in the area Keyboard to Keyboard Freq. 144.35, 145.03, 145.05 MHz Freq. MHz Digipeater KA-Node BBS RMS Server Location 145.63 W6SCF-7 (KBLKM) W6SCF-6 W6SCF-10 South Skyline (BLKMTN) 145.63 * KE6AFE-6 KE6AFE-7 K6AFE-10 Crystal Peak 145.63 * K2RDX-10 San Jose 145.63 * W6JWS-3 Castle Rock Ridge 145.63 ** K6IXA-5 K6IXA-10 Mariposa (OSO) 145.63 ** KC6SSM-10 Berkeley 145.63*** N6QAD-6 N6QAD-7 N6QAD-1 Cuesta La Honda (CUSTLH) 145.05 K6FB-7 K6FB-2 Las Cumbres 145.09 N0ARY-1 Mt. Umunhum 145.09 N6ZX-4 Skyline Blvd 145.73 W2XSC-1 (EP) Crystal Peak *via W6SCF-7, **via W6SCF-7,KE6AFE-7, *** rarely on 14 OK let’s try! DEMO 1 • UNPROTO packets conversation • PBBS – N6QAD-1 store and retrieve a message • Using digipeaters • How does a BBS look like? (not live) 15 Winlink 2000 an integrated solution for email exchange via radio • Integrated Solution (RF+Internet) • VHF, HF • Several Modes: Packet, Winmor, Pactor, Telnet • Support also Peer-to-peer • Optimized for EMCOMM 16 Winlink 2000 CMS RMS (gateways ) Client (you) 17 Software • Two main email client • Winlink Express - Specifically designed for Winlink (allow to exploit all Winlink features) • Outpost - Packet only but for that more versatile than Winlink Express (BBS) 18 OK let’s try! DEMO 2 • Winlink Express • Telnet (if we have internet) • Packet • Packet Peer to Peer • Winlink Forms 19 Automatic Packet Reporting System What is APRS? •Automatic Packet Reporting System • also known as Automatic Position Reporting System (not accurate) • can be used for more than just beaconing a station position •Based on AX.25 packet protocol • Real-time information distribution system •Packets can move through RF or the Internet •Stations, objects, and data can be displayed on a map 20 Automatic Packet Reporting System What can you do with APRS? • Tracking • cars, trucks, boats, balloons, airplanes • Locate resources (digipeaters) • Weather data reporting • Short messages and emails • Use for: Public service, Disaster, Search And Rescue Marathons, Races, Other Events. APRS.fi 21 Automatic Packet Reporting System How does it works? • Stations transmit their positions • Stations transmit objects • Most operations are on 144.390 MHz • Digipeaters repeat positions and objects • I-Gates send positions and objects to APRS-IS Digipeater (station with TNC) Internet Packet Station + GPS Unit APRS-IS Packet Station + GPS Unit IGate (station with TNC and Internet connection) How many times your position gets broadcast? Digipeater paths • Digipeaterpaths – determine how many “hops” your packet will make • Suggested paths • Mobile: WIDE1-1,WIDE2-1 Example: WIDE1-1,WIDE2-2 • Base: WIDE2-2 • Don’t abuse the system 23 OK let’s try! DEMO 3 • APRSIS-CE • Tracking • Messaging • APRSDROID • APRS.fi 24 Summary of what is needed for packet operation • VHF/UHF Radio • PC/Laptop (software is open source) • TNC or a Soundcard • Kantronics KPC-3+ (~$200 HRO, ~$120 ebay) • TNC-X (~$80+$20 Bluetooth) • Signalink (~$130, ~$75 ebay) • Rigblaster (~$200) • Cables (radios have different data ports so different cables are needed for different models – packetradio.com) • GPS unit (APRS only) • Maybe a cellphone • Byonics GPS5 (~$70) 25 Passcodes • Winlink account: Nothing to be done. The account is automatically created the first time you send an email • APRS passcode (valid for all clients): send an e-mail to [email protected] including your name, callsign, and the fact that you need a passcode for APRSISCE/32 26 Acknowledgments and references • ARRL Handbook 2018 • Introduction to Packet Radio by Larry Kenney, WB9LOZ • AX.25 Link Access Protocol for Amateur Packet Radio • Santa Clara County ARES/RACES Packet Type III (course material) • Tippecanoe County ARES – Packet Workshop Presentation 2012 • Packet Radio Overview – presentation by Matt VK2RQ • RMS Express - Winlink Global Radio Email - Currie (commacademy.org) • Introduction to APRS - W9RXR 27 Backup Section Winlink Express usage step-by-step 28 Winlink Express Main Screen Begin Connection connection Mode .Multiple call signs Standard Folders Personal message folders Contacts address book Composing A Message Post to Outbox New Message Button Click “To” or “CC” for contacts Multiple Request recipient Read s and CC Receipt File attachment s Pending Message In Outbox Open Session Once a message has been posted to the outbox, it remains there until a transfer session has been opened and started.
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