LDS ECS Training 17 March 2012 Digital Communications Gary J Takis – K7GJT/NNN0GJT
Mtn View Ward, Vancouver Stake Clark County ARES/RACES EC/RO N-MC MARS NCS SHARES
1 Lot’s of information to cover!
Kind of like… “trying to drink from a firehose”
That’s ok… it will be on the C.A.R.S. website!
Digital Communications 2 How is it different than voice? Digital Communications 3 Subjects to cover • Amateur Radio Digital Mode History • Amateur Radio Digital Modes • Transmission Coding Schemes • Two Basic Digital Technologies (TNC & Soundcard) • ‘TNC’ Technology, Modes & Software • ‘Soundcard’ Technology, Modes & Software • PACKET • APRS • Winlink 2000 system • High Speed Multi-Media Mesh (HSMM-Mesh) Digital Communications 4
Amateur Radio Digital Mode History
• The ‘Original Digital’ mode
– Presence or absence of carrier (1, 0, 1, 0, 1, etc.)
– CW!
Digital Communications 5 Amateur HF Radio Digital Mode History
• Started as Mechanical Hardware Specific – 1849 Landline based teleprinter operations began – 1920 Rudolf Hell invented Hellschreiber – 1930’s RTTY (Radio TeleTYpe) [Military RATT/SCRT] • 1980’s started computerizing the RTTY signals • Prior to 1995 the only ‘legal’ HF digital mode that was authorized by the FCC were those that used the standard Baudot codes; e.g. RTTY
Digital Communications 6 Amateur HF Radio Digital Mode History
• In 1995, the FCC opened to door to other modes (ASCII based) and declared that any new mode coding were legal as long as they were published in the public domain.
• … and the “Barn Door” opened!
Digital Communications 7 Amateur VHF/UHF Digital Mode History • Been around since the mid-1960's • First seen on the amateur bands in 1978 through research done in Montreal, Canada in 1978 • VADCG TNC board in 1980 (TNC-1) • TAPR TNC board in '84-'85 (TNC-2) • The PACKET radio revolution ignited when TAPR sold over a thousand TNC-2 kits • 1969 – ARPANET & 1970 ALOHANET
Digital Communications 8 Digital Messaging Systems
• Station-to-Station (Peer to Peer)
• Routed point-to-point (Hierarchical Addressing)
• Bulletin Board (BBS)
• Global (Winlink eMail)
Digital Communications 9 Digits to Tones - then - Tones to Digits
Digital Communications 10 Amateur Radio Digital Modes
Digital Communications 11 Transmission Coding Schemes
• CW – Continuous Wave (on-off) • AFSK – Audio Frequency Shift Keying • BPSK – Binary Phase Shift Keying • FSK – Frequency shift Keying • MPSK - Multiple Phase Shift Keying • PSK - Phase Shift Keying • QPSK - Quadrature Phase Shift Keying
Digital Communications 12 Two Basic Digital Methods • Terminal Node Controller (TNC) – Hardware based – External ‘smart box’ converter for ‘digits-to-tones’ and ‘tones to-digits’ – Not inexpensive
• Soundcard – Software based – External or Internal PC microprocessor converter for ‘digits-to-tones’ and ‘tones to-digits’
Digital Communications 13 External TNC Technology
• TNC (Terminal Node Controller )
– Typically external to PC
– Many mfg’s (SCS, Kantronics, Timewave/AEA, etc.)
– Some have Digital Signal Processing (DSP) built-in
Digital Communications 14 External TNC Devices SCS, AEA/Timewave, Kantronics, etc.
Digital Communications 15 External TNC Modes • PACTOR I, II, III & IV • AMTOR • RTTY • PSK31 • CW • PACKET (HF & U/VHF • NAVTEX • TDM • Robust PACKET
Digital Communications 16 External TNC Software Generic SCS Specific • Alpha • NCWinPTC • Airmail • NCWinPTC Term – PACKET/PACTOR • EzTransfer • Paclink • SCS Mail – PACKET/PACTOR • PAXON AEA/Timewave Specific • RMS Express • PCPakRatt (CSS) – PACKET/PACTOR
Digital Communications 17 Soundcard Technology
• Soundcards
– Internal to PC (built-in)
– External to PC (Tigertronics SL-USB, West Mountain Radio, US Robotics Navigator, MixW RigExpert, etc.)
Digital Communications 18 External Soundcard Devices Tigertronics, US Interface, West Mountain Radio, Buxcomm
Digital Communications 19 Soundcard Modes
• BPSK 31/63/125 • MFSK 8/16 • SSTV
• QPSK 10/31/50 • OLIVIA • MT-63 • MPSK • THROB • CHIP • PACKET • Domino • APRS • CCW • PAX • Contestia • PACTOR 1 • ALE • HF FAX • AMTOR FEC • COQUELET • WINMOR • RTTY • Hellschreiber
Digital Communications 20 Soundcard Software • Airmail • MT63 • SlowFeld
• DIGIPAN • MultiPSK • Stream • DigTRX • NBEMS • Throb • DM-780 (HRD) • NBF • TrueTTY • Feld Hell • PacLink • WinDRM • FLDIGI • Paxon • WinPack • FTV • PcPakRatt • WinPSKse • Hamscope • RDFT • WinWarbler • JVComm32 • RMS Express • WSJT • MixW • Sally • XPWin
• MMSSTV/RTTY • SCAMPDigital Communications 21
HRD - DM 780
Digital Communications 22 MixW
Digital Communications 23 MultiPSK
Digital Communications 24 FLDIGI
Digital Communications 25 DIGIPAN
CCARES/RACES Digital Communications 26 Paxon
CCARES/RACES Digital Communications 27 WinWarbler
CCARES/RACES Digital Communications 28 Accuracy
• Broadcast Mode – Character loss is not important
• Error Checking modes – FEC (Forward Error Correction) – ARQ (Automatic Repeat-reQuest)
Digital Communications 29 Accuracy
• The FEC mode is used where absolute accuracy is not paramount but a higher degree of message exchange reliability is. – A redundant data transmission technique that transmits the information using a predetermined algorithm (no handshaking)
Digital Communications 30 Accuracy
• The ARQ mode is used where absolute accuracy is paramount on the exchanged message. – It uses a handshaking technique to ensure absolute accuracy in the exchange of data. – When a block of the message is not received with 100% accuracy, the receiving station requests the entire block to be resent.
Digital Communications 31 “Waterfall” Displays
AMTOR
CW
FAX
HELLSCREIBER
Digital Communications 32 “Waterfall” Displays (cont)
FSK31
MT-63 (1000HZ)
PACTOR 1 PACTOR 2 PACTOR 3
PSK 31/63/125
Digital Communications 33 “Waterfall” Displays (cont)
SSTV
THROB
VHF PACKET
Digital Communications 34 Making the connection “without wires”
Receive = Radio Speaker - into - Computer Microphone Transmit = Radio Microphone – into – Computer Speaker
Digital Communications 35 Making the connection with wires
Digital Communications 36 Soundcard Interface - Improved • Two issues
1. TX & RX Audio isolation
2. PTT control
Note: Buxcomm Product Shown Digital Communications 37 Digital Messaging Schemes 1. Keyboard-to-Keyboard (Peer-to-Peer) - Typed message on keyboard 2. Station-to-Station (Peer-to-Peer) – Typed or text file message to screen – Typed or text file message to personal mailboxes (MBX) 3. Local Message Boards (BBS) – Central mailbox location for messages 4. Wide Area Systems – Winlink 2000 Global Radio eMail System
Digital Communications 38 PACKET
Digital Communications 39 PACKET System Options
Digipeater BBS
Station “D”
Station “B”
Station “C” Station “A”
Digital Communications 40 MS HyperTerminal & WinPack
Digital Communications 41 OutpostPM
Digital Communications 42 Create by Bob Bruninga, WB4APR
• Amateur PACKET Reporting System – “Maps and Messaging” – Over 40,000 users – Most common use is position reporting – Weather – Telemetry – 144.39 MHz
Digital Communications 43 Winlink 2000
Digital Communications 44 Is Winlink a system or software?
• Winlink is the system – We operate in the Winlink system • Airmail, RMS Express is the software to access the system – We install the software to do so.
Digital Communications 45 Winlink 2000 System
5 Fully redundant, mirrored, and worldwide dispersed Common Message Servers (CMS)
RMS ‘Gateways’
• Radio Message Servers “RMS” gateways are always connected to the CMS System via the Internet in a star network topology, serving as radio interface nodes on the Winlink 2000 network. – RMS Pactor for HF provides short or long haul availability to Internet e-mail. – RMS Packet for VHF/UHF “last mile” e-mail availability to Internet e-mail. – RMS Relay provides continual communications with the CMS system when no Internet is available to bridge the “last mile.” 46
Winlink Amateur Radio System
• 5 Common Message Servers (CMS) – San Diego – Perth, Australia – Wien (Vienna), Austria – Halifax, Nova Scotia Canada – Brentwood, TN
• 133 HF RMS Stations (FCC Ham channels) – PACTOR, WINMOR, Tri-Mode, BPQ32
• 473 UHF or VHF RMS stations – AX.25 PACKET protocol 47 Digital Communications
Winlink Gov’t/MARS System
• 5 Common Message Servers (CMS) (<< Same servers for Ham side) – San Diego, CA – Perth, Australia – Wien (Vienna), Austria – Halifax, Nova Scotia Canada – Brentwood, TN
• 65 HF RMS Stations (75 NTIA Channels) – PACTOR (46), WINMOR (19) , Tri-Mode, BPQ32
• 23 VHF RMS stations – AX.25 PACKET protocol
48 Digital Communications Winlink 2000 Access Modes
• TELNET (directly into your ISP/Internet connection)
• PACKET VHF or UHF RMS
• WINMOR HF RMS
• PACTOR I, II, III, IV HF RMS
• Tri-Mode RMS
• BPQ-32 RMS
Digital Communications 49 Winlink 2000 Topology Radio Message (aka “Gateway”) Server (HF/VHF/UHF) TELNET
The Internet “Cloud” Common USER TELNET TELNET essage M AIRMAIL Server (4) RMS Express PACLINK
Connected to Client PC or Network!
Digital Communications 50 Winlink Users • Approximately 14, 000 ham client accounts • Approximately 2,000 MARS client accounts • Approximately 10,000 Weekly Radio users communicating with over 98,000 Email recipients, • An average of 150,000 messages or 280,000 minutes monthly • An average duration of 3.4 Minutes at 3,600 bytes/per message. • The average time from message origination to pickup for delivery is approximately 1.0 minute, regardless of distance. • The greatest growth is now in Emergency Communications preparedness.
51 Digital Communications Winlink Station
Digital Communications 52 RMS Station (HF MARS Winmor & VHF MARS & UHF HAM PACKET)
CCARES/RACES Digital Communications 53 Airmail
Digital Communications 54 RMS Express & Paclink
Digital Communications 55 Digital Addressing (Hierarchical)
• PACKET (BBS) k7gjt • PACKET (Hierarchical) [email protected] • Winlink (standard internet SMTP) [email protected]
Digital Communications 56 HSMM-Mesh
Digital Communications 57 The Topology
Digital Communications 58 How does it work? • An HSMM-MESH node provides an endpoint connection AND a repeater • If one endpoint cannot see its desired destination, but CAN see nodes in between, the data will hop from one to the next until the final connection is made…. completely automatically • If one repeating node falls out, the software automatically re-routes traffic through other available nodes
Digital Communications 59 The Hardware • Router: LinkSys WRT-54G Series – 12VDC @ <1A – Uses “RP-TNC” antenna connector • Antenna Options Below – Typically Use ‘RP-SMA’ and ‘N’ connectors • Bi-directional amplifiers available
Verticals 8 Dbi 12 Dbi 15 Dbi 12 El beam = 20Dbi Circular, Rectangular or Flat Panel = 8-24Dbi 16 El beam = 24DBi Digital Communications 60 What can we do with it?
• Connect two or more devices… - Computers (s) - Webcam(s) - VoIP phone(s) - Server(s) - Anything that ‘talks’ TCP/IP over a computer network
• NOTE: An internet connection to one node provides the entire HSMM-Mesh network with internet access (FCC Part 15/Part 97 issue)
Digital Communications 61 A Typical Portable Omni- directional Node
Digital Communications 62 A Typical Portable Uni- directional Node
Digital Communications@ South Austin Medical Center 63 Digital Communications 64 Questions? [email protected]
Digital Communications Yep, that’s me!65