challenges of data over hf radio · automatic message exchange –stanag 5066 4. link quality...
TRANSCRIPT
![Page 1: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/1.jpg)
Challenges of Data Over HF Radio
Presented to
The Radio Club of America
Technical Symposium
By Alan Spindel
Senior Electrical Engineer
HAL Communications
Champaign, IL
![Page 2: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/2.jpg)
The Many Challenges of HF Data
● Nature is against you
● Your fellow man is against you
● The planet is not your friend
● Everything else is against you
U.S. Department of the Interior/Hallie Larsen, National Park Service/Facebook
![Page 3: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/3.jpg)
Nature is Against You
● Limited bandwidth channel (~3KHz)
● Shannon's Law
– The maximum attainable error-free data speed, in bits per second (bps), is a function of the signal-to-noise ratio and bandwidth.
● Ionospheric radio is challenging
– Sun spots, fades, dropouts, selective fading
– Lightning, solar cycles
– Impulsive noise
• Fluctuating signal to noise ratio (SNR)
https://www.space.com/28857-aurora-photos-northern-lights-2015.html
![Page 4: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/4.jpg)
Your Fellow Man is Against You
Tom and Jerry are a trademark of Metro-Goldwyn-Meyer
![Page 5: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/5.jpg)
Your Fellow Man is Against You
● Welders, electric fences, chargers
● DC-DC converters, dimmers, and drives
● Plasma TVs, AC power distribution
● Broadband over Power Line (BPL)
● Broadcasters
● High-power military and sovereign stations
● Electro-Magnetic Pulse (EMP)
![Page 6: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/6.jpg)
The Planet is Not Your Friend
● Propagation Modes
● Ground wave
● Near Vertical Incident Skywave (NVIS)
● E-Layer skip skywave
● Back-scatter
● All combine to create multi-path distortion
● Earth’s own magnetic field flux has a value around 500 milligauss
![Page 7: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/7.jpg)
Everything Else is Against You
![Page 8: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/8.jpg)
Everything Else is Against You
● Component tolerances
● Natural laws of filter design
● Processor power
● International regulation
● Peak-average ratio of radios
● Narrow-band interference
● Inter-symbol interference
![Page 9: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/9.jpg)
Modem Design Theory
Courtesy HALComm
![Page 10: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/10.jpg)
Communication Channels
Modulator Channel Demodulator
Noise
![Page 11: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/11.jpg)
Modulation Schemes
● OOK -- On-Off Keying (CW)
● ASK -- Amplitude Shift Keying
● FSK – Frequency Shift Keying
● PSK – Phase Shift Keying
● QPSK – Quadrature Phase Shift Keying
● OFDM – Orthogonal FDM
● Serial-Tone
● QAM – Quadrature Amplitude Modulation
![Page 12: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/12.jpg)
HF Data Packet Format
Synchronization Preamble Payload + Redundancy Postamble
![Page 13: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/13.jpg)
Data Modem Accessories
● Coding and interleaving
● Bit scrambling
● Adaptive equalization
● Echo canceling
● AFC – Automatic frequency control
● ALC, AGC – Automatic level and gain control
● ARQ – Automatic Repeat reQuest
● Encryption
![Page 14: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/14.jpg)
Data Rates
• Data Rates
Data signaling rate (bps) = t k x modulation rate (Bd)
Where k = log2M is the number of binary digits per modulation symbol,
M is the number of modulation symbols,
and t is the number of tones.
• Throughput
Throughput rate (bps) = Data rate / (Beta + Tp)
Where Beta = coding (redundancy) overhead and
Tp is the channel probe and preamble overhead .
![Page 15: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/15.jpg)
Coding Conundrum
• More Data Reliability
• More coding redundancy
• Less data throughput
• Longer interleave
• Less Data Reliability
• Less coding redundancy
• More data throughput
• Shorter interleave
![Page 16: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/16.jpg)
Automatic Repeat reQuest (ARQ)
https://image.slidesharecdn.com/ch-11-090721210444-phpapp02/95/ch-11-7-728.jpg?cb=1248210318
![Page 17: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/17.jpg)
ARQ Conundrum
● Smaller Blocks (Stop-and-Wait ARQ)
– Less costly retry, low SNR
– Less throughput, high SNR
● Bigger blocks
– More costly retry, low SNR
– More throughput, high SNR
● Adaptive ARQ (Go-Back-N ARQ)
– More complex implementation
![Page 18: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/18.jpg)
HF Technology Generations
● Legacy
● Solid state technology
● First Generation
● Dedicated digital hardware
● Second Generation
● Current technology (FSK PSK)
● Automated encrypted voice talk groups
● Leverages TCP/IP networking
● Groupware applications – email and chat
● Third Generation
● Wider bandwidth, faster data
● More automated
● Faster call setup times
● Lower SNR (PSK + QAM)
● Multiple access
![Page 19: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/19.jpg)
2G HF Technology
Courtesy Barrett Radio
![Page 20: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/20.jpg)
2G Communications System
https://www.mathworks.com/help/comm/examples/defense-communications-us-mil-std-188-110b-baseband-end-to-end-link.html
![Page 21: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/21.jpg)
MIL-STD-188-141 Layers
1. Network coordination and management
2. Message store and forward
3. Automatic message exchange – STANAG 5066
4. Link Quality Analysis and channel selection
5. Connectivity exchange
6. Polling
7. Sounding - ALE
8. Scanning - SELCAL
9. Selective calling and handshake
10. Baseline system (plain vanilla radio)
![Page 22: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/22.jpg)
Automatic Link Establishment (ALE)
● Simplified user interface
● Familiar, telephone-type call experience
● ALE uses sounding for channel estimation
● Builds and maintains an almanac of propagation data
● Estimates the best frequency at call time
http://www.hflink.net
![Page 23: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/23.jpg)
Automatic Link Establishment (ALE)
Courtesy US Army MARS
![Page 24: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/24.jpg)
ALE Generations
● First Generation ALE – No longer used
● 2G ALE
– Widely deployed, expensive
– Can be bulky, complicated, slow call setup time
– FSK restricts ALE use in low SNR environments
● 3G ALE under early deployment
– Uses PSK
– Designed for tactical nets
– Shorter call setup time
– PSK works better in lower SNR applications
• Other Commercial Link Management Implementations
![Page 25: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/25.jpg)
HFLINK – HF Propagation Map
http://hflink.com/propagation/
![Page 26: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/26.jpg)
Automatic Link Maintenance
● ALM – Automatic Link Maintenance
– Nailed Up HF connections between stations
• 3G ALE – Connection Management (CM)
• Relink
• Link negotiation
• Coordinated departure to new channel
• Waveform/data rate negotiation
![Page 27: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/27.jpg)
Channel Sharing
● Holy Grail of HF Data - Channel Sharing
● Multiple Access Carrier – CSMA, CDMA
● Token passing schemes
● UWB schemes
● Correlated Hopping Spread Spectrum (CHESS)
● Time Slot Broadcast
![Page 28: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/28.jpg)
Software Defined Radio
Courtesy Barrett Radio
![Page 29: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/29.jpg)
Commercial Aviation / Marine
● HFDL – ACARS
● HF SELCAL
● SITOR-A for GMDSS and SOLAS
● SITOR-B is FEC broadcast for USCG SafetyNet
● DSC Automated voice/data is also part of GMDSS
● WEFAX Weather facsimile broadcasts
![Page 30: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/30.jpg)
Amateur Radio Digital Modes
● Classic TNC modes
– RTTY
– G-TOR
– PACTOR
– AMTOR
– CLOVER
![Page 31: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/31.jpg)
Amateur Radio Digital Modes
● PSK31 PSK63
● SSTV
● HF HD SSTV
● MFSK
● MT63
● Hell
● HF Packet
● THOR
● JT65
● JT6M
● THROB
● OLIVIA CONTESTIA
● DRM
● DOMINO
● PAX, PAX2
![Page 32: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/32.jpg)
Amateur Radio Digital Modes
● New, Exciting Amateur Modes
– WSPR - Sounding beacon
– 25 mW signal gives 450,000 Km/W
– WSJT - Weak signal
– ROS - Super low SNR work
– RSID - Auto ID for digimodes
–Reed-Soloman IDentifier
– VIDEO ID - Latest Gadget
http://blog.g4ilo.com/2010/03/show-your-id.html
![Page 33: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/33.jpg)
Military Standard Waveforms
● QAM rediscovered for HF data
● Serial tone PSK waveforms
● MIL-STD-188-110B
● STANAG 4539
● ARQ schemes / network layer stacks
● FED-STD-1052
● STANAG 5066
● MIL-STD-188-141
![Page 34: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/34.jpg)
Military Standard Waveforms
From “Third-Generation and Wideband HF Radio Communications”, Johnson, et al.
![Page 35: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/35.jpg)
3G Military Waveforms
● MIL-STD-188-110D
● Up to 24KHz
● Wideband
● Worldwide HF video, command and control
● Burst waveforms
● Highly adaptive communication systems
![Page 36: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/36.jpg)
Emergency Communications
● SHARES
● MARS
● ARRL ARES
● RACES
● Winlink
● fldigi MT63 HF / VHF
● ARRL NTS
● Red Cross
● SATERN
● SouthBEARS
● LDS
● INTERCON
● MMSN
![Page 37: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/37.jpg)
EasyPal SSTV EmComm Reporting
Courtesy commacademy.org
![Page 38: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/38.jpg)
Challenges of Data Over HF Radio
Presented to
The Radio Club of America
Technical Symposium
By Alan Spindel
Senior Electrical Engineer
HAL Communications
Champaign, IL
![Page 39: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/39.jpg)
Glossary2G - 2nd Generation technology era as in “2G ALE”.3G - 3rd Generation technology.AFC - Automatic Frequency Control, see ALC.ALC - Automatic Level Control, a less aggressive form of AGC.ALE - Automatic Link EstablishmentALM - Automatic Link MaintenanceARQ - Automatic Repeat reQuestASK - Amplitude Shift KeyingBaud - The actual physical symbol rate in symbols per secondBPL - Broadband Over Power LinesBPS - Bits Per SecondBPSK - Binary PSKCDMA - Code Division Multiple Access, a channel sharing scheme, see CSMA.CM - Connection Management, a feature of 3G ALE.CSMA - Carrier Sense Multiple Access, see CDMACW - Continuous Wave, a synonym for Morse code transmission.EMP - Electromagnetic Pulse; Satan’s workshop.FIPS - Federal Information Processing Standards
![Page 40: Challenges of Data Over HF Radio · Automatic message exchange –STANAG 5066 4. Link Quality Analysis and channel selection 5. Connectivity exchange 6. Polling 7. Sounding - ALE](https://reader034.vdocuments.mx/reader034/viewer/2022042207/5eaa360dea48c7512c76a54f/html5/thumbnails/40.jpg)
GlossaryFSK - Frequency Shift Keying, arguably the most popular data modulation technique.HF - High Frequency (Radio), usually agreed on as 3-30 MHz radio operation.ISI - Inter-Symbol Interference, primary cause of data loss in HF data transmission.Legacy - A technological era of less practical application to modern applications. MIL-STD - Prefix to a specification document from the US military.NVIS - Near Vertical Incident Skywave, a HF radio propagation mode.OFDM - Orthogonal Frequency Division MultiplexingOOK - On Off Keying, the simplest form of data modulation.PSK - Phase Shift Keying, a very popular and effective modulation scheme.QAM - Quadrature Amplitude ModulationQPSK - Quadrature Phase Shift KeyingSELCAL - Selective Calling, an annunciator scheme, also an ITU standard for aviation radio.SELCALL - A synonym for SELCAL, both are pronounced “sell-call”.SNR - Signal to Noise Ratio, high is good, low is bad. STANAG - STANdards Agreement, a specification document for a NATO standard.UWB - Ultra-WideBand, a very wide spread spectrum modulation scheme.