Globe Wireless HF Network

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Globe Wireless HFHigh Frequency (3-30 MHz) Network
GW.jpg
Frequencies 3 MHzMegaHertz (MHz) 10^6 Hz3,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
3,000 kHzKiloHertz (kHz) 10^3 Hz
,30 MHzMegaHertz (MHz) 10^6 Hz30,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
30,000 kHzKiloHertz (kHz) 10^3 Hz
3,000 kHzKiloHertz (kHz) 10^3 Hz
MHzMegaHertz (MHz) 10^6 Hz
30,000 kHzKiloHertz (kHz) 10^3 Hz
30 MHzMegaHertz (MHz) 10^6 Hz
Frequency Range MHzMegaHertz (MHz) 10^6 Hz3,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
3,000 kHzKiloHertz (kHz) 10^3 Hz
- 30 MHzMegaHertz (MHz) 10^6 Hz30,000,000 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).
30,000 kHzKiloHertz (kHz) 10^3 Hz
Mode USBUpper Side Band Modulation (Radio, referring to reception and modulation mode)Universal Serial Bus (Computer, referring to USB Ports and cables)
Modulation PSKPhase-Shift Keying,FSKFrequency-Shift Keying,OFDMOrthogonal Frequency-Division Multiplexing
ACFAutoCorrelation Function
Bandwidth 400 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz).0.4 kHzKiloHertz (kHz) 10^3 Hz
4.0e-4 MHzMegaHertz (MHz) 10^6 Hz
,750Hz0.75 kHzKiloHertz (kHz) 10^3 Hz
7.5e-4 MHzMegaHertz (MHz) 10^6 Hz
,2000HzkHzKiloHertz (kHz) 10^3 Hz
0.002 MHzMegaHertz (MHz) 10^6 Hz
0.4 kHzKiloHertz (kHz) 10^3 Hz
4.0e-4 MHzMegaHertz (MHz) 10^6 Hz
kHzKiloHertz (kHz) 10^3 Hz
0.002 MHzMegaHertz (MHz) 10^6 Hz
Location Worldwide
Short Description Globe Wireless' Maritime Digital Radio was a system of 24 stations around the globe offering data services to large cargo vessels. Since 2014, GW has discontinued their HFHigh Frequency (3-30 MHz) network.
I/Q Raw Recording
Audio Sample
Globe Wireless's HFHigh Frequency (3-30 MHz) Network was a system of 24 stations around the globe offering data services to large cargo vessels. Since 2014, GW has discontinued their HFHigh Frequency (3-30 MHz) network, and the company has been purchased by Inmarsat, which is focusing primarily on satellite networks. Globe Wireless was a provider of HFHigh Frequency (3-30 MHz) and satellite email and data services to the shipping industry.

The remnants of the Globe Wireless network is scattered all over the world. Parts of the HFHigh Frequency (3-30 MHz) network are now used by Swisscom, including its own Bern Radio in Switzerland. [1] [2] Swisscom solely uses PACTOR III with huffman compression for data transfer. [3]

Modes[edit]

There are a number of modes that were used with Globe Wireless, including their own proprietary ODFM DQPSKDifferential Quadrature Phase-Shift Keying modes used for data transmission.

  • GW-FSKFrequency-Shift Keying:
    • GW-FSKFrequency-Shift Keying is Globe Wireless's "Idle Channel" or "Free Signal" marker. It is continuously broadcasted from shore stations out to sea, and ships use them to know which channel has the best signal quality if they want to establish a connection. Has a bandwidth of 400Hz and operates as Simplex ARQAutomatic Repeat reQuestAutomatic Repeat Query.
  • GW-PSKPhase-Shift Keying:
    • GW-PSKPhase-Shift Keying is also used in place of FSKFrequency-Shift Keying depending on the propagation situation. Also operated with 400Hz bandwidth and Simplex ARQAutomatic Repeat reQuestAutomatic Repeat Query.
  • GW-OFDMOrthogonal Frequency-Division Multiplexing (Orthogonal Frequency-Division Multiplexing):
    • GW-OFDMOrthogonal Frequency-Division Multiplexing is the main data mode for Globe Wireless. GW-OFDMOrthogonal Frequency-Division Multiplexing uses DQPSKDifferential Quadrature Phase-Shift Keying with OFDMOrthogonal Frequency-Division Multiplexing modulation and features adaptive speed with modes from 12 to 32 sub-carriers with 62.5Hz sub-carrier spacing. They are chosen dynamically based on the noise level and propagation ability. The bandwidth range for OFDMOrthogonal Frequency-Division Multiplexing is from 700-2700 HzHertz (Hz), unit of frequency, defined as one cycle per second (1 Hz)..
  • GW-CLOVER-400 with SITOR:
    • Before GW-OFDMOrthogonal Frequency-Division Multiplexing and the FSKFrequency-Shift Keying/PSKPhase-Shift Keying modes, Globe Wireless used SITOR as the "Idle Channel", as SITOR was more ubiquitous at the time among the maritime industry. To transmit data, Globe Wireless partnered with HAL Communications to develop a special proprietary mode, CLOVER-400, that could be used for shore to ship communications. It was a special variant of CLOVER that only occupied 400Hz of bandwidth, which met FCC requirements (FCC Part 80.211 (f) Limits). The shore stations would transmit first in SITOR. If they were able to identify a ship that was CLOVER-400 compatible, they would switch to CLOVER to transmit the data.

Mode Samples[edit]

Globe Wireless OFDMOrthogonal Frequency-Division Multiplexing DQPSKDifferential Quadrature Phase-Shift Keying
12-Carrier

12-Carrier.jpg
14-Carrier

14-Carrier.jpg
16-Carrier

16-Carrier.jpg
18-Carrier

18-Carrier.jpg
20-Carrier

20-Carrier.jpg
22-Carrier

22-Carrier.jpg
24-Carrier

24-Carrier.jpg
26-Carrier

26-Carrier.jpg
28-Carrier

28-Carrier.jpg
30-Carrier

30-Carrier.jpg

Globe Wireless "Free Signals"

FSKFrequency-Shift Keying Marker PSKPhase-Shift Keying Marker


GW-FSK.jpg


GW-PSK.png

Decoding Software[edit]

Hobby Level Software
  • Sorcerer
  • Rivet (100 baudBaud (unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second. FSKFrequency-Shift Keying only)
Professional Equipment/Software
  • Hoka Code 300-32
  • Wavecom W-Code
  • Wavecom W-Spectra

Video Examples[edit]

Additional Links[edit]

Additional Images[edit]