View
214
Download
0
Category
Tags:
Preview:
Citation preview
New HF/MF Digital Maritime Mobile
Systems
Globe WirelessGlobe Wireless
Global provider of Maritime Communications Solutions
Managing customer email & data services for 15 years
Installed on more than 4000 ships Basis of meeting regulatory driven
applications– GlobeAlert ship security alert system
– GlobeLocator long range identification and tracking of ships
– GlobeWeather forecasts
– Other fleet management functions
Efficient large file transfer Marinet communications
protocols Sustained high speed transfer Full duplex communications Store and forward delivery
Least Cost Routing Email connectivity Data Connectivity GlobeCrewTM Kiosk
Satellite
CUSTOMER VESSEL
CUSTOMER OFFICE
HF Radio
Maritime DataNetwork
Cost Effective Messaging Near Real-Time Delivery Timely delivery
confirmation Notification of satellite
traffic waiting on shore
Network Operations Center
The Secure Message Handling System automatically routes all incoming and outgoing messages to destinations
INTERNET
INTERNET
Email Fax Telex Cable Telephone
Use existing office equipment and systems to exchange messages and data with
vessels at sea
Service Overview
GlobeSecureSM
Optional Virtual Private Network
with Globe Wireless
CrewEmail
ApplicationData
Satellite Delivery
Connected Worldwide
The Maritime Data Network
“Always on” connection 25 HF stations world wide Approximately 300 channel pairs Half receive and half transmit Delivers 50,000 messages per day Alternative to satellite systems Traffic doubles every 18 months
– Message growth and new applications– Flexible for efficiency improvement
Globe Wireless ReliabilityGlobe Wireless Reliability
Guaranteed message delivery Multiple frequencies and stations Network operating centers in California and England All stations have backup power 99.97% service availability over the last four years Ships use both HF and satellite communications Shipboard equipment is self diagnosing 24/7 customer support
Below Deck Equipment
Personal computer Marine HF radio Globe Wireless modem Power supply
Above Deck Equipment
Vertical antenna Antenna coupler GPS receiver
Globe Wireless Modem
Small form factor Uses digital signal processing technology Call set up protocol is a simple extension to
NBDP Bandwidth efficiency of about two BPS per
Hertz OFDM modulation rather than single carrier
– Resistant to multipath fading
NBDP Globe Wireless
500 Hz, 1 Tone
3000 Hz, 32 Tones
OFDM Spectrum
0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000
-50
-45
-40
-35
-30
-25
-20
-15
-10
-5
02.8 kHz Wideband Signal Spectrum
Frequency (Hz)
Magnitude(dB)
OFDM Parameters Carrier
– 300 HF frequency pairs in the marine bands– 32 tones– QPSK modulation– 62.5 Hz carrier spacing– 2 ms guard interval– 700-2700 Hz occupied bandwidth
Timing– 1.520 seconds per burst cycle– 1.095 second burst duration (tone + sync + data)– 0.425 second response (ACK/NACK + round trip delay +
processing time)
Data efficiency– 2 bits/second/Hz
Vessel Performance Example
Vessel: Island Time Total bytes-shore to ship 12986 Successful links OFDM 8PSK 4PSK 200FSK 100FSKDate: 02/21 Total bytes-ship to shore 5116 Link mode % time 8.7 0.0 86.7 4.6 0.0GCC: GCC 4.13 Total messages 44(4) Ave bytes/min 293 230 129 COD 0.90Modem: GL 5100 Average message size 445 Link mode % bytes 11.0 0.0 86.0 3.0 0.0
Ave data rate (bytes/min) 251(233:439) CC-sig lvl:tones 0.47 Tones 19Ave link start time (min) 1.4 CC-sig lvl:link time -0.16Average link time (min) 1.9(2:1.7) CC-sig lvl:bytes/min 0.23Link success rate(%) 89(88:100) CC-bytes/min:msg size 0.54
WCC(26:Louisiana) 12.6245(3) 13.0275(7) 17.3754(12)WNU(8:Louisiana) 8.4255(1) 12.6704W(4) 12.9665(6) 16.942(10)8PO(7:Barbados) 12.6804(5) 16.8415(9) 17.1554(11) 19.7414(14)VCT(2:Newfoundland) 8.6614(2) 13.1624(8)KPH(1:California) 19.7305W(13)
Frequency vs TOD
0
5
10
15
20
25
0 5 10 15 20
Hour of Day
MH
z
Successful Links Failed Links
Link Time Performance
0
5
10
15
20
25
2.5 5
7.5 10
12.5 15
17.5 20
22.5 25
27.5 30
Mor
e
Minutes
No
. o
f L
inks
0.00%20.00%40.00%60.00%80.00%100.00%120.00%
Successful Links Failed Links Cumulative %
Link Data Rate
0
5
10
15
20
25
100
200
300
400
500
600
700
800
90010
00M
ore
Bytes per Minute
Nu
mb
er
of
Lin
ks
020040060080010001200
Byt
es
Number of Links Message Size
Shore Station Performance
WCC
WNU
8PO
VCT
KPH
WCC WNU 8PO VCT KPH
WCCWNU 8PO
VCT
KPH
0
50
100
150
200
250
300
350
0 1 2 3 4 5 6
Link Time (secs) Signal Strength Data Rate
Frequency Use
0
5
10
15
20
25
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Number of Frequencies
Frequencies (MHz) Number of Attempts
Link Performance
0
100
200
300
400
500
600
700
1 2 3 4 5 6 7 8 9 10 11 12 13 14
Number of Frequencies
Link Time (secs) Signal Strength Data Rate
Adaptive HF Features
Dynamic data rate adjustment Automatic link establishment Adaptive frame mapping Individual tone retransmission Least cost routing Frequency agility
Planned New Features
Next generation protocol– Capacity improvement– Adds broadcast/multicast capability– Message delivery in as little as 2 seconds
Similar to current protocol– Same OFDM modulation and spectral efficiency– Improved timing and protocols
Protocol Improvements
New protocol is twice as efficient as current protocol New protocol eliminates call set up time No hardware changes on ship Twice as many vessels plus broadcasts, paging, network
messages on the same number of channels
Current Protocol
Ack
Data
Ack
Data
Ack
Data
Ack
Data
Data Data Data Data
Data Data Data Data
New Protocol
Summary
The Globe Wireless Maritime Data Network is operational world wide
Being used by 4000+ vessels Offers greater flexibility than satellite only
systems Ongoing improvements for more capacity
and new services Increased spectral efficiency and more HF
channels are both needed for continued growth in maritime use
Recommended