jcg gmdss symposium 2013 navdat : navigational data · jcg gmdss symposium 2013 navdat :...

NAVDAT Presentation /35

JCG GMDSS Symposium 2013

NAVDAT : Navigational Data

- System Presentation -

Pascal OLIVIER


From analog to digital in maritime

radio communications

The current analog radio modulation used in the Maritime radio communications:

Reduce the usable flow

Example: 50 bds for TELEX or NAVTEX

In this situation the size of transmit files and transmission duration are limited


New needs for the ships at sea

More frequent information

Increase in flow of information

Confidentiality of some information

Future evolution for e-Navigation


The digital modulation

Digital Modulation allows more important flow

15 to 25 kbit/s in a 10 kHz channel (more than 300 times the NAVTEX transmission)

Faster transmission time per message

...010101010101110...

Text Multimedia

Transmissions files not limited to the texts but also:

Drawings

Graphs

Pictures

Data…


Usable radio maritime bands (1)

We are looking for a large radio coverage with low cost of investment

MF Band

250kHz 2550kHz 490kHzNAVTEX

518kHzNAVTEX

500kHz

In the MF band (like NAVTEX 490 / 518 kHz)


Usable radio maritime bands (2)

Choice of the MF Band

This band procure a stable propagation on surface wave

Good radio coverage of 250/350 NM by coast station


The 500 kHz frequency: history (1)

Old frequency for distress and security in telegraphy

Telegraphy is Suppressed in 1997

Frequency 500 kHz not used since



The TITANIC

100 years ago (April 14th, 1912 at 23:40)

The TITANIC sent its SOS on 500 kHz in telegraphy mode

The TITANIC sank on April 15th, 1912 at 2:20



… 100 years afterwards

On the French initiative:

The World Radio Conference 2012 approved the worldwide exclusive usage of the frequency band 490 - 505 kHz for the maritime mobile service.

“ 100 years after the shipwreck of the TITANIC, the 500 kHz is returned to the sailors”


From the 500 kHz to the NAVDAT (1)

The French company KENTA prepared a first document presented to the Working group 5b at ITU on November 2009. This document described a digital system usable in the 500 kHz band

Evolution of this document with participation of USA, Denmark and Japan in May and November 2010

Presentation by KENTA of the technical annex in November 2010 describing the test results at sea carrier out on the car ferry PONT AVEN from Brittany ferries.


From the 500 kHz to the NAVDAT (2)

KENTA proposes the free name of NAVDAT for the system

In November 2011 the ITU-R Study Group 5 adopted the recommendation ITU-R-M [500 kHz] which will be published by March 2012

“ Characteristics of a digital system, named Navigational Data for broadcasting maritime safety and security related information from shore to ship in the 500 kHz band”


NAVDAT: General principle

Broadcast of digital files from coasts to ships

Sequential transmission : like NAVTEX (Also possible on Single Frequency Network SFN )

Broadcast modes:

General for all ships

Selective:

By geographical area

By group of ships

For a specific ship

Possibility of encryption for confidential information


NAVDAT: System architecture

The global architecture of the NAVDAT is similar as the NAVTEX

This reduce cost and facilitate the evolution from the NAVTEX to the NAVDAT


NAVDAT: Synoptic


Information sources

Same as the current NAVTEX system

Extended to other services

Very open on the future


Coastal infrastructure of the NAVDAT

Transmitting antenna with matching unit

500kHz Tx antenna

Digital Tx – KENTA500 kHz digital transmitter connected to a shore

network

Monitoring Receiver – KENTA

Monitoring receiver


Technical constraints for coast stations

Linearity of the RF transmitter for obtain a good Bit Error rate

Respect of the spectrum occupancy

Band-width of the antenna (higher than 10 kHz)

Efficiency of the antenna


NAVDAT on the ship

It’s a low cost system

Reception antenna like active antenna for electric or magnetic RF field

Automatic receiver being able to detect the type of modulations, the level of error corrections as well the broadcast mode

Interface to the user: dedicated display or internal network

NAVDAT

Receiver

RxAntenna

DedicatedDisplay

ShipLAN

GNSSShip Position


NAVDAT advantages

The introduction of the digital modulation into a 1 0 kHz band authorizes:

Flow rate about 15/ 25 kbit/s (according to the level of error correction used)

Possibility to transmit any type of files:

Text, Graphs, Pictures, data etc.

Automatic reception

Very open to the future needs without modifications


NAVDAT functionalities (1)

Given as example:

Type of messages: PRIORITY

Navigational warning



Given as example:


Navigational warningMeteorological warning



Given as example:



Meteorological warning

Search and rescue

Given as example:






Given as example:




Piracy warning

Given as example:




Search and rescue



Given as example:




Search and rescue

Piracy warning

Ices warning

For a specific ship (use of the MMSI)



Given as example:

Types of messages: INFORMATION OF NAVIGATION

Meteorological forecast



Given as example:



Local meteorological information

Pilot information

Tides and Current information



Given as example:



Local meteorological information

Pilot information

Tides and Current information

VTS traffic

Aids to navigation status

AIS report

Cartography of ices and icebergs



Given as example:

Types of messages: MESSAGES

Generals

For a geographical zone

For a group of ships

For a specific ship (use of the MMSI)

NAVDAT Presentation /35Page 29/25


Given as example:

Types of messages: WIDE SERVICES

Update of cartography



Given as example:



Graph of the traffic evolution on zone

Graph of weather evolution



Given as example:



Graph of the traffic evolution on zone

Graph of weather evolution

Information to fisherman

Harbor messages


Reception on the ship

The receiver is always on watch mode

It detects any digital reception in the band 495/505 kHz

It can automatically decode the received message withmodulation of 16 or 64 QAM (Quadrature Amplitude Modulation) and sequential or SFN mode

All priority received messages wait for operator validation


Management of received messages

When an encrypted message is received it’s necessary to use a key for decoding

This management calls upon traditional computer tools with:

Validation of received messages

Print of message if required

Transfer to specific service on board

Records of the files …


The NAVDAT system :

Use a radio band allocated by ITU ( International Telecommunication Union ) for a MARITIME EXCLUSIVE usage on a WORLDWIDE basis

Can re-use the current infrastructure NAVTEX for the information sources

Simple and safety coastal network

System very open on the next future

Conclusion


Questions and answers

Pascal OLIVIER KENTACEO

Tel: +33 298 521 602Email : [email protected]

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