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1 INTRODUCTION

Technological progress in electronics, radio

communications and information technology results

in the constant emergence of new proposals for

modifications to the equipment and systems used on

sea-going vessels. The principles and scope of

equipment for these vessels, related to ensuring their

safety, are strictly regulated by the International

Maritime Organization (IMO), with merit-related

support by its committees and sub-committees. In

2006, several countries submitted a proposal to the

IMO Maritime Safety Committee (MSC) for preparing

a broad strategy for the inclusion of new technologies

in a comprehensive manner, to ensure their

compatibility with existing navigation and

communication technologies and services [1]. In

response to this proposal, the MSC took the decision

to initiate work on the “e-navigation” project through

two IMO technical sub-committees: Sub-Committee

on Safety of Navigation (NAV) and Sub-Committee

on Radiocommunications, Search and Rescue

(COMSAR). The project coordinator became the NAV

Sub-Committee [1]. The International Association of

Marine Aids to Navigation and Lighthouse

Authorities (IALA), International Hydrographic

Organisation (IHO) and International Federation of

Shipmasters' Associations (IFSMA) were also invited

to participate in the project. As a result of the

organisational changes in the IMO sub-committees in

2013 coordination over the e-navigation project was

entrusted to a new sub-committee formed by merging

the NAV and COMSAR sub-committees, i.e. Sub-

Committee on Safety of Navigation, Communication

and Search and Rescue (NCSR).

Doubtlessly, one of the key elements of e-

navigation will be a radio communication data

transmission network based on new systems and

those already used in maritime communications. The

above led the IMO to undertaking work in 2012 on

reviewing and modernising the Global Maritime

Distress and Safety System (GMDSS) used in

maritime radio communications. The first phase of

this project concerned a “High-Level Review”, where

fundamental elements of the GMDSS were analysed.

During phase two, in 2013–2016, a “Detailed Review”

of the GMDSS was performed. Another phase,

completed in 2017, concerned the preparation of a

“GMDSS Modernization Plan”. According to this

plan, all works carried out by the NCSR

subcommittee on the modernization of the system

Key Points of the Modernized GMDSS System

. Korcz

Gdynia Maritime University,

Gdynia, Poland

ABSTRACT: The article presents the reasons and the entire process of work on the modernization of the

GMDSS system. The main legal and technical aspects of the modernization of the GMDSS system were

discussed as well. New devices and systems of the modernized GMDSS system were described. On the basis of

the key points of the modernized GMDSS, an attempt was made to evaluate the entire project.

http://www.tr

ansnav.eu

the

International Journal

on Marine Navigation

and Safety of Sea Transpor

tation

Volume 17

Number 1

March 2023

DOI: 10.12716/1001.17.01.

140

were to be completed in 2021. So, the NCSR Sub-

Committee during 8 session has completed its review

of the Global Maritime Distress and Safety System

(GMDSS) requirements, agreeing draft amendments

to the International Convention for the Safety of Life

at Sea (SOLAS), 1974 and other existing instruments.

These amendments are intended to enable the use of

modern communication systems in the GMDSS whilst

removing requirements to carry obsolete ones.

Finally draft amendments to the SOLAS

Convention were presented at the 104th Session of the

Maritime Safety Committee (MSC), with a view to

approval and subsequent adoption into MSC 105 in

2022, so that they can enter into force on 1 January

2024.

The work on the GMDSS modernization project

can be broken down into tasks concerning the legal

and technical aspects related to implementation of

new maritime radio communication systems and

modification of existing ones [2].

The article presents the main results of work on the

GMDSS modernization project, carried out by the

NCSR Sub-committee, the IMO Correspondence

Group on the Review of the GMDSS and the Joint

IMO/ITU Experts Group, in which the author of the

article participated.

2 LEGAL ASPECTS OF THE GMDSS

MODERNIZATION

The legal aspects of the GMDSS modernization concern

mainly the regulations issued by the IMO and also issued by

the ITU (International Telecommunications Union).

2.1 IMO regulations

IMO legal aspects of the GMDSS modernization

mainly concern amendments to the Safety Of Life At

Sea (SOLAS) Convention and its related documents.

The SOLAS Convention defines uniform rules and

regulations for the minimum required equipment of

marine vessels, with section 4 devoted to the

radiocommunication.

As a result of the work on the modernization of

GMDSS, Search and Rescue Locating Devices -

SARLD regulations, i.e. SART (Search And Rescue

Transponder) and AIS-SART (Automatic

Identification System - Search and Rescue

Transmitter), have been transferred from Chapter III

(LIFE-SAVING APPLIANCES AND

ARRANGEMENTS) to Chapter IV

(RADIOCOMMUNICATIONS) of the SOLAS

Convention [3].

A very important change in the SOLAS

Convention concerns the definition of sea area A3.

After discussion, the following definition was

adopted [3]:

“Sea area A3 means an area, excluding sea areas A1 and

A2, within the coverage of a recognized mobile satellite

service supported by the ship earth station carried on board,

in which continuous alerting is available.”

In the above definition “recognized mobile satellite

service” means any service which operates through a

satellite system and is recognized by the IMO, for use

in GMDSS.

Another significant change in the SOLAS

Convention concerns the Functional requirements of

the ship's radio station. According to the changes

introduced to the Convention every ship, while at sea,

shall be capable of [3]:

1. performing the GMDSS functions, which are as

follows:

1. transmitting ship-to-shore distress alerts by at

least two separate and independent means,

each using a different radiocommunication

service;

2. receiving shore-to-ship distress alert relays;

3. transmitting and receiving ship-to-ship

distress alerts;

4. transmitting and receiving search and rescue

coordinating communications;

5. transmitting and receiving on-scene

communications;

6. transmitting and receiving signals for locating;

7. receiving MSI;

8. transmitting and receiving urgency and safety

communications; and

9. transmitting and receiving bridge-to-bridge

communications; and

2. transmitting and receiving general

radiocommunications.

In the above functional requirements [3]:

− Locating means the finding of ships, aircraft,

survival craft or persons in distress;

− Maritime Safety Information (MSI) means

navigational and meteorological warnings,

meteorological forecasts and other urgent safety-

related messages broadcast to ships;

− Bridge-to-bridge communications means safety

radiocommunications between ships from the

position from which the ships are normally

navigated;

− General radiocommunications means

communications other than distress, urgency and

safety communications.

It should be noted that the above functional

requirements clearly separate the functions related to

GMDSS (distress, urgency and safety

communications) from the functions related to general

communications. Definitions of sea areas A1 and A2

was left unchanged. Sea area A4 was not redefined,

but as it is the area outside sea areas A1, A2 and A3, it

will vary for ships using different mobile satellite

communication providers.

Taking into account the changes presented above,

the Ship requirements contained in Part C of Chapter

IV of the SOLAS Convention have been changed

accordingly.

All equipment to which the Chapter IV of the

SOLAS Convention applies shall be of a type

approved by the Administration. Such equipment

shall conform to appropriate performance standards

not inferior to those adopted by the IMO. The

resolutions adopted in the above scope by the IMO

have been collected in one Regulation (Regulation 14

– Performance standards) and ordered with regard to

[3]:

141

− General requirements,

− VHF equipment,

− MF and HF equipment,

− Ship earth stations and enhanced group call (EGC)

equipment,

− Integrated radiocommunication systems,

− Emergency position-indicating radio beacons, and

− Search and rescue transmitters and transponders.

In addition, as a result of work on the

modernization of GMDSS certain regulations of

Chapter IV were modified, as they were simply

outdated or incorrect.

Other major work has been done with regard to

documents relating to the SOLAS Convention.

Following a comprehensive review of the Global

Maritime Distress and Safety System (GMDSS) by the

Sub-Committee on Navigation, Communications and

Search and Rescue (NCSR), the MSC 104 in 2021

approved a set of associated amendments and

revisions to existing related instruments. The aim of

all amendments is to enable the use of modern

communication systems in the GMDSS whilst

removing requirements to carry obsolete systems.

It should be emphasized that the revision of the

relevant regulations in SOLAS chapters IV and

preparation of related and consequential amendments

to other existing instruments is the result of a decade

of detail-oriented work by IMO, in particular by the

NCSR Sub-Committee.

2.2 ITU regulations

As mentioned earlier the legal aspects of the GMDSS

modernization concern the regulations issued by the

ITU (International Telecommunications Union), as

well. These regulations mainly concern the provisions

of the Radio Regulations and the revision of the

relevant ITU Resolutions and Recommendations

adopted at the World Radiocommunication

Conferences (WRCs). Since the beginning of work on

the review and modernization of the GMDSS, two

World Radiocommunication Conferences have been

held i.e. in 2015 (WRC-15) and in 2019 (WRC-19).

During WRC-15, there was no agenda item directly

related to the modernization of the GMDSS system.

The only item on the agenda of this Conference was

item 1.16:

“1.16 to consider regulatory provisions and spectrum

allocations to enable possible new Automatic Identification

System (AIS) technology applications and possible new

applications to improve maritime radiocommunication in

accordance with Resolution 360 (WRC-12)”.

Resolution 360 (WRC-12) concerned:

Consideration of regulatory provisions and spectrum

allocations for enhanced Automatic Identification

System technology applications and for enhanced

maritime radiocommunication.

During the next World Radiocommunication

Conference in 2019 (WRC-19), two points were

directly related to the modernization of the GMDSS

system:

“1.8 to consider possible regulatory actions to support

Global Maritime Distress Safety Systems (GMDSS)

modernization and to support the introduction of additional

satellite systems into the GMDSS, in accordance with

Resolution 359 (Rev.WRC 15); and

1.9.2 modifications of the Radio Regulations, including new

spectrum allocations to the maritime mobile-satellite service

(Earth to space and space-to-Earth), preferably within the

frequency bands 156.0125-157.4375 MHz and 160.6125-

162.0375 MHz of Appendix 18, to enable a new VHF data

exchange system (VDES) satellite component, while

ensuring that this component will not degrade the current

terrestrial VDES components, applications specific

messages (ASM) and AIS operations and not impose any

additional constraints on existing services in these and

adjacent frequency bands as stated in recognizing d) and e)

of Resolution 360 (Rev.WRC 15) - Consideration of

regulatory provisions for updating and modernization of

the Global Maritime Distress and Safety System”.

Resolution 359 (Rev.WRC 15) concerned:

Consideration of regulatory provisions for updating

and modernization of the Global Maritime Distress

and Safety System, and Resolution 360 (Rev.WRC 15)

concerned: Consideration of regulatory provisions

and spectrum allocations to the maritime mobile-

satellite service to enable the satellite component of

the VHF Data Exchange System and enhanced

maritime radiocommunication.

The World Radiocommunication Conferences 2015

and 2019 revised Appendix 18 of the Radio

Regulations, the VHF maritime radio frequency band,

to designate frequency channels to be used for VDES

in accordance with the most recent version of

Recommendation ITU-R M.2092 - Technical

characteristics for a VHF data exchange system in the

VHF maritime mobile band. These VDES channels

were duplex channels with two bands separated by

4.6 MHz, where both bands are used to facilitate

VDES communications between ships, shore stations,

and satellites. Since 2024 all the VDES VHF channels

shall only be used for the VDES

(MSC.1/Circ.1460/Rev.2) globally (Fig. 1) [4].

Figure 1. International availability of VDES spectrum (as

App.18 of ITU Radio Regulations) [4]

In 2022 ITU has published latest version of ITU-R

M.2092-1 incorporating changes to add VDES Satellite

functionality and updates consequential to feasibility

tests [5].

It should be mentioned that the World Radio

Conference 2012 approved the worldwide exclusive

usage of the frequency band 495 - 505 kHz for the

maritime mobile service for the exclusive use of

NAVDAT. In 2011 the ITU-R Study Group 5 adopted

the Recommendation ITU-R-M.2010 which will be

142

published in 2012 “Characteristics of a digital system,

named Navigational Data for broadcasting maritime

safety and security related information” [6]. In 2014,

Recommendation ITU-R M.2058 “Characteristics of a

digital system, referred to as navigational data for

broadcasting maritime safety and security related

information from shore-to-ship in the maritime HF

frequency band” [7] was adopted. The adopted

frequency bands for NAVDAT HF are given in Table

1 (frequencies of RR Appendix 17).

Table 1. Frequencies for NAVDAT HF system [7]

________________________________________________

Central frequency (kHz) Limits (kHz)

________________________________________________

4 226 4 221 to 4 231

6 337.5 6 332.5 to 6 342.5

8 443 8 438 to 8 448

12 663.5 12 658.5 to 12 668.5

16 909.5 16 904.5 to 16 914.5

22 450.5 22 445.5 to 22 455.5

________________________________________________

Wherein, the main international NAVDAT HF

frequency is 4 226 kHz.

As a result of further work on NAVDAT, ITU

published Report ITU-R M.2443-0 "NAVDAT

Guidelines" in 2022, and updated versions of the

recommendations ITU-R-M.2010 and

Recommendation ITU-R M.2058 in 2023.

In addition to the above-mentioned main

regulations regarding the modernization of GMDSS,

ITU also introduced a number of changes to improve

or update the existing provisions.

2.3 Upcoming regulations

In order to complete the process of GMDSS

modernization, further work is being carried out by

the IMO and ITU. The expression of these works are

the following items on the agenda of the NCSR Sub-

Committee planned for discussion in 2023 during its

10 sessions:

1. Development of amendments to SOLAS chapters

IV and V and performance standards and

guidelines to introduce VHF data exchange system

(VDES),

2. Development of performance standards for a

digital navigational data system (NAVDAT),

3. Developments in GMDSS services, including

guidelines on maritime safety information (MSI),

4. Revision of the Criteria for the provision of mobile

satellite communication services in the Global

Maritime Distress and Safety System (GMDSS)

(resolution A.1001(25)), and

5. Response to matters related to the ITU-R Study

Groups and ITU World Radiocommunication

Conference.

The upcoming World Radiocommunication

Conference (WRC-23), which will take place from 20

November to 15 December 2023, will deal with the

following agenda item directly related to the

modernization of the GMDSS too:

“1.11 to consider possible regulatory actions to support the

modernization of the Global Maritime Distress and Safety

System and the implementation of e-navigation, in

accordance with Resolution 361 (Rev.WRC-19)”.

In accordance with Resolution 361 (Rev.WRC 19),

this agenda item consists of three different issues

which should be treated separately:

1. to consider possible regulatory actions, based on

the ITU Radiocommunication Sector (ITU R)

studies, taking into consideration the activities of

IMO, as well as information and requirements

provided by IMO, to support GMDSS

modernization;

2. to consider possible regulatory actions, including

spectrum allocations based on the ITU

Radiocommunication Sector (ITU R) studies, for

the maritime mobile service, supporting e

navigation;

3. to consider regulatory provisions, if any, based on

the results of ITU R studies, referred to in invites

the ITU Radiocommunication Sector below, to

support the introduction of additional satellite

systems into the GMDSS.

Under point 1) the following issues will be

considered:

− removal of the obsolete Narrow Band Direct

Printing (NDBP) telegraphy system from the

GMDSS in all associated MF and HF bands

(amendments to Appendices 15 and 17 RR);

− introduction of a new ACS (Automatic Connection

System) system to the RR, which would use the

marine MF and HF bands;

− including the NAVDAT system frequencies in the

HF and MF bands in Annex 15 RR and making

appropriate changes to Art. 5, 32, 33 and 52 RR;

− ensuring protection in RR for frequencies used by

AIS-SART (Automatic Identification System -

Search And Rescue Transmitter);

− regulatory actions in response to IMO's decision to

remove EPIRBs using frequencies other than 406

MHz ("non-406 MHz EPIRBs") from the GMDSS.

3 TECHNICAL ASPECTS OF GMDSS

MODERNIZATION

The most important proposals for introducing new or

modifying existing marine radio communication

systems are presented below.

3.1 New satellite operators

According to the current regulations, in order for a

satellite system (operator) to be considered as meeting

the requirements of the SOLAS Convention (GMDSS),

it has to meet the requirements specified in IMO

Resolution A.1001(25) “Criteria for the provision of

mobile satellite communication systems in a global

maritime distress and safety system (GMDSS)” [8].

Current provisions of the SOLAS Convention and the

above Resolution are very strict, e.g. they require

global coverage for operations [8]. In order to change

this, SOLAS Chapter 4 was modified to ensure actual

access to the GMDSS for other satellite service

providers (see point 2.1). In the above context, the

issue of frequency availability for new GMDSS

operators was considered in point 1.8 of the WRC-19

and will be considered in point 1.11 of the WRC-23.

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During the work on the modernization of GMDSS,

all IMO documents applicable to Inmarsat were

reviewed to adapt them to new GMDSS satellite

service providers. In 2018 the MSC 99 agreed that

Iridium Satellite LLC had satisfied the established

criteria to receive recognition as a mobile satellite

communication service provider in the Global

Maritime Distress and Safety System (GMDSS) and

adopted a Statement of Recognition of the Maritime

Mobile Satellite Services provided by Iridium Satellite

LLC, which recognizes the services provided by the

Iridium Safety Voice, Short-Burst Data and enhanced

group calling services, for use in the GMDSS. The

Iridium constellation connects 66 cross-linked

satellites in Low-Earth Orbit, providing reliable

coverage even in adverse weather around the entire

globe, including over the Arctic and Antarctic waters

in Sea Area A4 (Fig. 2) [9].

Figure 2. Iridium constellation showing the six orbital

planes [9]

At the same session the MSC also adopted a

Statement of Recognition of Maritime Satellite

Services provided by Inmarsat Global Ltd, for use in

the GMDSS. The statement recognizes services

provided by the Inmarsat Fleet Safety service, in the

coverage area under the Inmarsat-4 Middle East and

Asia (MEAS) region satellite. Approved by the IMO

Inmarsat Fleet Safety is a maritime data service that

supports GMDSS compliance for voice and data

distress, and urgency and safety communications.

Combining a Maritime Safety Terminal (MST) with

existing FleetBroadband or Fleet One data services,

Fleet Safety is the significant advance in maritime

safety. Fleet Safety offers a full suite of GMDSS

applications such as Distress Alerting, Priority

Messaging, reception of Maritime Safety Information,

priority Short Access Codes such as 38-Medical

Assistance. New innovative safety features are also

included such as Distress Chat with MRCCs and

retrieval of historic Maritime Safety Information.

Following the assessment and evaluation of an

application by China Transport Telecommunication

Information Group Co. Ltd. (CTTIC) to recognize the

BeiDou Message Service System (BDMSS) for use in

the GMDSS, in November 2022the, MSC 106 adopted

an MSC resolution on Statement of recognition of the

maritime mobile satellite services provided by CTTIC

through BDMSS. The recognition is currently limited

to a coverage area within 75°E to 135°E longitude and

10°N to 55°N latitude. IMSO will continue to monitor

the implementation of BDMSS and will report to the

Committee when the Public Services Agreement with

CTTIC has been concluded and the Letter of

Compliance has been issued to mark the

commencement of services.

3.2 Terrestial radio communication

Without a doubt, VHF radiotelephones will remain a

highly useful component of maritime radio

communications. HF radio communications will

remain a required communication system for sea area

A4. It is well known that HF communication is highly

varied and difficult due to variable ionospheric

propagation. A solution to this problem is the use of

ACS (Automatic Connection System). An example of

such a system is automatic frequency scanning and

automatic link establishment (ALE) systems,

improving the success of using HF communication.

Automatic link establishment (ALE) equipment

transmits signals to other stations on a network on

one or more of a pre-arranged list of frequencies. Link

assessment data is stored in an internal database and

used to establish communications on the frequency

most suited to the propagation environment. The ALE

system requires the prior assignment of a suite of

frequencies. These frequencies vary in number but, in

the interests of establishing the link as rapidly as

possible, the number is kept reasonably small (e.g.

four to seven). The ideal adaptive system uses real-

time ionospheric information to modify the suite of

frequencies being evaluated.

Another analysed issue was the use of NBDP in

sea areas A3 and A4. It was found that reception of

maritime safety information (MSI) in the HF band

remains necessary, but it can be acquired by means

other than NBDP, and that this technology will not be

required to fulfil any other GMDSS function.

However, existing NBDP devices can be left to receive

MSI if the ship is not equipped with other devices

fulfilling this function.

To summarise, the application of the proposed

technological progress may lead to easier and more

effective use of the MF/HF bands.

3.3 New communication technologies

The detailed GMDSS review clearly indicates the need

to use new technologies. The main examples of such

new technology are systems NAVDAT and VDES.

Navigational Data (NAVDAT) is the radio system,

for use in the maritime mobile service, operating in

the MF (500 kHz) and HF bands for digital

broadcasting of maritime safety and security related

information from shore-to-ship [6, 7]. The NAVDAT

system uses a time-slot allocation similar to the

NAVTEX system which could be coordinated by IMO

in the same manner. That system can also work on

Single Frequency Network (SFN). In this case

transmitters are frequency synchronized and the

transmit data must be the same for all transmitter. The

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NAVDAT digital system offers a broadcast

transmission of any kind of message from shore to

ships with possibility of encryption. Any broadcasting

message should be provided by a secure and

controlled source.

Message types broadcast can include, but are not

limited to, the following:

− safety of navigation;

− security;

− piracy;

− search and rescue;

− meteorological messages;

− piloting or harbour messages;

− vessel traffic system files transfer.

These messages are broadcasted for the attention

of all ships, a group of ships or in a specific navigation

area. These messages can be addressed to one ship,

using the maritime mobile service identity (MMSI) as

well. The NAVDAT system is organized upon five

vectors performing the following functions [6, 7]:

1. System of information and management (SIM):

− collects and controls all kinds of information;

− creates message files to be transmitted;

− creates transmitting programme according to

message files priority and need of repetition.

2. Shore network:

− assures the transportation of the message files

from sources to the transmitters.

3. Shore transmitter:

− receives the message files from SIM;

− translates message files to orthogonal frequency

division multiplexing (OFDM) signal;

− transmits RF signal to the antenna for broadcast

to ships.

4. Transmission channel:

− transports the RF signal.

5. Ship receiver:

− demodulates the RF OFDM signal;

− reconstructs the message files;

− sorts and makes the message files available for

the dedicated equipment according to the

message files applications.

Figure 4 shows the diagram of the NAVDAT

broadcast chain [10].

Figure 4. The diagram of the NAVDAT broadcast chain [10]

The SIM term includes:

− all the sources that deliver file messages (e.g.

meteorological office, safety and security

organizations, etc.);

− the file multiplexer which is an application

running on a server;

− the file multiplexer manager;

− the shore transmitter manager.

All the sources are connected to the file

multiplexer through a network. The shore network

can use a broadband link, a low data rate link or a

local file sharing.

A coastal transmitting station consists of this

minimum configuration:

− one local server connected to a protected access;

− one OFDM modulator;

− one RF amplifier;

− one transmit antenna with matching unit;

− one GNSS receiver or atomic clock for

synchronization;

− one monitoring receiver with its antenna.

A typical NAVDAT digital receiver is composed of

several basic blocks:

− reception antenna and GNSS antenna;

− RF front end;

− demodulator;

− file demultiplexer;

− controller;

− power supply.

NAVDAT MF ship receiver performance

specifications has been showed on Table 2 [6].

Table 2. Performance specifications of NAVDAT MF ship

receiver

________________________________________________

Frequency band 495 to 505 kHz

Adjacent channel protection > 40 dB @ 5 kHz

Noise factor < 20 dB

Usable sensitivity for BER = 10−4 < −100 dBm

after error correction

Dynamic > 80 dB

Minimal usable RF field (with adapted 25 dB(µV/m)

receiving antenna)

________________________________________________

The system uses Orthogonal Frequency-Division

Multiplexing (OFDM) which is a modulation

technology for digital transmissions. In the 10 kHz

channel bandwidth with RF propagation, the raw data

rate available for the data stream (DS) is typically

around 25 kbit/s with 16-QAM signal.

Another new communications technology planned

for use in the e-navigation and in the modernized

GMDSS is the VHF Data Exchange System (VDES).

The VHF Data Exchange System (VDES) was

developed by International Association of Marine

Aids to Navigation and Lighthouse Authorities

(IALA) to address emerging indications of overload of

the AIS VHF Data Link (VDL) and simultaneously

enabling a wider seamless data exchange for the

maritime community. The initial concept of VDES

includes the function of the Automatic Identification

System (AIS), Applications Specific Messages (ASM),

VDE terrestrial component and VDE satellite

component. The VDES is one of the potential elements

of e-navigation. The VDES is capable of exchanging

ASM, facilitating numerous applications for safety

and security of navigation, protection of marine

environment, efficiency of shipping and others. The

VDES will prospectively have a significant beneficial

impact on the maritime information services

including Aids to Navigation (AtN) and Vessel Traffic

145

Service (VTS) in the future. It can potentially provide

local MSI.

The VDES concept includes a satellite component.

This system component might be suitable to be used

for the transmission of MSI information in remote

areas [5].

Insufficient study on sharing and compatibility

between the VDE satellite component and incumbent

services in the same and adjacent frequency bands

was the cause that the spectrum issue could not be

resolved at World Radiocommunication Conference

in 2015 (WRC-15). Consequential to WRC‐15, the

ITU standard for VDES, Recommendation ITU‐R

M.2092‐0, was approved in 2016. An outstanding

issue regarding the satellite component for VDE

channels was approved at WRC-19 (see point 2.2).

VDES builds on the experience gained through the

development of AIS, and provides the capability to

communicate to [4]:

− a specific vessel (addressed);

− all units in the vicinity (broadcast);

− a group of vessels (addressed); and

− a fleet of vessels (addressed).

The VDES should improve the safety of life at sea,

the safety and efficiency of navigation, and the

protection of marine environment and enhance

maritime safety and security. These goals will be

achieved through efficient and effective use of

maritime radiocommunications, incorporating the

following functional requirements [4]:

− as a means of AIS.

− as a means of radiocommunications equipment

through exchange of digital data between ship to

ship, ship to shore including satellite, via AIS,

ASM and VDE.

− as a means of applications external to the VDES

equipment itself. These applications use AIS, ASM

or VDE separately or combined.

In order to meet the above functional

requirements, the ship's VDES device should include

[4]:

− antenna(s), capable of transmitting and receiving

data through terrestrial and satellite link;

− an AIS as set out in resolution MSC.74(69) Annex 3

[12];

− a multi-function data communication and timing

process that is interoperable with AIS, ASM and

VDE;

− a multi-function transmitter, capable of operating

on the designated AIS, ASM and VDE frequencies;

− multi-function receivers, capable of operating on

the designated AIS, ASM and VDE frequencies;

− a means to automatically input data from other

sources;

− a means to automatically output data to other

devices;

− a means of ensuring the integrity of the data;

− a means to automatically or manually update the

device software as needed;

− functionality of a built-in test equipment (BITE);

and

− GNSS receiver to support AIS and to possibly

serve as a secondary source of Positioning

Navigation and Timing (PNT).

IMO identifies following the Maritime Services in

the context of e-Navigation as defined by IMO e-

navigation strategic implementation plan (SIP) and

their updated E-Navigation Strategy Implementation

Plan - Update 1 (IMO MSC.1/Circ.1595)[9]:

− VTS Information Service (INS);

− Navigation Assistance Service (NAS);

− Traffic Organization Service (TOS);

− Local Port Service (LPS);

− Maritime Safety Information (MSI) service;

− Pilotage service;

− Tugs service;

− Vessel Shore Reporting;

− Telemedical Maritime Assistance Service (TMAS);

− Maritime Assistance Service (MAS);

− Nautical Chart Service;

− Nautical Publications Service;

− Ice Navigation Service;

− Meteorological Information Service;

− Real-time hydrographic and environmental

information Services; and

− Search and Rescue Service.

It should be emphasized that the VDES satellite

component will offer additional communication in the

polar regions and other remote areas for the above use

cases. All these use cases are related to e-navigation

and GMDSS modernization.

4 CONCLUSIONS

The modernization of the GMDSS was closely

connected with the development of the e-navigation

project and the detailed role of the

radiocommunication in this process. Undoubtedly,

the ICT network of the modernized GMDSS will be

one of the most important elements of e-navigation.

The main issue in the work on the modernization

of GMDSS was the preparation of good changes to the

SOLAS Convention and appropriate changes to the

Radio Regulations. It should be noted that it was very

important that the work on the amendments to the

Radio Regulations was correlated with the work of

the IMO on the modernization of the GMDSS system.

In addition, in this work it was very important to

ensure that it would be a continuous and open

process to ensure that it remains modern and fully

responsive to changes in requirements and technology

development and that it meets the expected

requirements in the field of e-navigation. To ensure

this, it was also necessary to create a mechanism,

more than hitherto, for the continuous evolution of

maritime radiocommunications (GMDSS) in a

systematic way. In this approach to the development

of the GMDSS, it was very important that the integrity

of the GMDSS was not compromised.

According to the author, taking into account the

results of the modernization of GMDSS, both in terms

of legal and technical changes, and especially the

modernization of existing systems and devices and

the introduction of new communication technologies,

the above has been fulfilled. For example, the VDES

and NAVDAT systems will make a significant

contribution to digital communications for e-

navigation and the modernization of the Global

146

Maritime Distress and Safety System (GMDSS) (See

Chapter 3.3).

It should be noted that the key to the success of the

GMDSS modernization project will be not only the

timeliness of legal works (see Introduction), but also

the timeliness of the implementation of the adopted

changes.

In the above context, it should be noted the

reported problems with the availability of new

GMDSS radio equipment from 1 January 2024 [11].

The performance standards in resolutions

MSC.511(105) on Performance standards for

shipborne VHF radio installations capable of voice

communication and digital selective calling and

MSC.512(105) on Performance standards for

shipborne MF and MF/HF radio installations capable

of voice communication, digital selective calling and

reception of maritime safety information and search

and rescue related information, require the

development of new equipment with some new

features.

In addition, in the case of shipborne VHF

installations, further definition is required from the

ITU on interface matters, and these are currently still

under study within the ITU.

In the case of shipborne MF and MF/HF radio

installations, resolution MSC.512(105) introduces the

new feature of the Automatic Connection System (See

Chapter 3.2). This will require frequencies for the

channels for its operation which are intended to be

made available by the ITU World

Radiocommunication Conference due to be held from

20 November to 15 December 2023 (WRC-23). These

frequencies should then be available in the new

edition of the Radio Regulations which will probably

come into force in January 2025.

The result of the issues above is that, regrettably,

the manufacturing industry finds itself unable to meet

the date of 1 January 2024 for new installations of

shipborne VHF radios and shipborne MF and MF/HF

radios complying with the provisions of resolutions

MSC.511(105) and MSC.512(105). According to the

author, to solve this problems, January 1, 2026 should

be taken as a realistic date for the installation of these

new devices on ships.

And finally, according to the author, the key to the

final success of the GMDSS modernization and e-

navigation projects will be not only the timeliness of

works and implementation, but above all the

flexibility of both systems, allowing for more efficient

introduction of further changes, taking into account

technological progress.

REFERENCES

[1] Report of the Maritime Safety Committee on its 81

session, International Maritime Organization (IMO),

2006

[2] Korcz, K., Some Aspects of the Modernization Plan for

the GMDSS, International Journal on Marine Navigation

and Safety of Sea Transportation, vol. 11, no. 1, 2017

[3] RESOLUTION MSC.496(105), AMENDMENTS TO THE

INTERNATIONAL CONVENTION FOR THE SAFETY

OF LIFE AT SEA, IMO, 2022

[4] G1117 - VHF DATA EXCHANGE SYSTEM (VDES)

OVERVIEW, Edition 3.0, IALA, 2022

[5] Recommendation ITU-R M.2092-1, Technical

characteristics for a VHF data exchange system in the

VHF maritime mobile band, ITU, 2022

[6] Recommendation ITU-R-M.2010, Characteristics of a

digital system, named Navigational Data for

broadcasting maritime safety and security related

information, ITU, 2012

[7] Recommendation ITU-R M.2058, Characteristics of a

digital system, referred to as navigational data for

broadcasting maritime safety and security related

information from shore-to-ship in the maritime HF

frequency band, ITU, 2014

[8] Resolution A.1001(25), Criteria for the provision of

mobile satellite communication systems in a global

maritime distress and safety system (GMDSS), IMO

[9] NCSR 3/11, ANALYSIS OF DEVELOPMENTS IN

MARITIME RADIOCOMMUNICATION SYSTEMS

AND TECHNOLOGY - Recognition of Iridium mobile

satellite system as GMDSS service provider, IMO, 2015

[10] Korcz, K., Some Aspects of the Modernization Plan for

the GMDSS, International Journal on Marine Navigation

and Safety of Sea Transportation, vol. 11, no. 1, 2017

[11] NCSR 10/21/5, ANY OTHER BUSINESS - Delays

affecting the availability of new GMDSS radio

equipment from 1 January 2024, IMO, 2023