International Journal
on Marine Navigation
and Safety of Sea Transportation
Volume 5
Number 2
June 2011
Technical progress of modern digital navigating and
communication technologies has provided new tech-
nical systems appeared and maintained in practical
navigation such as: Global Maritime Distress and
Safety System (GMDSS), Automatic Identification
System (AIS), Global Navigational Satellite System
(GNSS), Electronic Chart Display and Information
System (ECDIS), etc. At the same time keeping and
increasing the level of safety at sea in the conditions
of vessel’s saturation by navigating and radioelec-
tronic devices demands the effective operation of the
specified systems under common fatigue of the of-
ficer of the watch (OOW).
Not always the practical navigational tasks can be
satisfactory provided within the existing shipborne
equipment. In particular there is misalignment be-
tween decision time and reaction time. It is neces-
sary to provide real time operational procedures.
In Оdessa National Maritime Academy at the
Electrical Engineering and Radio Electronics Facul-
ty, (Maritime Radiocommunications chair) in the
general direction of safety navigation enhancement
and development of electronic navigation (e-
navigation) since the end of 90
years scientific-
practical works are carried out in the following di-
1 Improving of the GMDSS Narrow-Band Direct
Printing interface for telex communication;
2 Radar detection of high-speed vessels with small
surface of reflection against interferences from a
water surface;
3 Automatic identification of VHF radiotelephone
transmissions in real time;
4 Increasing of DSC efficiency by means of inte-
gration with AIS and ECDIS ship systems.
In the present report some results of researches in
the fourth direction are presented. The obtained re-
sults have been formulated and submitted by
Ukraine in the form of the technical proposal for
discussion of 14
Session of IMO Subcommittee on
Radiocommunications, Search and Rescue (COM-
SAR), that have been passed in London in February,
2010 [1]. The given proposal was unanimously sup-
ported by the participants of the Session.
Digital Selective Calling (DSC) is one of the
basic features of GMDSS radiocommunication sub-
systems. In accordance with International Telecom-
munication Union Recommendation [2] all radio-
telephone transmissions of any priority (distress, ur-
gency, safety and routine) must be preceded by the
proper digital selective call. Nevertheless, the proce-
dures of radiocommunication with the use of DSC
are often neglected either in cases of distress or with
other priorities. In particular, VHF channel 16 is of-
ten used incorrectly for any calls attributed with rou-
tine priority as it was foreseen in the old system pro-
cedure instead of using DSC on channel 70.
The reasons for such neglect were analysed in
numerous documents of COMSAR, for example [3].
The main reason for the DSC communication proce-
dure neglect is described in this document as the
navigators’ nonconformity with the DSC procedures
based on:
difficulty of manual DSC forming procedure;
different DSC interface provided by manufac-
the overload of the DSC call forming menu by
secondary, non-important functions; and
Increasing Maritime Safety: Integration of the
Digital Selective Calling VHF Marine
Radiocommunication System and ECDIS
M.V. Miyusov, V.M. Koshevoy & A.V. Shishkin
Odessa National Maritime Academy, Ukraine
ABSTRACT: A general project for simplification of VHF DSC radiocommunication for navigators and for
increasing DSC efficiency by integration of the DSC VHF radio equipment and the AIS ECDIS vessel’s
system is presented. Proposed measures are to contribute to further developments in maritime radiocommuni-
cation systems, technology and progress of e-navigation strategy.
limited space for all DSC format visualization,
Navigators as usual neglect DSC process and di-
rectly pick up the telephone on channel 16. Such
elimination of DSC doesn’t accelerate reliable and
correct VHF communication because a lot of time
may be needed for called/calling vessel’s verbal
specification among other vessels.
An important objective of the VHF radiocommu-
nication improvement is the development and im-
plementation of such technical improvements which
could give an ability to:
1 simplify the process of providing DSC radio-
communication to, practically, the equivalent ac-
tions in terms of time and number of operations,
as to the usual radio-telephone receiver picking
up procedure; and
2 select the called/calling vessel among others
which are displayed on the electronic navigation-
al chart. This element is specifically important for
the urgent reaction of the watch officer on the
called vessel under difficult navigation condi-
tions, i.e. to provide the automatic identification
of the called/calling vessel in the live navigation
The completion of these two tasks can be
achieved within the frames of the currently used
vessel equipment through the integration of the VHF
DSC controller and the navigation equipment com-
posed of the Automatic Identification System (AIS)
and the Electronic Chart Display and Information
System (ECDIS). In this case all of the basic func-
tions of integrated systems are preserved.
Currently AIS is an obligatory equipment to be
carried on board all vessels. ECDIS has been man-
dated recently, nevertheless even now it is widely
used as a supplement to the traditional paper charts.
AIS provides for the exchange of information which
includes an identification number (MMSI). ECDIS,
while operating with AIS, enables it to indicate ves-
sels on a navigation display within the AIS operating
area, i.e. approximately 30 nautical miles, and to re-
flect them on electronic navigational charts.
The combination of the VHF DSC equipment
with the AIS - ECDIS system allows:
1 to eliminate, practically, the procedure of DSC
forming while substituting manual operations by
a computer mouse “click” on the ECDIS display;
2 to provide the authentication of a calling vessel
on the electronic chart and thus to make the pro-
cess of attachment of the called/calling vessel to
the navigation situation automatically. A calling
vessel can be indicated on the display by a blink-
ing mark which will allow OOW (officer of the
watch) of the called vessel to quickly estimate the
navigational situation and make an effective deci-
The unique character of the vessel’s authentica-
tion is provided by the presence of vessel identifier
(MMSI) both in DSC and AIS. In other words, it
means that the calling vessel is automatically at-
tached to the current navigation situation represented
on a navigation display.
During the manual preparation of the call proce-
dure, as it is provided in the existing system, an op-
erator has to make an individual call to a ves-
sel/coast station and for this purpose has to enter a
nine-character long digital identifier (MMSI) and
working channel number. While doing this, about 20
pressings of the DSC controller keyboard buttons are
required. More difficult calls require more key
pressing. The proposed method gives the ability to
form a call through a mouse click only on the chosen
vessel (or the coast station). The series of parame-
ters, for example, the working channel number, can
be set by default (or can be chosen manually if nec-
essary). The entering of the MMSI is not required in
the proposed method because it can be sent from the
AIS - ECDIS system to the DSC controller automat-
Integration of the DSC - VHF and AIS - ECDIS
may be realized through a separate interface block
connected to the DSC equipment of any equipment
manufacturers. Replacement of the DSC equipment
is thus not required. Appropriate simplified scheme
is presented in the figure 1. The scheme includes al-
so navigational sensors and devises that in practice
are connected to ECDIS Workstation. Connection of
DSC VHF equipment and ECDIS is implemented by
means of bidirectional interface.
Figure 1. General scheme of ECDIS inputting and VHF DSC
Integration of the DSC - VHF and AIS - ECDIS
requires no changes to the existing radiocommunica-
tion operational procedures. All regular DSC form-
ing and viewing functions are saved. What is essen-
tial is that the present manual method of
forming/viewing calls will be preserved as a sup-
plementary means to the automatic method of form-
ing/viewing calls in the AIS - ECDIS system.
VHF DSC integration with the AIS-ECDIS will
ensure further enhancement of safety of navigation
while simplifying the navigator’s interface with ra-
diocommunication and navigational equipment and
accelerating actions of operator.
The practical problem on the way of such kind of
integration is the necessity of ECDIS modernization
by means ECDIS - DSC connection and interaction
in both directions. Corresponding apparatus means
of interface and software tools are developing.
This suggestion is fully compatible with the e-
navigation development strategic direction which
envisages further development of means of radio-
communications and navigation and the implementa-
tion of modern digital information technologies in
Technical implementation of this suggestion is al-
so compatible with the new regulations for the man-
datory carriage requirement of ECDIS.
[1]. Proposal for simplification of VHF DSC radiocommunica-
tion and increasing DSC efficiency. Submitted by Ukraine /
AND SEARCH AND RESCUE. 14th session, Agenda item
7. COMSAR 14/7, 27 October 2009
[2]. Recommendation ITU-R M.493 “Digital Selective-Calling
System for Use in the Maritime Mobile Service”.
[3]. Simplification of DSC equipment and procedures. Submit-
SAR 8/4/1, 27 November 2003.