Annex 3
User interface for operation of shipborne equipment
1 General
The user interface for
operation of the DSC equipment should be so designed that it will be easy for
the operator onboard the ship to operate the equipment and to compose and
initiate the types of DSC messages provided for by the equipment.
2 Definitions:
2.1
automated
procedure: the term given to describe the set of actions
necessary to complete the objective of an initiating DSC message or non DSC
communication event. . Four
DSC automated procedures are designed to process these. They are the receiving
of distress DSC messages, the receiving of non distress DSC messages, the
sending of distress DSC alert attempts and the sending of non distress DSC
messages. In addition a fifth procedure
is designed to handle non DSC communication events.
These automated
procedures are called:
- Received distress automated procedure
- Sending distress automated procedure
- Received non-distress automated procedure
- Sending non-distress automated procedure
-
Communications automated procedure.
2.2
default: a value
selected or an action taken by the equipment software in the absence of any
operator input.
2.3
DROBOSE: Distress
Relay On Behalf Of Someone Else
2.4
engaged: the
term used to indicate that the equipment is busy handling an automated
procedure.
2.5
factory default: A default
value that is set by the manufacturer such that the field or behavior is
defined prior to any operator intervention.
2.6
standby: the
term used to indicate that the equipment is not handling an automated
procedure, either active or on hold, but is able to receive DSC messages.
2.7
top
level: top level means that items, buttons, or functions are
present and visible without requiring any action by the operator (such as
scrolling, opening up menus, or removing any obscuring covers, etc.).
3 Controls
3.1. Dedicated
Distress Button to initiate
the sending of the distress alert attempt.
This button
should have at least two independent actions.
Lifting of the protective lid is considered the first action. Pressing the distress button is considered as
the second independent action.
This button should be red in colour and marked “DISTRESS”. Where a
non-transparent protective lid or
cover is used, it should also be marked “DISTRESS”.
The cover should be protected
against inadvertent operation with a spring loaded lid or cover permanently
attached to the equipment by e.g. hinges. It should not be necessary for the
user to remove seals or to break the lid or cover in order to operate the
distress button. This button should be used only for this purpose and it should be able to perform this
function at all times.
Use of the button without any previous operator actions to compose the alert
should initiate the default distress alert attempt. The “default distress alert
attempt” consists of ‘undesignated” for the nature of distress, radio telephony
for the communication mode, and on HF the transmission of the attempt uses the
multi frequency method including all six bands.
The distress button
should have priority over all DSC procedures.
3.2 The following controls,
buttons or functions should be provided and
visible at the top level while the equipment is in standby:
3.2.1. Distress
Function for composing
distress alert attempts other than the default distress alert attempt where the
operator is able to
– select the nature of distress (the
factory default should be undesignated distress),
– on HF select the communication mode
(the factory default should be telephone),
– on HF select the method and
frequencies of transmission (the factory default should be the multi frequency
method on all six bands),
– check the content of the position and
time of position information and to manually enter this information if not
correct,
prior to initiating
the sending of the distress alert attempt with the Dedicated Distress Button.
3.2.2 Call
Function for composing non distress
DSC messages.
3.2.3 Distress
Relay On Behalf of Someone Else Function for composing and relaying the occurrence of a distress event obtained
by non DSC means.
3.3 The following controls, buttons or functions
should be provided and be
visible as noted:
3.3.1 Cancel/Esc/Exit/or
equivalent for returning to a
previous menu level from any state of the equipment
3.3.2 Enter/Accept/Next/Touch/Press
or equivalent for
3.3.2.1 accepting a menu item or
3.3.2.2 going to the next step.
4 Display
of messages in plain language
The headings and
content of messages should be shown in plain language , for example:
– ‘Radio telephone’ instead of J3E,
–
‘busy’
instead of ‘telecommand 2: 102’.
5 Transmission
of DSC messages
5.1 DSC
Message composition features
The facilities for
choosing and composing DSC messages should be so arranged that it is possible
for the operator quickly and precisely to:
5.1.1 compose
the content of the DSC message,
5.1.2 review
and correct, if needed, the content before transmitting the DSC message.
5.2 Operational
guidance to the operator
5.2.1 The
operator should only be able to compose the types of DSC messages which are
specified in the Tables 4.1 – 4.10.2 of Annex 1.
5.2.2 The
equipment should automatically propose the next step for composing the DSC
message, for example, when pressing the Enter/Accept/Next/Touch/Press button or equivalent, if not visible from the
context or on the display.
5.3 Defaults
Where options for the
items in the DSC message exist (see Annex 1, Tables 4.1 – 4.10.2), the factory
default values should be as follows:
after the operator
selects the option to compose a non distress DSC message
– if the operator has the option to
select a format (destination address) the default format should be ‘individual
(120)’,
– if the format (destination address)
is either individual (120), a group of ships (114), or a semi-automatic phone
call (123), the default MMSI should be some internal indicator that the MMSI is
invalid and needs to be entered before transmission can occur,
– if the format (destination address)
is an area (102), the default area should be a circle of radius 500 nautical
miles centered on the ship,
– if the operator has the option to
select a category (priority) the default category should be ‘routine’ unless
the routine priority is not allowed (such as in an area or all-ships DSC
message) in which case it should be ‘safety’,
– if the operator has the option to
select the type of subsequent communication the default value should be radio
telephony,
– if the operator has the option to
select a frequency or channel for the subsequent communication the default
value should be a non distress frequency or channel consistent with the means
of subsequent communication and on MF/HF in the same band as the DSC message
transmission,
–
on MF/HF
if the operator has the option to select a the frequency of the DSC
transmission, default value should be 2,177 KHz,
–
on MF if the operator has the option to select
a the frequency of the DSC transmission,default value should be 2,177 KHz,
–
on HF if the operator has the option to select
a the frequency of the DSC transmission, default value should be in the 8 MHz
band,
– all other parameters, for example the
position, self ID, time of position, and end of sequence character, should be
automatically entered by the equipment,
– the category should not be
‘remembered’ when the call composition option is selected at a later time but
should be reset to the factory default; this requirement does not mean the
equipment is unable to provide the operator with the option to send
pre-composed, customized DSC messages with a single action,
– for example, if there is only a
single ‘call’ button, menu selection, or equivalent for initiating a non
distress DSC message, the default DSC message should have format ‘individual’
and category ‘routine’,
after the operator
selects the option to compose a Distress Relay On Behalf Of Someone Else
(DROBOSE)
– if the operator has the option to
select a format (destination address) the default format should be ‘individual
(120)’,
– if the format (destination address)
is individual (120), the default MMSI should be the all coast stations MMSI 009990000 [if such an
MMSI has international acceptance]. Otherwise it should be some
internal indicator that the MMSI is invalid and needs to be entered before
transmission can occur,
– if the format (destination address)
is an area (102), the default area should be a circle of radius 500 nautical
miles centered on the ship,
– the default nature of distress should
be ‘undesignated (107)’,
– the default MMSI for the vessel in
distress should be ‘unknown (five 126’s)’,
– the default position and time of
position should be unknown,
–
the
default means of subsequent communication should be radio telephony,
–
on MF/HF
the default band of the DSC transmission should be on the 2 MHz band,
–
on MF the default band of the DSC transmission
should be on the 2 MHz band,
– on HF the default band of the DSC transmission should be
on the 8 MHz band,
– all other parameters, for example
the, self ID, the distress relay telecommand 1 parameter, the category
(distress), and end of sequence character should be automatically entered by
the equipment,
– the format, MMSI of the vessel in distress, the
nature of distress, the position and time of position should not be
‘remembered’ when the DROBOSE composition option is selected at a later time
but should be reset to the defaults.
5.4 Other items
5.4.1 If
the called station is a ship station or a group of ship stations the equipment
should request input of a channel number (frequency in case of MF). The
equipment should assist the operator by suggesting a suitable inter-ship
channel, on VHF for example channel 6.
5.4.2 Automated HF subsequent communication channel selection for non distress
DSC messages. There is a simplex set and duplex set (contains the distress
channels) for HF for both voice (3000 Hz) and data (500 Hz) communication
modes. Selection of the appropriate channel from these sets should follow the
following
– The band of the communication channel should be
the band of the DSC message
– The telecommand 1 parameter
determines the choice of voice or data channels
– DSC messages directed to a coast
station (i.e. MMSI commencing 00) should let the coast station decide
– All other DSC messages should select
a channel from the simplex frequencies
5.4.3 Use of the distress channels should be
avoided and for routine communications use of the distress channels should not
be allowed.
Annex 4
Automated
procedures in shipborne equipment
1 General
Automated procedures
are the incorporation of ITU-R recommended DSC operational procedures into
equipment software.
The equipment should
initiate (start) one of five automated procedures whenever the equipment
becomes engaged in a new communication event. Four of these automated
procedures handle events initiated by sent and received DSC messages and the
fifth automated procedure handles radio telephony established by non DSC means.
One of these five automated procedures is initiated
by
a) sending a distress alert,
b) receiving a DSC message containing
distress information,
c) sending an individually addressed
relay containing distress information,
d) sending distress relay on behalf of
someone else,
e) sending a DSC message containing no
distress information,
f) receiving a DSC message containing no
distress information,
g) engaging in traffic initiated by non
DSC means.
Once initiated by any
of the events listed in a-g, the automated procedure should handle all the
tasks required to satisfy the objectives of the initiating event. These tasks
should include the handling any subsequent DSC messages that may be pertinent
(relevant) to the objectives of the automated procedure and appropriately
updating the automated procedure, providing the operator with any possible
options, and keeping the operator informed of the progress until either the
operator terminates the automated procedure or conditions warrant that the
automated procedure self terminates. Automated procedures should be able to be
run in parallel. Whereas all DSC automated procedures continuously monitor the
watch receiver only one active automated procedure has control of the
transmitter and general receiver. The
reception of any DSC message not pertinent to an automated procedure should not
disrupt that procedure but should be appropriately allocated to the appropriate
ongoing automated procedure or initiate a new automated procedure.
2 Definitions:
2.1 acknowledged: when used to describe an automated procedure
it indicates that the objective of the initial DSC message has been achieved.
2.2 active: the term used to describe an
automated procedure which has control of the general receiver and transmitter
and is thus able to engage in subsequent communications and receive DSC
messages on both the watch receiver and general receiver.
2.3 automated
procedure: the term given to
describe the set of actions necessary to complete the objective of an
initiating DSC message or non DSC communication event. Four
DSC automated procedures are designed to process these. They are the receiving
of distress DSC messages, the receiving of non distress DSC messages, the
sending of distress DSC alert attempts and the sending of non distress DSC
messages. In addition a fifth procedure
is designed to handle non DSC communication events.
These automated procedures are called:
- Received distress automated
procedure
- Sending distress automated
procedure
- Received non-distress automated procedure
- Sending non-distress automated
procedure
- Communications automated
procedure.
2.4 critical
errors: a set of information
characters obtained from one or more received DSC messages is considered to
have critical errors if the automated procedure needs information characters
from that set in order to proceed or perform any task, but the required
information characters are in error (for example, an acknowledgement cannot be
composed to an individual DSC message that has errors in the sender’s MMSI).
2.5 default: a value selected or an action taken by the
equipment software in the absence of any operator input.
2.6 distress
DSC message: A DSC message or
acknowledgement containing the distress information.
2.7 distress
event: a unique distress
situation identified by two (VHF) or three (MF/HF) parameters of the distress
information; the MMSI of the vessel in distress and the nature of distress and
on MF/HF the mode of subsequent communication.
2.8
distress information: the symbols within a DSC message describing a
distress situation consisting of the MMSI of the vessel in distress, the nature
of distress, the position of the vessel in distress, the UTC time of that
position, and the mode of subsequent communication.
2.9
DROBOSE: Distress Relay On Behalf Of Someone Else
2.10 DX/RX: a notation used to describe the time diversity
structure of DSC messages (see Figure 1 of Annex 1). One has to be careful not
to confuse the ‘RX’ notation when used to indicate the symbol position in the
DSC message structure (as in §4.1 of Annex 1) with its use to indicate
reception (as in §8.3.2 of Annex 1).
2.11 engaged: the term used to indicate that the equipment is busy handling an
automated procedure.
2.12 factory default: A
default value that is set by the manufacturer such that the field or behavior
is defined prior to any operator intervention.
2.13 general
receiver: this unit is the
receiver part of the transceiver used for the reception of all subsequent
communications and on HF the reception of non distress DSC acknowledgements. It
is important to distinguish this unit from the watch receiver (see below).
2.14 identical:
a set of information
characters is considered identical to another set of information characters if
all pairs of corresponding information characters are equal or, if a pair of
corresponding information characters is not equal, one of the pair is in error.
2.15 information
characters: the set of symbols
in the DSC message that contain the items of interest for the recipient and is
used to compute the ECC symbol that terminates the message. These symbols are
repeated in the DX/RX time diversity pattern.
2.16 initial
DSC message: the DSC message
that starts an automated procedure.
2.17 non
distress DSC message: DSC
messages and acknowledgments that do not contain the distress information.
2.18 objective:
when in reference to a DSC
message or automated procedure it is the goal or intent of the item; usually
this goal or intent is to establish subsequent communications or request
information.
2.19 on
hold: the term used to
describe an automated procedure which does not have access to the transmitter
and general receiver and therefore cannot engage in subsequent communications
and is only able to receive DSC messages on the watch receiver.
2.20 operator
options: are any choices the
operator can make while the automated procedure is engaged.
2.21 parallel event handling: the background process of handling a received DSC
message that is not pertinent to the active automated procedure.
2.22 pertinent
to the automated procedure: an
expression used primarily with reference to DSC messages to indicate that the
message has something to do with the procedure and is therefore ‘handled’ by
the procedure. A DSC message is pertinent to an automated procedure if the set
of information characters in the DSC message has the correct values.
2.23 standby: the term used to indicate that the equipment
is not handling an automated procedure, either active or on hold, but is able
to receive DSC messages.
2.24 two-tone
alarm: an alarm consisting of
a repetition of the 2200 Hz frequency for 250 ms followed by a 1300 Hz
frequency for 250 ms. This alarm is used for the initiation of the received
distress DSC automated procedure. The characteristics of this alarm should not
be able to be altered.
2.25 urgency
alarm: an alarm consisting of
a repetition of the 2200 Hz frequency for 250 ms followed by 250 ms period of
silence. This alarm is used for the initiation of the received non distress DSC
automated procedure when the category of the initiating DSC message is
‘urgency’. The characteristics of this alarm should not be able to be altered.
2.26 watch
receiver: this unit is the
separate receiver in DSC radios that continuously monitors the DSC distress
frequencies on MF/HF, 2 187.5 kHz on MF, and channel 70 on VHF. On MF/HF it is
sometimes referred to as the scanning receiver.
3 Tasks
of Automated Procedures
3.1 Tasks common to all automated procedures
handling DSC messages
3.1.1 Handling
alarms:
3.1.1.1 The sounding of any alarm should simultaneously display the reason for
the alarm and the means to silence it.
3.1.1.2 Alarms should sound appropriate to the automated procedure when a
received DSC message either initiates or acknowledges the automated procedure
with the two-tone alarm being reserved for the initiation of the received
distress procedure, and the urgency alarm being reserved for the initiation of
the received non distress procedure when the category of the initiating DSC
message is ‘urgency’.
3.1.1.3 Only the first occurrence of
a received DSC message should sound the alarms described in 3.1.1.2.
3.1.1.4 All received DSC messages that do not sound an alarm as specified in
3.1.1.2 should sound a brief, self-terminating alarm to inform the operator of
the reception.
3.1.2 Displaying
Stages of the Automated Procedure
The automated
procedure should display the stages and/or activity in order to indicate the
progress of the procedure.
3.1.3 Tuning
the radio:
3.1.3.1 Tuning of the general receiver and transmitter for reception or
transmission of required acknowledgments, repeat transmissions, relays, or subsequent
communications should be handled automatically.
3.1.3.2 Any automated tuning action that could potentially disrupt ongoing
subsequent communications should provide the operator with at least a ten
second warning. The operator should then be provided with the opportunity to
pause the action. In the absence of operator intervention the automated action
should proceed.
3.1.4 Displaying
Operator Options
Options should only be
provided at those times the option is appropriate.
3.1.5 Handling
DSC messages not pertinent to the active procedure
The received DSC
message is either allocated to the correct automated procedure running in the
background on hold or initiates a new automated procedure on hold.
3.1.6 Displaying
Warnings
Warnings should be
displayed when the operator attempts to do anything that does not follow the
guidelines given by ITU and IMO. The operator should have the option to go back
to the stage of the automated procedure where the action was taken that caused
the warning.
3.1.7 Handling
DSC messages containing errors
3.1.7.1 A DSC message with errors is pertinent to an automated procedure if the
set of information characters in the DSC message is identical as defined in the “definitions” section to the set of
information characters normally used to determine pertinence.
3.1.7.2 Automated procedures initiated by DSC messages with critical errors
should sound the same alarm they would sound if the DSC message were received
error free but the alarm should self-terminate.
3.1.7.3 Automated procedures
are encouraged to utilize subsequent DSC messages pertinent to the automated
procedure to reduce the number of receive errors in the set of information
characters that are important to the automated procedure. In no case should the
reception of subsequent DSC messages increase the number of errors in the set
of information characters important to the automated procedure.
3.1.7.4 No automated
procedure should allow the transmission of further DSC messages with errors.
3.1.7.5 If critical errors
prevent an automated procedure from setting up an operator option or performing
any automated action, that option should be disabled or that action not
performed.
3.1.7.6 Automated procedures
should not be considered acknowledged until all the critical errors in the set
of acknowledgement information characters have been received correctly or
corrected by repeat reception.
3.1.7.7 Information that is normally displayed that
contains errors should be displayed to the full extent possible; for example,
digits in the MMSI or position information that are received correctly should
be displayed in their correct positions and those that are not should be
indicated by some special error symbol.
3.1.8 Transmission
of DSC messages
Transmission of DSC
messages is should encouraged to use a
prioritized wait scheme. If the channel is not free, and the DSC message is a
distress alert, the alert should be transmitted as soon as the channel becomes
free or after 10 seconds on MF or HF or 1 second on VHF, which ever
occurs first. For all other DSC messages, the automated procedure should wait
for the channel to become free and then delay transmission of the DSC message
for a specified wait time. Distress DSC messages (except for alerts), urgency,
safety, routine and test DSC messages should wait one, two, three, and four
“fixed” units of time plus a random addition described below, respectively,
before attempting to transmit. Transmission occurs if and only if the channel
is still free after this wait time has elapsed, otherwise the process is
repeated. The fixed “unit” of time should be 100 ms on MF and HF and 50 ms on
VHF. The randomly generated component should be some positive integer with
resolution in milliseconds between zero and the fixed interval. On MF/HF the channel is considered free if the receiver hardware or DSP
software is unable to recognize the DSC tones.
3.1.9 Automated
termination
3.1.9.1 Automated procedures should have an automated termination timer which whose factory default values can be
setchanged by the operator.
It should be possible to disable this timer. Unacknowledged sending distress
automated procedures should not have
a termination timer, however after acknowledgement a termination timer is
optional.
3.1.9.2 At least 10 seconds prior to automatic termination, a warning with a
discrete aural alarm should be displayed giving the operator the opportunity to
stop the termination.
3.2 Tasks specific to certain automated
procedures
3.2.1 Tasks
of Automated Procedures initiated by receiving non distress DSC messages:
3.2.1.1 Display of Elapsed time.
The elapsed time since
receiving the initiating DSC message should be displayed or after any requested
acknowledgment has been sent, the elapsed time since sending the
acknowledgement should be displayed. Sending repeat acknowledgments should not
affect the time display.
3.2.1.2 Handling acknowledgments.
3.2.1.2.1 If the equipment has been set up to automatically acknowledge
individually addressed polling, position request, or test DSC messages, no
alarm should sound and the automated procedure should self-terminate.
3.2.1.2.2 All individually addressed DSC messages with subsequent communications
should be automatically acknowledged as a default. In this case the alarm
should sound after the acknowledgement is sent.
3.2.1.2.3 Acknowledgement options should only be made available to the operator
when the received DSC message requests an acknowledgement.
3.2.1.2.4 When acknowledgments are requested the automated procedure should
provide the operator with up to three possible acknowledgement options based
upon the received DSC message as follows:
3.2.1.2.4.1 Able to comply: This option should be provided if the frequencies and
mode of subsequent communication are provided by the received DSC message and
the equipment is capable of handling the requested communications, or if the
received DSC message is a polling, position request, or test that has not been
automatically acknowledged,
3.2.1.2.4.2 Able to comply with a mode or frequency change: This option should be
provided if the received DSC message requests subsequent communications.
3.2.1.2.4.3 Unable to comply: This option should be provided if the received DSC
message contains subsequent communications or is a position request. The
sending of this acknowledgement indicates a refusal and should terminate the
automated procedure.
3.2.1.2.5 The automated procedure should automatically compose the acknowledgement
messages based upon the received DSC message as shown in Figure 2 and Figure 3
of Annex 1.
3.2.1.2.5.1 ‘Able to comply’ acknowledgments should be composed in entirety by the
automated procedure.
3.2.1.2.5.2 ‘Able to comply with a mode or frequency change’ acknowledgements
should only require the entry/selection of a new mode and/or frequency.
3.2.1.2.5.3 ‘Unable to comply’ acknowledgments to DSC messages containing
subsequent communications should only require the entry/selection of one of the
ten telecommand 2 ‘reason’ symbols specified in Table 3 of Annex 1.
3.2.1.2.5.4 ‘Unable to comply’ acknowledgments to position requests if implemented
should only require a single action by the operator to send. The procedure
should automatically place the ‘no information symbol’ in the position and time
messages of the acknowledgement.
3.2.1.2.6 The operator should be able to resend a duplicate of the first
acknowledgement in automated procedures that have subsequent communications.
3.2.2 Tasks
of Automated Procedures initiated by sending a non distress DSC message:
3.2.2.1 Display of elapsed time
The elapsed time since sending the initial DSC message should be
displayed or after the automated procedure has received a requested
acknowledgment, the elapsed time since acknowledgement should be displayed.
Receiving repeat acknowledgments should not affect the time display.
3.2.2.2 Resending the Initial DSC message
3.2.2.2.1 If no acknowledgement is requested the option to resend the initial DSC
message should remain available until the procedure is terminated.
3.2.2.2.2 If an acknowledgement is requested the option to resend the initial DSC
message should remain available until the acknowledgment has been received.
3.2.2.3 Handling the reception of a delayed acknowledgement
If an acknowledgement appropriate
to this automated procedure is received but the operator has terminated the
automated procedure prematurely, the appropriate automated procedure should be
reconstructed based on the acknowledgement and the operator informed of the
situation.
3.2.3 Tasks
of Automated Procedures initiated by receiving a distress DSC message or
sending a distress relay on behalf of someone else:
3.2.3.1 Display of elapsed time
The elapsed time since receiving the initial
DSC message should be displayed or after the automated procedure has been
acknowledged, the elapsed time since acknowledgement should be displayed.
Receiving repeat acknowledgments should not affect the time display.
3.2.3.2 Determining operator options
3.2.3.2.1 On HF the operator should have the option to
set the general receiver and transmitter to any one of the six distress
frequencies of subsequent communication.
3.2.3.2.2 The option to send a relay should always be
available until the automated procedure is terminated.
3.2.3.2.3 Distress alert acknowledgments and relay acknowledgement options
3.2.3.2.3.1 These options should not be made available
until a DSC message has been received that can respond to the acknowledgement.
3.2.3.2.3.2 These options should be available immediately
after reception of the appropriate DSC messages and not wait until certain conditions for their use, such as time
limits, are fulfilled.
3.2.3.2.3.3 Once these options are available, they should
remain available until the automated procedure is terminated.
3.2.3.3 DSC Message composition
3.2.3.3.1 The
automated procedure should automatically compose relays, distress alert
acknowledgments and relay acknowledgments based upon the received DSC messages.
3.2.3.3.1.1 the
distress information should be taken from the distress DSC message which has
the latest UTC time stamp.
3.2.3.3.1.2 Distress alert acknowledgements and relay acknowledgements should
require no data entry by the operator except on HF where the frequency of the
DSC message may be selected,
3.2.3.3.2 relays should only allow the entry of the addressing mode (format) and
destination address and on HF, the mode of subsequent communication and the
frequency of the DSC message,
3.2.3.3.3 on HF the automated procedure should indicate those frequencies on which
DSC messages pertinent to the automated procedure have been received as the
preferred choices, however the operator should be allowed to choose any of the
six distress frequencies.
3.2.3.4 Tuning of the radio after acknowledgment on HF
The automated tuning should cease
upon reception or sending of a distress alert acknowledgement or a distress
relay acknowledgment addressed to multiple stations. However, the operator
should be provided with sufficient information to manually tune to the working
frequencies of the most recently received DSC message.
3.2.3.5 Handling individually addressed relays
3.2.3.5.1 The
sending or receiving of individually addressed relays should initiate their own
automated procedure separate from the automated procedure that may be handling
distress DSC messages concerning the same distress event.
3.2.3.5.2 The
option to send a distress alert acknowledgement should never be available
during this automated procedure.
3.2.3.6 Handling DSC messages with critical errors
If the subsequent communication
parameter of the distress information is received in error, radio telephone
should be assumed and an indication that the parameter was received in error
should be made known to the operator.
3.2.3.7 Handling the self-addressed distress alert acknowledgement
If the MMSI of the sender of a
distress alert acknowledgement is the same as the MMSI of the vessel in
distress, the automated procedure should recognize the message as an attempt to
cancel the distress alert and inform the operator accordingly.
3.2.3.8 Extended DSC sentences
The automated
procedure should be able to successfully receive and decode single frequency
alert attempts that have extended sentence information at the end of some or
all of the individual alerts.
3.2.3.9 MF/HF
Only Scanning for distress DSC
messages on MF/HF
The received distress
automated procedure should scan all six distress DSC channels if not already
doing so.
3.2.4 Tasks
of Automated Procedures initiated by sending a distress alert attempt:
3.2.4.1 Display
of elapsed time
3.2.4.1.1 The time remaining to the sending of the next distress alert attempt
should be displayed prior to acknowledgment by DSC.
3.2.4.1.2 The elapsed time since acknowledgement should be displayed after
acknowledgment by DSC. Receiving repeat acknowledgments should not affect the
time display.
3.2.4.2 Resending of the distress alert attempt
3.2.4.2.1 The
unacknowledged distress alert attempt should be automatically resent after a
3.5 to 4.5 minute wait.
3.2.4.2.2 The
automatic resending of the distress alert attempt should automatically
terminate after acknowledgement by DSC.
3.2.4.2.3 Resent
distress alert attempts should contain updated position and time of position
information.
3.2.4.3 Determining operator options
3.2.4.3.1 The
option to manually resend the distress alert attempt at any time should remain
available until the distress alert has been acknowledged by DSC.
3.2.4.3.2 On HF the operator should have the option to change the frequencies of
the distress alert attempt and the option to select between the single
frequency or multi frequency method.
3.2.4.3.3 The option to pause the countdown to the next distress alert attempt
should be available prior to acknowledgement by DSC.
3.2.4.3.4 The option to cancel the distress alert should be available prior to
acknowledgement by DSC.
3.2.4.3.5 The option to terminate the procedure should only be available after
acknowledgment by DSC.
3.2.4.4 The
distress alert cancel procedure
The cancel procedure consists of the cancel operation on all bands utilized
by the distress alert attempts (on VHF and MF there is only one cancel operation whereas on MF/HF there
may be up to six). The cancel operation
consists of a DSC cancel message (a self-addressed distress alert
acknowledgement) followed by a voice
cancel on the corresponding frequency of subsequent communication. The
phrase “voice cancel” refers to the
part of the cancel done over the subsequent communication frequencies whether
it is by radio telephony or on MF and MF/HF by data.
3.2.4.4.1 Upon
selection of the cancel option the sending distress automated procedure should
provide an explanation of the cancel
procedure to the operator and provide the option to either continue or
return and not do the cancel.
3.2.4.4.2 If the operator selects to proceed with the cancel procedure the sending distress automated procedure should pause
the countdown to the next automated sending of the distress alert attempt and
wait (if necessary) until any alert within an attempt is transmitted to
completion before allowing the operator to initiate the first cancel operation.
3.2.4.4.3 The operator options during the cancel procedure should be to terminate
the cancel procedure and to start the cancel
operation.
3.2.4.4.4 If the cancel procedure is
terminated before the first cancel
operation is started, the sending distress automated procedure should
resume from where it left off. However, once the cancel operation is started, the option to terminate the cancel procedure should not be available
until the cancel procedure is
completed.
3.2.4.4.5 The
status of the cancel procedure should
be displayed.
3.2.4.4.6 The
operator should be provided with the appropriate text for the voice cancel at the time of the voice cancel.
3.2.4.4.7 The cancel operation should be able to be
repeated on any band but a warning should be provided that the cancel has
already been done on this band;
3.2.4.4.8 Special
considerations for MF/HF
3.2.4.4.8.1 The
status of each of the bands should be displayed;
3.2.4.4.8.2 Once
one band is cancelled the option to end the cancel
procedure should not be available until ALL utilized bands are cancelled;
3.2.4.4.9 When
the cancel procedure is completed,
the sending distress automated procedure should be considered acknowledged and
the fact that a cancel was performed should be displayed.
3.2.4.5 MF/HF only scanning
for distress alert acknowledgements on MF/HF
The sending distress
automated procedure should scan all six distress DSC channels if not already
doing so.
3.2.5 Radio
Telephone Communications Automated Procedure
The equipment should
also be provided with a communications function for radio telephony that is
compatible with the DSC automated procedures described in this Annex. This
automated procedure should have:
3.2.5.1
the
ability to switch between being active or being on hold at the discretion of
the operator,
3.2.5.2
the
ability to be terminated at the discretion of the operator,
3.2.5.3
the
ability to select the channels for the communications, and
3.2.6Other Non-DSC Automated Procedures
Any other non DSC
functionality that is included in the equipment should
3.2.6.1 be able to be activated or placed
on hold at the discretion of the operator,
3.2.6.2 never control the watch receiver
such that DSC automated procedures, either active or on hold, are unable to
receive DSC messages on the watch receiver,
3.2.6.3 be able to be terminated by the operator.
3.3 Tasks
concerning multiple automated procedures
3.3.1 Number
of simultaneous automated procedures
Facilities should be
provided to handle a minimum of sevensix
simultaneous automated procedures including with a reserve of one. The initiation of the
reserve automated procedure should
a. warn the operator that the equipment cannot handle another automated
procedure and that one automated procedure should be terminated,
b. prevent the operator from initiating any new automated procedures
except for the sending of a distress alert and,
c. warn the operator that the reception of an additional DSC message that
would initiate an automated procedure if the equipment were in standby will
result in the automatic and immediate termination of an inactive automated
procedure where
d. the automatic and immediate termination should be based upon age and
priority.
3.3.2 Sending
distress automated procedure
When initiating a
sending distress automated procedure, automatic immediate termination of all
other automated procedures (if any) is encouraged but not required.
3.3.3 Operator
options
3.3.3.1 The operator should be able to freely navigate between the automated
procedures except when engaged in an unacknowledged sending distress automated
procedure.
3.3.3.2 When the operator makes any one of the automated procedures on hold
active, the automated procedure that was active (if any) should automatically
go on hold.
3.3.4 Unacknowledged
poll, test, or position request automated procedures received on hold
If any of these
automated procedures is set to automatically acknowledge, it should
automatically acknowledge and self terminate as soon as all remaining automated
procedures are on hold.
3.4 Warnings:
Warnings should be provided when the operator
attempts to do the following:
3.4.1 send
a relay before three minutes have elapsed since the automated procedure
started,
3.4.2 send a non individually addressed relay,
3.4.3 send a distress alert acknowledgement (requires coast station
permission),
3.4.4 send an all stations (116 format) distress relay acknowledgement (should
be sent by coast station only),
3.4.5 send an acknowledgement to a DSC message containing no distress
information that is not individually addressed,
3.4.6 cancel a distress alert,
3.4.7 send any DSC message after the objective of the automated procedure has
been obtained,
3.4.8 terminate the automated procedure before the objective has been reached,
3.4.9 terminate the automated procedure if engaged in subsequent
communications.
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