IEC 61108-5:2020

IEC 61108-5 ®
Edition 1.0 2020-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Maritime navigation and radiocommunication equipment and systems –
Global navigation satellite systems (GNSS) –
Part 5: BeiDou navigation satellite system (BDS) – Receiver equipment –
Performance requirements, methods of testing and required test results

Matériels et systèmes de navigation et de radiocommunication maritimes –
Système mondial de navigation par satellite (GNSS) –
Partie 5: Système de navigation par satellite BeiDou (BDS) –
Matériels de réception – Exigences de performances, méthodes d'essai et
résultats d'essai exigés
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IEC 61108-5 ®
Edition 1.0 2020-03
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
Maritime navigation and radiocommunication equipment and systems –

Global navigation satellite systems (GNSS) –

Part 5: BeiDou navigation satellite system (BDS) – Receiver equipment –

Performance requirements, methods of testing and required test results

Matériels et systèmes de navigation et de radiocommunication maritimes –

Système mondial de navigation par satellite (GNSS) –

Partie 5: Système de navigation par satellite BeiDou (BDS) –

Matériels de réception – Exigences de performances, méthodes d'essai et

résultats d'essai exigés
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 47.020.70 ISBN 978-2-8322-7909-0

– 2 – IEC 61108-5:2020 © IEC 2020
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms, definitions and abbreviated terms . 7
3.1 Terms and definitions . 7
3.2 Abbreviated terms . 8
4 Minimum performance requirements . 9
4.1 Object . 9
4.2 BDS receiver equipment . 9
4.2.1 Minimum facilities . 9
4.2.2 Configuration . 9
4.2.3 Quality assurance . 10
4.3 Performance of BDS receiver equipment . 10
4.3.1 General . 10
4.3.2 Equipment interfaces . 10
4.3.3 Accuracy . 12
4.3.4 Acquisition . 12
4.3.5 Protection . 13
4.3.6 Antenna design . 13
4.3.7 Sensitivity and dynamic range . 13
4.3.8 Effects of specific interfering signals . 13
4.3.9 Position update . 14
4.3.10 Differential BDS input . 14
4.3.11 Navigation warnings and status indications . 15
4.3.12 Output of COG, SOG and UTC . 17
4.3.13 Typical interference conditions . 18
5 Methods of testing and required test results . 18
5.1 Test sites . 18
5.2 Test sequence . 19
5.3 Standard test signals . 19
5.4 Determination of accuracy . 19
5.5 General requirements and presentation requirements . 20
5.5.1 Normal environmental conditions for tests . 20
5.5.2 General requirements . 20
5.5.3 Presentation requirements . 20
5.6 Receiver performance tests . 20
5.6.1 BDS receiver equipment . 20
5.6.2 Position output. 20
5.6.3 Equipment interfaces . 20
5.6.4 Accuracy . 20
5.6.5 Acquisition . 22
5.6.6 Protection . 23
5.6.7 Antenna design . 23
5.6.8 Sensitivity and dynamic range . 23
5.6.9 Protection from other shipborne transmitters . 23
5.6.10 Position update . 24
5.6.11 Differential BDS input . 24

5.6.12 Navigational warnings and status indications . 25
5.6.13 Accuracy of COG and SOG. 27
5.6.14 Validity of COG and SOG information . 28
5.6.15 Output of UTC . 28
5.7 Tests for typical RF interference conditions. 28
5.7.1 Simulator conditions . 28
5.7.2 Navigation solution accuracy test . 28
5.7.3 Re-acquisition test . 29
Annex A (normative) Typical BDS interference environment. 31
A.1 BDS CW in-band and near-band interference environment . 31
A.2 Band-limited noise-like interference . 32
A.3 Pulsed interference . 33
A.4 BDS minimum antenna gain . 34
Annex B (normative) Alert management . 35
Annex C (normative) Sentences to support BDS receiver operation . 36
C.1 General . 36
C.2 DTM – Datum reference . 36
C.3 GBS – GNSS satellite fault detection . 37
C.4 GDC – GNSS differential correction . 39
C.5 GFA – GNSS fix accuracy and integrity . 41
C.6 GNS – GNSS fix data . 42
C.7 GRS – GNSS range residuals . 45
C.8 GSA – GNSS DOP and active satellites . 47
C.9 GST – GNSS pseudorange error statistics . 49
C.10 GSV – GNSS satellites in view . 50
Bibliography . 53

Figure 1 – Logical interfaces of BDS receiver . 11
Figure A.1 – CW interference thresholds for BDS receivers in steady-state navigation . 32
Figure A.2 – Interference thresholds versus bandwidth for BDS . 33

Table 1 – Acquisition time limits . 13
Table 2 – RAIM integrity states . 17
Table 3 – Accuracy of COG . 18
Table 4 – RF interference value . 29
Table A.1 – CW interference thresholds for BDS receivers in steady-state navigation . 31
Table A.2 – Interference threshold for band-limited noise-like interference to BDS

receivers in steady-state navigation . 33
Table A.3 – Interference characteristics for pulsed interference . 34
Table A.4 – BDS minimum antenna gain . 34
Table B.1 – Required alerts and their classification . 35

– 4 – IEC 61108-5:2020 © IEC 2020
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
MARITIME NAVIGATION AND RADIOCOMMUNICATION EQUIPMENT AND
SYSTEMS – GLOBAL NAVIGATION SATELLITE SYSTEMS (GNSS) –

Part 5: BeiDou navigation satellite system (BDS) – Receiver equipment –
Performance requirements, methods of testing and required test results

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61108-5 has been prepared by IEC technical committee 80:
Maritime navigation and radiocommunication equipment and systems.
The text of this International Standard is based on the following documents:
FDIS Report on voting
80/952/FDIS 80/955/RVD
Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

All text of this document, whose meaning is identical to that in IMO resolution MSC.379(93), is
printed in italics and the resolution and paragraph numbers are indicated in brackets, i.e.
(M.379/A1.2).
A list of all parts in the IEC 61108 series, published under the general title Maritime navigation
and radiocommunication equipment and systems – Global navigation satellite systems (GNSS),
can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

– 6 – IEC 61108-5:2020 © IEC 2020
MARITIME NAVIGATION AND RADIOCOMMUNICATION EQUIPMENT AND
SYSTEMS – GLOBAL NAVIGATION SATELLITE SYSTEMS (GNSS) –

Part 5: BeiDou navigation satellite system (BDS) – Receiver equipment –
Performance requirements, methods of testing and required test results

1 Scope
This part of IEC 61108 specifies the minimum performance requirements, methods of testing
and required test results for BDS shipborne receiver equipment, based on IMO resolution
MSC.379(93), which uses the signals from the BeiDou navigation satellite system in order to
determine position. It takes account of the general requirements given in IMO resolution
A.694(17) and is associated with IEC 60945. When a requirement in this document is different
from IEC 60945, the requirement in this document takes precedence. This document also takes
account, as appropriate, of requirements for the presentation of navigation-related information
on shipborne navigational displays given in IMO resolution MSC.191(79) and is associated with
IEC 62288 and MSC.302(87) associated with IEC 62923-1.
This receiver standard applies to navigation in the ocean, coastal, harbour entrances, harbour
approaches and restricted waters, as defined in IMO resolution A.915(22) and IMO resolution
A.1046(27).
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60721-3-6:1987, Classification of environmental conditions. Part 3: Classification of groups
of environmental parameters and their severities. Ship environment
IEC 60945, Maritime navigation and radiocommunication equipment and systems – General
requirements – Methods of testing and required test results
IEC 61108-4, Maritime navigation and radiocommunication equipment and systems – Global
navigation satellite systems (GNSS) – Part 4: Shipborne DGPS and DGLONASS maritime radio
beacon receiver equipment – Performance requirements, methods of testing and required test
results
IEC 61162-1, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 1: Single talker and multiple listeners
IEC 61162-2, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 2: Single talker and multiple listeners, high-speed transmission
IEC 61162-450, Maritime navigation and radiocommunication equipment and systems – Digital
interfaces – Part 450: Multiple talkers and multiple listeners – Ethernet interconnection
IEC 62288, Maritime navigation and radiocommunication equipment and systems –
Presentation of navigation-related information on shipborne navigational displays – General
requirements, methods of testing and required test results

IEC 62923-1, Maritime navigation and radiocommunication equipment and systems – Bridge
alert management – Part 1: Operational and performance requirements, methods of testing and
required test results
IEC 62923-2, Maritime navigation and radiocommunication equipment and systems – Bridge
alert management – Part 2: Alert and cluster identifiers and other additional features
ITU-R Recommendation M.823-3, Technical characteristics of differential transmissions for
global navigation satellite systems from maritime radio beacons in the frequency band 283.5-
315 kHz in Region 1 and 285-325 kHz in Regions 2 and 3
IMO resolution A.694(17), General requirements for shipborne radio equipment forming part of
the Global maritime distress and safety system (GMDSS) and for electronic navigational aids
IMO resolution A.915(22), Revised maritime policy and requirements for a future Global
Navigation Satellite System (GNSS)
IMO resolution A.1046(27), Worldwide radionavigation system
IMO resolution MSC.379(93), Performance standards for shipborne BeiDou satellite navigation
system (BDS) receiver equipment
IMO resolution MSC.401(95), Performance standards for multi-system shipborne
radionavigation receivers
RTCM 10402.4, Recommended standards for differential GNSS (Global Navigation Satellite
Systems) service
BDS-SIS-ICD-B1I-3.0, BeiDou Navigation Satellite System Signal In Space Interface Control
Document Open Service Signal B1I (Version 3.0), China Satellite Navigation Office
3 Terms, definitions and abbreviated terms
For the purposes of this document, the following terms, definitions and abbreviated terms apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Terms and definitions
3.1.1
BeiDou coordinate system
BDCS
coordinate system adopted by BDS
Note 1 to entry: The definition of BDCS is in accordance with the specifications of the International earth rotation
and reference system service (IERS), and it is consistent with the definition of the China geodetic coordinate system
2000 (CGCS2000). BDCS and CGCS2000 have the same ellipsoid parameters. The origin is located at the Earth’s
centre of mass. The Z-axis is the direction of the IERS reference pole (IRP). The X-axis is the intersection of the
IERS Reference Meridian (IRM) and the plane passing through the origin and normal to the Z-axis. The Y-axis,
together with Z-axis and X-axis, constitutes a right-handed orthogonal coordinate system. The length unit is the
international system of units (SI) metre.
Note 2 to entry: This note applies to the French language only.

– 8 – IEC 61108-5:2020 © IEC 2020
3.1.2
BDS time
BDT
time reference which adopts the international system of units (SI) second as the base unit, and
accumulates continuously without leap seconds
Note 1 to entry: The start epoch of BDT is 00:00:00 on January 1, 2006 of coordinated universal time (UTC). BDT
connects with UTC via UTC (NTSC), and the deviation of BDT to UTC is maintained within 50 ns (modulo 1 s). The
leap second information is broadcast in the navigation message.
Note 2 to entry: This note applies to the French language only.
3.1.3
BeiDou navigation satellite system
BDS
system independently developed and operated by China and providing position, velocity and
time information for users, including open service and authorized service and short messages
service
3.2 Abbreviated terms
BAM bridge alert management
CAM central alert management
COG course over ground
CW continuous wave
DBDS differential BDS
EUT equipment under test
GNSS global navigation satellite system
GPS global positioning system
HAL horizontal alert limit
HDOP horizontal dilution of precision
HPL horizontal protection limit
INS integrated navigation system
MKD minimum keyboard display
NB narrow band
NTSC National time service centre (Chinese academy of sciences)
OS open service
PDOP position dilution of precision
PNT position, navigation and timing
PVT position, velocity and time
RAIM receiver autonomous integrity monitoring
RF radio frequency
RFCS radio frequency constellation simulator
RFI radio frequency interference
SIS signal in space
SOG speed over ground
UDRE user differential range error
UTC universal time coordinated
WB wide band
4 Minimum performance requirements
4.1 Object
(M.379/A1.2) The BDS Open Service (OS) provides positioning, navigation and timing services,
free of direct user charges. The BDS receiver equipment shall be capable of receiving and
processing the open service signal.
(M.379/A1.3) BDS receiver equipment intended for navigational purposes on ships with a speed
not exceeding 70 knots, in addition to the general requirements specified in resolution A.694 (17)
and the related standard IEC 60945, shall comply with the following minimum performance
requirements.
(M.379/A1.4) The standards cover the basic requirements of position fixing, determination of
course over ground (COG), speed over ground (SOG) and timing, either for navigation purposes
or as input to other functions. The standards do not cover other computational facilities which
may be in the equipment nor cover the requirements for other systems that may take input from
the BDS receiver.
4.2 BDS receiver equipment
(See 5.6.1)
4.2.1 Minimum facilities
(M.379/A2.1) The term "BDS receiver equipment" as used in the performance standards
includes all the components and units necessary for the system to properly perform its intended
functions. The BDS receiver equipment shall include the following minimum facilities:
1) antenna capable of receiving BDS signals;
2) BDS receiver and processor;
3) means of accessing the computed latitude/longitude position;
4) data control and interface; and
5) position display and, if required, other forms of output.
If BDS forms part of an approved Integrated Navigation System (INS), requirements of facilities
3) 4) and 5) may be provided within the INS.
If BDS forms part of an approved multi-system PNT, requirements of facilities 3) 4) and 5) may
be provided within the multi-system PNT.
Other computational activity, input/output activity or extra display functions which may be
provided shall not degrade the performance of the equipment below the minimum performance
requirements set out in this document.
4.2.2 Configuration
The BDS receiver equipment may be supplied in one of several configurations to provide the
necessary position information. Examples are as follows:
– stand-alone receiver with means of accessing computed position via a keyboard with the
positional information suitably displayed;
– BDS black box receiver fed with operational parameters from external devices/remote
locations and feeding an integrated system with means of access to the computed position
via an appropriate interface, and the positional information available to at least one remote
location. With this option, a separate user interface called as MKD shall be provided as a
backup.
– 10 – IEC 61108-5:2020 © IEC 2020
– as one of PVT methods included in a multi-system PNT equipment based on IMO resolution
MSC.401(95).
The above examples should not be implied as limiting the scope of future development.
4.2.3 Quality assurance
The equipment shall be designed, produced and documented by manufacturers complying with
approved quality systems as applicable.
4.3 Performance of BDS receiver equipment
4.3.1 General
(See 5.6.2)
(M.379/A3.1) The BDS receiver equipment shall be capable of receiving and processing the
BDS positioning and velocity, and timing signals, and shall use the ionospheric model broadcast
to the receiver by the constellation to generate ionospheric corrections.
A detailed description of the BDS navigation signal characteristics is given in BDS SIS Interface
Control Document.
(M.379/A3.2) The BDS receiver equipment shall provide position information in latitude and
longitude in degrees, minutes and thousandths of minutes.
Means may be provided to transform the computed position based upon the BeiDou coordinate
system (BDCS) into data compatible with the datum of the navigational chart in use. Where this
facility exists, the display shall indicate that co-ordinate conversion is being performed and shall
identify the co-ordinate system in which the position is expressed.
NOTE BDCS is adopted by BDS and differs from WGS 84 by less than 5 cm worldwide. Conversion to WGS 84 is
not needed for maritime navigation.
(M.379/A3.3) The BDS receiver equipment shall provide time referenced to universal time
coordinated UTC (NTSC).
4.3.2 Equipment interfaces
(See 5.6.3)
(M.379/A3.4) The BDS receiver equipment shall be provided with at least two outputs from
which position information, UTC, course over ground (COG), speed over ground (SOG) and
alarms can be supplied to other equipment. The output of position information shall be based
on the WGS 84 datum and shall be in accordance with international standards. The output of
UTC, course over ground (COG), speed over ground (SOG) and alarms shall be consistent with
the requirements of M.379/A3.15 and M.379/A3.17.
(M.379/A3.16) The BDS receiver equipment shall provide at least one normally closed contact,
which shall indicate failure of the BDS receiver equipment.
(M.379/A3.17) The BDS receiver equipment shall have a bidirectional interface to facilitate
communication so that alarms can be transferred to external systems and so that audible alarms
from the BDS receiver can be acknowledged from external systems; the interface shall comply
with relevant international standards.
Sentences shall be based on IEC 61162-1. The physical interface shall be based on
IEC 61162-1 or IEC 61162-2 or IEC 61162-450.

Logical interfaces for the BDS receiver are shown in Figure 1, where required interfaces are
indicated with solid lines and optional interfaces are indicated in dashed lines.

Figure 1 – Logical interfaces of BDS receiver
BDS receiver shall use talker ID "GB".
For positioning reporting purposes, the following sentences shall be available for output in any
combination.
• DTM – Datum reference (see Annex C)
• GBS – GNSS satellite fault detection (see Annex C)
• GFA – GNSS fix accuracy and integrity (see Annex C)
• GNS – GNSS fix data (see Annex C)
• RMC – Recommended minimum specific GNSS data
• VTG – Course over ground and ground speed
• ZDA – Time and date
If a sentence uses a datum other than WGS 84, then the DTM sentence shall be used in
compliance with IEC 61162-1.
For reporting GNSS differential correction data the following sentence shall be available:
• GDC – GNSS differential correction (see Annex C)
For alert reporting and alert command purposes, the following sentences shall be available.
• ACN – Alert command
• ALC – Cyclic alert list
• ALF – Alert sentence
• ARC – Alert command refused
• HBT – Heartbeat supervision sentence
In addition, for integrating with other navigational aids, the following sentences may be available
for output in any combination.
• GRS – GNSS range residuals (see Annex C)
• GSA – GNSS DOP and active satellites (see Annex C)
• GST – GNSS pseudorange error statistics (see Annex C)
• GSV – GNSS satellites in view (see Annex C)
GBS, GRS, GSA, GST and GSV are required to support external integrity checking. They are
synchronized with corresponding fix data (GNS).

– 12 – IEC 61108-5:2020 © IEC 2020
4.3.3 Accuracy
(See 5.6.4)
4.3.3.1 Static position accuracy
(M.379/A3.5) The BDS receiver equipment shall have static accuracy such that the position of
the antenna is determined to be within 25 m horizontally (95 %) and 30 m vertically (95 %).
NOTE The BDS receiver equipment typically has accuracy better than 10 m (95 %).
4.3.3.2 Dynamic position accuracy
(M.379/A3.6) The BDS receiver equipment shall have dynamic accuracy equivalent to the static
accuracy specified in 4.3.3.1 above under the normal sea states and motion experienced in
ships.
4.3.4 Acquisition
(See 5.6.5)
(M.379/A3.8) The BDS receiver equipment shall be capable of selecting automatically the
appropriate satellite-transmitted signals to determine the ship’s position and velocity, and time
with the required accuracy and update rate.
(M.379/A3.11) The BDS receiver equipment shall be capable of acquiring position, velocity and
time to the required accuracy within 12 min where there is no valid almanac data.
(M.379/A3.12) The BDS receiver equipment shall be capable of acquiring position, velocity and
time to the required accuracy within 1 min where there is valid almanac data.
(M.379/A3.13) The BDS receiver equipment shall be capable of reacquiring position, velocity
and time to the required accuracy within 1 min when there has been a service interruption of
60 s or less.
(M.401/A3.7) The BDS receiver equipment shall be capable of providing the PVT solution to the
required accuracy within:
– 5 min where there is no valid satellite almanac data (cold start);
– 1 min where there is valid satellite almanac data (warm start); and
– 2 min, when subjected to a power interruption or loss of signals of < 60 s;
Acquisition is defined as the processing of BDS satellite signals to obtain a position fix within
the required accuracies.
Three conditions of the BDS receiver equipment are set out under which the minimum
performance requirements shall be met.
Condition A
Initialization (cold start) – The equipment has no valid almanac because it has:
– been transported over large distances (> 1 000 km to < 10 000 km) without power or BDS
signals or by the deletion of the current almanac; or
– not been powered for > 7 days; or
– not received BDS signals for > 7 days.

Condition B
Warm start – The equipment has a valid almanac.
– Power outage – the equipment under normal operation loses power for at least 24 h; or
– Interruption of BDS signals – under normal operation the BDS signals receptions are
interrupted for at least 24 h, but there is no loss of power.
Condition C
Brief interruption of power or BDS signals – under normal operation, the power or the signals
are interrupted for 60 s.
No user action other than applying power and providing a clear view from the antenna for the
BDS signals shall be necessary, from any of the initial conditions above, in order to achieve the
required acquisition time limits in Table 1.
Table 1 – Acquisition time limits
Equipment condition A B C
Acquisition time limits (min) 5 1 2

4.3.5 Protection
(See 5.6.6)
(M.379/A5) Precautions shall be taken to ensure that no permanent damage can result from an
accidental short circuit or grounding of the antenna or any of its input or output connections or
any of the BDS receiver equipment inputs or outputs for a duration of five minutes.
4.3.6 Antenna design
(See 5.6.7)
(M.379/A2.2) The antenna design shall be suitable for fitting at a position on the ship which
ensures a clear view of the satellite constellation, taking into consideration any obstructions
that might exist on the ship.
4.3.7 Sensitivity and dynamic range
(See 5.6.8）
(M.379/A3.9) The BDS receiver equipment shall be capable of acquiring satellite signals with
input signals having carrier levels in the range of –130 dBm to –120 dBm. Once the satellite
signals have been acquired, the equipment shall continue to operate satisfactorily with satellite
signals having carrier levels down to –133 dBm.
4.3.8 Effects of specific interfering signals
(See 5.6.9)
The BDS receiver equipment shall meet the following requirements.
a) In a normal operating mode, i.e. switched on and with antenna attached, it is subject to
radiation of 3 W/m at a frequency of 1 636,5 MHz for 10 min. When the unwanted signal is
removed and the BDS receiver antenna is exposed to the normal BDS satellite signals, the
BDS receiver equipment shall calculate valid position fixes within 5 min without further
operator intervention.
– 14 – IEC 61108-5:2020 © IEC 2020
NOTE 1 This is equivalent to exposing a BDS antenna to radiation from an Inmarsat Fleet 77 antenna at 10 m
distance along the bore sight. This requirement will not be valid after Inmarsat Fleet 77 is closed.
b) In a normal operating mode, i.e. switched on, and with antenna attached, it is subject to
radiation consisting of a burst of 10 pulses, each 1,0 µs to 1,5 µs long on a duty cycle of
1 600:1 at a frequency lying between 2,9 GHz and 3,1 GHz at power density of about
7,5 kW/m . The condition shall be maintained for 10 min with the bursts of pulses repeated
every 3 s. When the unwanted signal is removed and the BDS receiver antenna is exposed
to the normal BDS satellite signals, the receiver shall calculate valid position fixes within
5 min without further operator intervention.
NOTE 2 This condition is approximately equivalent to exposing the antenna to radiation from a 60 kW "S" Band
marine radar operating at a nominal 1,2 µs pulse width at 600 pulses/s using a 4 m slot antenna rotating at
20 r/min with the BDS antenna placed in the plane of the bore site of the radar antenna at a distance of 10 m
from the centre of rotation.
c) In a normal operating mode, i.e. switched on and with antenna attached, it is subject to
radiation of 0,16 W/m at a frequency in the range of 1 626,5 MHz to 1 660,5 MHz for 10 min.
During the period, the BDS receiver equipment shall be able to calculate valid position fixes.
NOTE 3 This is equivalent to exposing a BDS antenna to radiation from an Inmarsat FleetBroadband antenna
at 10 m distance along the bore sight.
Advice shall be given in the manual for adequate installation of the antenna unit, to minimize
interference with other radio equipment such as marine radars, Inmarsat ship earth stations,
Iridium ship earth stations, etc.
NOTE 4 Given that Iridium GMDSS ship earth stations and BDS receivers operate in adjacent and shared spectrum,
the installation manual can include relevant antenna installation warnings and guidelines, including the amount of
separation from Iridium ship earth station antennas and other factors necessary to avoid radio frequency interference.
4.3.9 Position update
(See 5.6.10)
(M.379/A3.14) The BDS receiver equipment shall generate and output to a display and digital
interface (conforming to IEC 61162-1) a new position solution at least once every 1 s for
conventional craft and at least once every 0,5 s for high speed craft.
For high speed craft purposes, the equipment shall additionally provide an IEC 61162-2 or
IEC 61162-450 interface with a position update rate of 2 Hz.
(M.379/A3.7) The BDS receiver equipment shall have position resolution equal to or better than
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