ETSI TS 103 246-1 V1.3.1 (2020-10)

Satellite Earth Stations and Systems (SES); GNSS based location systems; Part 1: Functional requirements

RTS/SES-00451

General Information

• Status: Not Published
• Technical Committee: SES SCN - Satellite Communications and Navigation
• Current Stage: 12 - Completion
• Due Date: 10-Sep-2020
• Completion Date: 01-Oct-2020
• Mandate: M/496

Standards Content (Sample)

ETSI TS 103 246-1 V1.3.1 (2020-10)






TECHNICAL SPECIFICATION
Satellite Earth Stations and Systems (SES);
GNSS based location systems;
Part 1: Functional requirements

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2 ETSI TS 103 246-1 V1.3.1 (2020-10)



Reference
RTS/SES-00451
Keywords
functional, GNSS, location, navigation, receiver,
requirements, satellite, system, terminal
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3 ETSI TS 103 246-1 V1.3.1 (2020-10)
Contents
Intellectual Property Rights . 4
Foreword . 4
Introduction . 4
Modal verbs terminology . 5
1 Scope . 6
2 References . 6
2.1 Normative references . 6
2.2 Informative references . 6
3 Definition of terms, symbols and abbreviations . 7
3.1 Terms . 7
3.2 Symbols . 10
3.3 Abbreviations . 10
4 Context description . 11
4.1 Location based applications requirements . 11
4.1.1 Reminder of ETSI TR 103 183 content . 11
4.1.2 Common requirements . 11
4.1.3 Specific requirements . 11
4.2 Generic location-based application use case . 13
4.3 GNSS-based location systems . 15
5 Functional requirements for GNSS-based Location system. 16
5.1 Functional requirements outline . 16
5.2 Mandatory requirements . 16
5.2.1 Positioning techniques . 16
5.2.2 Location-related data delivery . 16
5.2.3 Location system policies . 17
5.3 Requirements for optional features . 17
5.3.1 Positioning techniques . 17
5.3.2 Location-related data content . 17
5.3.3 Location-related data delivery . 18
5.4 GBLS Functional requirements summary . 19
Annex A (informative): Common positioning techniques . 20
A.1 GNSS methods . 20
A.2 Assisted-GNSS methods . 20
A.3 Differential GNSS methods . 21
A.3.1 General . 21
A.3.2 D-GNSS . 22
A.3.3 RTK . 22
A.3.4 NRTK . 23
A.3.5 PPP . 24
A.4 Mixing GNSS and telecommunication positioning techniques . 25
A.4.1 Proximity sensing . 25
A.4.2 Multilateration . 25
A.4.3 Triangulation . 27
A.5 Multi-sensor positioning through GNSS or Assisted/Differential GNSS hybridization . 27
Annex B (informative): GBLS High level functional analysis . 29
History . 30

ETSI

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4 ETSI TS 103 246-1 V1.3.1 (2020-10)
Intellectual Property Rights
Essential patents
IPRs essential or potentially essential to normative deliverables may have been declared to ETSI. The information
pertaining to these essential IPRs, if any, is publicly available for ETSI members and non-members, and can be found
in ETSI SR 000 314: "Intellectual Property Rights (IPRs); Essential, or potentially Essential, IPRs notified to ETSI in
respect of ETSI standards", which is available from the ETSI Secretariat. Latest updates are available on the ETSI Web
server (https://ipr.etsi.org/).
Pursuant to the ETSI IPR Policy, no investigation, including IPR searches, has been carried out by ETSI. No guarantee
can be given as to the existence of other IPRs not referenced in ETSI SR 000 314 (or the updates on the ETSI Web
server) which are, or may be, or may become, essential to the present document.
Trademarks
The present document may include trademarks and/or tradenames which are asserted and/or registered by their owners.
ETSI claims no ownership of these except for any which are indicated as being the property of ETSI, and conveys no
right to use or reproduce any trademark and/or tradename. Mention of those trademarks in the present document does
not constitute an endorsement by ETSI of products, services or organizations associated with those trademarks.
Foreword
This Technical Specification (TS) has been produced by ETSI Technical Committee Satellite Earth Stations and
Systems (SES).
The present document is part 1 of a multi-part deliverable covering the GNSS based location systems, as identified
below:
Part 1: "Functional requirements";
Part 2: "Reference Architecture";
Part 3: "Performance requirements";
Part 4: "Requirements for location data exchange protocols";
Part 5: "Performance Test Specification".
Introduction
The increasing expansion of location-based applications aims to satisfy more and more complex and diversified user
requirements: this is highlighted for example by the widespread adoption of multi-functional smart-phones or by the
ever wider adoption of tracking devices (e.g. in transport), etc. This requirement for new and innovative location-based
applications is generating a requirement for increasingly complex location systems.
The wide spectrum of location-based applications identified in ETSI TR 103 183 [i.1] calls for a new and broader
concept for location systems, taking into account solutions in which GNSS technologies are complemented with other
technologies to improve robustness and performance. The notion of GNSS-based location systems is introduced and
defined in the present document.
Additional clauses and information related to the implementation in GNSS-based location systems of the various
differential GNSS technologies, namely D-GNSS, RTK and PPP are also included in order to facilitate the use of this
set of standards by manufacturers and service providers.
ETSI

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5 ETSI TS 103 246-1 V1.3.1 (2020-10)
Modal verbs terminology
In the present document "shall", "shall not", "should", "should not", "may", "need not", "will", "will not", "can" and
"cannot" are to be interpreted as described in clause 3.2 of the ETSI Drafting Rules (Verbal forms for the expression of
provisions).
"must" and "must not" are NOT allowed in ETSI deliverables except when used in direct citation.
ETSI

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6 ETSI TS 103 246-1 V1.3.1 (2020-10)
1 Scope
The present document defines the functional requirements applicable to location systems, based on a summary of types
of applications relying on location-related data provided by location systems.
The present document can be considered as the Stage 1 characterization of location systems according to the ITU/3GPP
approach [i.2].
ETSI TS 103 246 parts 2 [i.14], 3 [i.15], 4 [i.16] and 5 [i.17] addresse integrated GNSS based location systems (GBLS)
that combine Global Navigation Satellite Systems (GNSS), with other navigation technologies, as well as with
telecommunication networks in order to deliver location-based services to users. As a consequence the present
document is not applicable to GNSS only receivers.
ETSI TS 103 246 parts 2 [i.14], 3 [i.15], 4 [i.16] and 5 [i.17] propose a list of functional and performance requirements
and related test procedures. For each performance requirement, different classes are defined allowing the benchmark of
different GNSS Based Location Systems (GBLS) addressing the same applications. The requirements are intended to
address the growing use of complex location systems required for the provision of location-based applications
particularly for the mass-market (refer to ETSI TR 103 183 [i.1]).
2 References
2.1 Normative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
Referenced documents which are not found to be publicly available in the expected location might be found at
https://docbox.etsi.org/Reference.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are necessary for the application of the present document.
Not applicable.
2.2 Informative references
References are either specific (identified by date of publication and/or edition number or version number) or
non-specific. For specific references, only the cited version applies. For non-specific references, the latest version of the
referenced document (including any amendments) applies.
NOTE: While any hyperlinks included in this clause were valid at the time of publication, ETSI cannot guarantee
their long term validity.
The following referenced documents are not necessary for the application of the present document but they assist the
user with regard to a particular subject area.
[i.1] ETSI TR 103 183: "Satellite Earth Stations and Systems (SES); Global Navigation Satellite
Systems (GNSS) based applications and standardisation needs".
[i.2] Recommendation ITU-T I.130: "Method for the characterization of telecommunication services
supported by an ISDN and network capabilities of an ISDN".
[i.3] IS-GPS-200K: "Navstar GPS Space Segment/Navigation User Segment Interfaces".
[i.4] IS-GPS-705F: "Navstar GPS Space Segment/User Segment L5 Interfaces".
[i.5] IS-GPS-800F: "Navstar GPS Space Segment/User Segment L1C Interfaces".
ETSI

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7 ETSI TS 103 246-1 V1.3.1 (2020-10)
[i.6] "European GNSS (Galileo) Open Service: Signal In Space Interface Control Document", Issue 1.3.
[i.7] "Global Navigation Satellite System GLONASS Interface Control Document", Version 5.1.
[i.8] DTFA01-96-C-00025: "Specification for the Wide Area Augmentation System (WAAS)", US
Department of Transportation, Federal Aviation Administration.
[i.9] RTCA DO-229E: "Minimum Operational Performance Standards for Global Positioning
System/Satellite-Based Augmentation System Airborne Equipment", SBAS ICD Annex 1.
[i.10] IS-QZSS-PNT-003: "Quasi-Zenith Satellite System Interface Specification Satellite Positioning,
Navigation and Timing Service", Revision 003.
[i.11] BDS-SIS-ICD-B1I-3.0: "BeiDou Navigation Satellite System Signal In Space Interface Control
Document; Open Service Signal B1I (Version 3.0)".
[i.12] BDS-SIS-ICD-B1C-1.0: "BeiDou Navigation Satellite System Signal In Space Interface Control
Document; Open Service Signal B1C (Version 1.0)".
[i.13] ISRO-IRNSS-ICD-SPS-1.1: "Signal In Space ICD For Standard Positioning Service Version 1.1".
[i.14] ETSI TS 103 246-2: "Satellite Earth Stations and Systems (SES); GNSS based location systems;
Part 2: Reference Architecture".
[i.15] ETSI TS 103 246-3: "Satellite Earth Stations and Systems (SES); GNSS based location systems;
Part 3: Performance requirements".
[i.16] ETSI TS 103 246-4: "Satellite Earth Stations and Systems (SES); GNSS based location systems;
Part 4: Requirements for location data exchange protocols".
[i.17] ETSI TS 103 246-5: "Satellite Earth Stations and Systems (SES); GNSS based location systems;
Part 5: Performance Test Specification".
3 Definition of terms, symbols and abbreviations
3.1 Terms
For the purposes of the present document the following terms apply:
Accumulated Delta (or Doppler) Range (ADR): pseudorange-rate measurement using the carrier which measures
the instantaneous phase of the signal (modulo 1 cycle) plus some arbitrary number of integer cycles
NOTE: Once the receiver is tracking the satellite, the integer number of cycles correctly accumulates the change
in range seen by the receiver. Also see carrier phase measurement.
accuracy (or error): difference between a measured or estimated value and its real value
authentication: process/protocol to provide authenticity
authenticity: assurance that the location-related data associated with a location target has been derived from real and
not falsified signals
availability: percentage of time when a location system is able to provide the required location-related data
carrier phase measurement: measure of the range between the satellite and receiver expressed in units of cycles of the
carrier frequency
continuity: likelihood that the location system functionality will be available during the complete duration of the
intended operation if the system is operational at the beginning of the operation
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8 ETSI TS 103 246-1 V1.3.1 (2020-10)
D-GNSS: technique aiming at enhancing position accuracy and integrity of a GNSS receiver by using differential
pseudo range corrections and "do not use flag" for faulty satellites delivered by a GNSS reference station located at a
known location
NOTE: In the present document, the term D-GNSS refers to conventional differential GNSS.
electromagnetic interference: any source of RF transmission that is within the frequency band used by a
communication link, which degrades the performance of this link
fraud: any kind of activity of a location-based application stakeholder aiming at jeopardizing the application objective
GNSS-Based Location System (GBLS): location system using GNSS as the primary source of positioning
GNSS only receiver: location receiver using GNSS as the unique source of positioning
data integrity: assurance that the consistency of data is guaranteed
integrity (equivalent to "location integrity" in GBLS context): measure of the trust in the accuracy of the location-
related data provided by the location system and the ability to provide timely and valid warnings to users when the
location system does not fulfil the condition for intended operation
NOTE: Integrity is expressed through the computation of a protection level. The Integrity function is designed to
deliver a warning (or alert) of any malfunction to users within a given period of time (time-to-alert).
Related to the Integrity concept, a Loss of Integrity event occurs when an unsafe condition (i.e. a
positioning error higher than the protection level) occurs without a warning to the users for a time longer
than the time-to-alert limit.
jamming: deliberate transmission of interference in order to disrupt communications
NOTE: In the present technical context, targeted communication signals are GNSS or telecommunication signals.
latency: measure of the time elapsed between the event triggering the determination of the location-related data for a
location target and the availability of the location-related data at the user interface
location-based application: application which is able to deliver a service to one or several users, built on the
processing of the location information (location-related data) related to one or several targets
location-related data: set of data associated with a given location target, containing one or several of the following
time-tagged information elements: target position, target motion indicators (velocity and acceleration), quality of
service indicators (estimates of the position accuracy, reliability or authenticity)
location system: system responsible for providing to a location based application the location-related data of one or
several location targets
location target: physical entity (mobile or stationary) whose position is the focus of the location related data to be built
by the location system
Precise Point Positioning (PPP): differential GNSS technique that uses a worldwide distributed network of reference
stations to provide, in quasi real time, a highly accurate geodetic positioning of a receiver
privacy: function of a location system that aims at ensuring that the location target user private information (identity,
bank accounts, etc.) and its location-related data cannot be accessed by a non-authorized third party
Protection Level (PL): upper bound to the position error such that: P(ε > PL) < I , where I is the Integrity risk and
risk risk
ε is the actual position error
NOTE: The protection level is provided by the location system, and with the integrity risk, is one of the two sub-
features of the integrity system. The protection level is computed both in the vertical and in the horizontal
position domain and it is based on conservative assumptions that can be made on the properties of the
GNSS sensor measurements, i.e. the measurement error can be bounded by a statistical model and the
probability of multiple simultaneous measurement errors can be neglected.
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9 ETSI TS 103 246-1 V1.3.1 (2020-10)
pseudo range: pseudo distance between a satellite and a navigation receiver computed by multiplying the propagation
delay determined by the receiver with the speed of light
NOTE: The prefix "pseudo" highlights the fact that the propagation delay accessible to the receiver encompasses
contributions (such as receiver local clock offset with respect to satellite time) which do not allow it to
determine directly the actual geometrical distance.
Pseudo Range Correction (PRC): simple difference between a pseudo range measured by a GNSS reference station,
set at a known location and the estimated range between the satellite and this known location
NOTE 1: The estimated range generally uses the computed satellite clock bias correction and may use the estimated
receiver clock bias correction.
NOTE 2: The Pseudo Range Correction represents an estimate of the total GNSS systematic error observed on one
satellite line-of-sight, comprising ionospheric delay, tropospheric delay and orbital bias residual error. It
can be directly used in a local area around the reference station to cancel most of the systematic errors.
quality of service: set of indicators that can accompany the location target's position/motion information and is
intended to reflect the quality of the information provided by the location system
NOTE: QoS indicators can include an accuracy estimate, a protection level statistic, the integrity risk, an
authentication flag.
Real Time Kinematic (RTK): particular Differential GNSS technique that provides, in real time, highly accurate
positioning of a target based on carrier phase measurements
NOTE 1: In the RTK context, the target is called the "rover", as opposed to the stationary reference station(s). RTK
makes use of the carrier phase measurements, both in the reference station and in the rover, and this
technique allows the ambiguities affecting these accurate measurements to be resolved.
NOTE 2: If the reference station is at an accurately known location, the rover can compute its accurate geodetic (or
absolute) location. Alternatively, if the reference station's geodetic location is only roughly known, RTK
can still provide high accuracy, but only on a relative and not absolute basis.
reference receiver: receiver placed at a known and surveyed position used for differential GNSS technique
NOTE: A reference receiver is an essential component of a reference station.
reference station: station placed at a known and surveyed position aiming at determining and sharing the systematic
errors of at least one GNSS constellation
rover: target or location target, mainly used in the context of Differential GNSS/RTK
security: function of a location system that aims at ensuring that the location-related data is safeguarded against
unapproved disclosure or usage inside or outside the location system, and that it is also provided in a secure and reliable
manner that ensures it is neither lost nor corrupted
spoofing: transmission of signals intended to deceive location processing into reporting false target data
target: See location target.
terminal: target or location target, mainly used in the context of Assisted GNSS
terminal-assisted: mode in which the terminal performs only the GNSS measurements (pseudo ranges, pseudo
Doppler, etc.) and sends these measurements to a remote central facility where the position calculation takes place
NOTE: This calculation may possibly use additional measurements or data from other sources (GNSS server
assistance, differential GNSS services or non GNSS sensors etc.).
terminal-based: mode in which the terminal performs the GNSS measurements and calculates its own location
NOTE: This calculation may possibly use additional measurements or data from other sources (GNSS server
assistance, differential GNSS services or non GNSS sensors etc.)
time-to-alert: time from when an unsafe integrity condition occurs to when an alerting message reaches the user
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10 ETSI TS 103 246-1 V1.3.1 (2020-10)
3.2 Symbols
Void.
3.3 Abbreviations
For the purposes of the present document, the following abbreviations apply:
rd
3GPP 3 Generation Partnership Project
ADAS Advanced Driver Assistance Systems
ADR Accumulated Delta (or Doppler) Range
ADS-B Automatic Dependent Surveillance – Broadcast
A-SMGCS Advanced Surface Movement Guidance and Control System
ATC Air Traffic Control
CID Cell-ID
D-GNSS Differential GNSS
E-CID Enhanced Cell-ID
EGNOS European Geostationary Navigation Overlay System
E-OTD Enhanced Observed Time Difference
FKP Flachen Korrektur Parameter (German)
GAGAN GPS-Aided Geo-Augmented Navigation
GBLS GNSS-Based Location Systems
GEO Geostationary Earth Orbit
GLONASS Global Navigation Satellite System (Russian based system)
GNSS Global Navigation Satellite System
GPS Global Positioning System
GSM Global System for Mobile communications
INS Inertial Navigation Sensor
IRNSS Indian Regional Navigational Satellite System
IT Information Technology
ITS Intelligent Transport Systems
LAD-GNSS Local Area Differential GNSS
LTE Long Term Evolution
M&C Monitoring and Control
MAC Master Auxiliary Correction
MMI Man-Machine Interface
MNO Mobile Network Operator
MSAS Multi-functional Satellite Augmentation System
NRTK Network RTK
OBU On-Board Unit
OSR Observation State Representation
OTDOA Observed Time Difference Of Arrival
PAYD Pay As You Drive
PL Protection Level
PPP Precise Point Positioning
PRC Pseudo-Range Correction
PVT Position, Velocity and Time
QoS Quality of Service
QZSS Quasi-Zenith Satellite System
RF Radio Frequency
RTCA Radio Technical Commission for Aeronautics
RTK Real Time Kinematic
SBAS Satellite Based Augmentation System
SNR Signal to Noise Ratio
SSR Space State Representation
UDRE User Differential Range Errors
UHF Ultra High Frequency
UMTS Universal Mobile Telecommunications System
UTDOA Uplink Time Difference of Arrival
VHF Very High Frequency
VRS Virtual Reference Station
ETSI

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