prEN 50159
(Main)Railway Applications - Communication, signalling and processing systems - Safety-related communication in transmission systems
Railway Applications - Communication, signalling and processing systems - Safety-related communication in transmission systems
This document is applicable to safety-related electronic systems using for digital communication purposes a transmission system which was not necessarily designed for safety-related applications. For transmission systems where the risk of unauthorized access is not tolerable, the document defines the interface to the applicable cybersecurity standards. Both safety-related equipment and non-safety-related equipment can be connected to the transmission system. This document gives the specific requirements needed to achieve safety-related communication between safety-related equipment connected to the transmission system, while the general system requirements including allocation of safety requirements and content of the safety case are defined in EN 50129. This document is not applicable to existing systems, which had already been accepted prior to the release of this document. However, so far as reasonably practicable, it is applicable to modifications and extensions to existing systems, subsystems and equipment. This document does not specify – the transmission system, – equipment connected to the transmission system, – solutions (e.g. for interoperability), – which kind of data are safety-related and which are not. A safety-related equipment connected through an open transmission system can be subjected to many different IT security threats, against which an overall program is defined, encompassing management, technical and operational aspects.
Bahnanwendungen - Telekommunikationstechnik, Signaltechnik und Datenverarbeitungssysteme - Sicherheitsrelevante Kommunikation in Übertragungssystemen
Applications ferroviaires - Systèmes de signalisation, de télécommunication et de traitement - Communication de sécurité sur des systèmes de transmission
Železniške naprave - Komunikacijski, signalni in procesni sistemi - Varnostna komunikacija v prenosnih sistemih
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-marec-2025
Železniške naprave - Komunikacijski, signalni in procesni sistemi - Varnostna
komunikacija v prenosnih sistemih
Railway Applications - Communication, signalling and processing systems - Safety-
related communication in transmission systems
Bahnanwendungen - Telekommunikationstechnik, Signaltechnik und
Datenverarbeitungssysteme - Sicherheitsrelevante Kommunikation in
Übertragungssystemen
Applications ferroviaires - Systèmes de signalisation, de télécommunication et de
traitement - Communication de sécurité sur des systèmes de transmission
Ta slovenski standard je istoveten z: prEN 50159
ICS:
35.240.60 Uporabniške rešitve IT v IT applications in transport
prometu
45.020 Železniška tehnika na Railway engineering in
splošno general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD DRAFT
NORME EUROPÉENNE
EUROPÄISCHE NORM
January 2025
ICS 35.240.60; 45.020 Will supersede EN 50159:2010; EN 50159:2010/A1:2020
English Version
Railway Applications - Communication, signalling and
processing systems - Safety-related communication in
transmission systems
Applications ferroviaires - Systèmes de signalisation, de Bahnanwendungen - Telekommunikationstechnik,
télécommunication et de traitement - Communication de Signaltechnik und Datenverarbeitungssysteme -
sécurité sur des systèmes de transmission Sicherheitsrelevante Kommunikation in
Übertragungssystemen
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2025-04-11.
It has been drawn up by CLC/SC 9XA.
If this draft becomes a European Standard, CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which
stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
This draft European Standard was established by CENELEC in three official versions (English, French, German).
A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to
the CEN-CENELEC Management Centre has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Project: 79342 Ref. No. prEN 50159 E
Contents Page
13 European foreword . 3
14 Introduction . 4
15 1 Scope . 5
16 2 Normative references . 5
17 3 Terms, definitions and abbreviations . 5
18 3.1 Terms and definitions . 5
19 3.2 Abbreviations . 15
20 4 Reference architecture . 16
21 5 Hazards arising from the transmission system. 17
22 6 Classification of transmission systems . 19
23 6.1 General . 19
24 6.2 General aspects of classification . 19
25 6.3 Specific aspects for the classification of transmission systems . 19
26 6.4 Relationship between transmission systems and the basic message errors . 21
27 7 Requirements for safety defences . 21
28 7.1 Preface . 21
29 7.2 General requirements . 22
30 7.3 Specific defences . 23
31 7.4 Applicability of defences . 29
32 Annex A (informative) Hazards arising from open transmission systems . 30
33 A.1 System view . 30
34 A.2 Derivation of the basic message errors . 31
35 A.3 Network failure modes . 32
36 A.4 A possible approach for hazard identification . 33
37 A.5 Conclusions . 37
38 Annex B (informative) Categories of transmission systems . 39
39 B.1 Categories of transmission systems . 39
40 B.2 Relationship between the category of transmission systems and basic message errors . 39
41 Annex C (informative) Guideline for defences . 41
42 C.1 Applications of time stamps . 41
43 C.2 Choice and use of safety codes and cryptographic algorithms . 42
44 C.3 Safety code . 47
45 C.4 Length of safety code . 49
46 C.5 Communication between safety-related and non safety-related applications . 52
47 Bibliography . 54
49 European foreword
50 This document [prEN 50159:2025] has been preprared by CLC/SC 9XA “Communication, signalling and
51 processing systems”.
52 This document is currently submitted to the Enquiry.
53 The following dates are proposed:
• latest date by which the existence of this (doa) dav + 6 months
document has to be announced at national
level
• latest date by which this document has to be (dop) dav + 12 months
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) dav + 36 months
conflicting with this document have to be (to be confirmed or
withdrawn modified when voting)
55 This document will supersede EN 50159:2010. and all of its amendments and corrigenda (if any).
56 prEN 50159:2025 includes the following significant technical changes with respect to EN 50159:2010:
57 Introduction
58 If a safety-related electronic system involves communication of information, the transmission system then
59 forms an integral part of the safety-related system, and it is understood that the end to end communication is
60 safe in accordance with EN 50129.
61 The transmission system considered in this document, which serves the transfer of information between
62 different locations, has in general no particular preconditions to satisfy. It is from the safety point of view not
63 trusted, or not fully trusted.
64 The document is dedicated to the requirements to be taken into account for the communication of safety-
65 related information over such transmission systems.
66 Although the RAM aspects are not considered in this document, it is recommended to keep in mind that they
67 are a major aspect of the operational safety.
68 The safety requirements depend on the characteristics of the transmission system. In order to reduce the
69 complexity of the approach to demonstrate the safety of the system, transmission systems have been
70 classified into three categories:
71 – Category 1: transmission systems are closed,
72 – Category 2 and Category 3: transmission systems are open.
73 Application messages using Category 3 transmission systems need protection against unauthorised access.
74 The specific cybersecurity requirements for Category 3 transmission systems are out of the scope of this
75 document. For such systems, cybersecurity standards are applicable.
76 1 Scope
77 This document is applicable to safety-related electronic systems using for digital communication purposes a
78 transmission system which was not necessarily designed for safety-related applications. For transmission
79 systems where the risk of unauthorized access is not tolerable, the document defines the interface to the
80 applicable cybersecurity standards.
81 Both safety-related equipment and non-safety-related equipment can be connected to the transmission
82 system.
83 This document gives the specific requirements needed to achieve safety-related communication between
84 safety-related equipment connected to the transmission system, while the general system requirements
85 including allocation of safety requirements and content of the safety case are defined in EN 50129.
86 This document is not applicable to existing systems, which had already been accepted prior to the release of
87 this document. However, so far as reasonably practicable, it is applicable to modifications and extensions to
88 existing systems, subsystems and equipment.
89 This document does not specify
90 – the transmission system,
91 – equipment connected to the transmission system,
92 – solutions (e.g. for interoperability),
93 – which kind of data are safety-related and which are not.
94 A safety-related equipment connected through an open transmission system can be subjected to many
95 different IT security threats, against which an overall program is defined, encompassing management,
96 technical and operational aspects.
97 2 Normative references
98 The following documents are referred to in the text in such a way that some or all of their content constitutes
99 requirements of this document. For dated references, only the edition cited applies. For undated references,
100 the latest edition of the referenced document (including any amendments) applies.
101 EN 50129:2018, Railway applications – Communication, signalling and processing systems – Safety related
102 electronic systems for signalling
103 CLC/TS 50701:2023, Railway applications – Cybersecurity
104 IEC 63452, Rail applications - Cybersecurity
105 3 Terms, definitions and abbreviations
106 3.1 Terms and definitions
107 For the purposes of this document, the following terms and definitions apply.
108 ISO and IEC maintain terminology databases for use in standardization at the following addresses:
109 — ISO Online browsing platform: available at https://www.iso.org/obp
110 — IEC Electropedia: available at https://www.electropedia.org
As impacted by EN 5019:2018/AC:2019-04.
Under preparation.
111 3.1.1
112 absolute time stamp
113 time stamp referenced to a global time which is common for a group of entities using a transmission system
114 [SOURCE: IEV 821-11-01]
115 3.1.2
116 access control
117 protection of system resources against unauthorized access
118 Note to entry: In this document, this definition applies only to data transmission.
119 [SOURCE: CLC/TS 50701:2023, modified — Note 1 to entry added]
120 3.1.3
121 additional data
122 data which is not of any use to the ultimate user processes, but is used for control, availability, and safety
123 purpose
...
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