1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS ISO 18427:2013Space data and informationtransfer systems SpacecraftOnboard Interface Services Subnetwork SynchronizationServiceBS ISO 18427:2013 BRITISH STANDARDNational forew
2、ordThis British Standard is the UK implementation of ISO 18427:2013.The UK participation in its preparation was entrusted to TechnicalCommittee ACE/68/-/7, Space systems and operations - Space dataand information transfer systems.A list of organizations represented on this committee can beobtained o
3、n request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 80292 8ICS 49.140Compliance with a British
4、 Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 30 June 2013.Amendments issued since publicationDate Text affectedBS ISO 18427:2013Reference numberISO 18427:2013(E)ISO 2013INTERNATIONAL ST
5、ANDARD ISO18427First edition2013-06-01Space data and information transfer systems Spacecraft Onboard Interface Services Subnetwork Synchronization Service Systmes de transfert des informations et donnes spatiales Services dinterfaces bord des vhicules spatiaux Service de synchronisation par sous-rse
6、au BS ISO 18427:2013ISO 18427:2013(E) COPYRIGHT PROTECTED DOCUMENT ISO 2013 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet o
7、r an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.i
8、so.org Published in Switzerland ii ISO 2013 All rights reservedBS ISO 18427:2013ISO 18427:2013(E) ISO 2013 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Intern
9、ational Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with
10、 ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives,
11、 Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives Attention is drawn to the possibility that some of the el
12、ements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations recei
13、ved. www.iso.org/patents Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement. ISO 18427 was prepared by the Consultative Committee for Space Data Systems (CCSDS) (as CCSDS 853.0-M-1, December 2009) and was adopted (without mod
14、ifications except those stated in Clause 2 of this International Standard) by Technical Committee ISO/TC 20, Aircraft and space vehicles, Subcommittee SC 13, Space data and information transfer systems. BS ISO 18427:2013BS ISO 18427:2013INTERNATIONAL STANDARD ISO 18427:2013(E) ISO 2013 All rights re
15、served 1Space data and information transfer systems Spacecraft Onboard Interface Services Subnetwork Synchronization Service 1 Scope This International Standard is one of a family of documents specifying the SOIS-compliant services to be provided by onboard subnetworks. The purpose of this Internati
16、onal Standard is to define services and service interfaces provided by the SOIS Subnetwork Synchronisation Service. Its scope is to specify the service only and not to specify methods of providing the service over a variety of onboard data links. This International Standard conforms to the principle
17、s set out in the Spacecraft Onboard Interface Services Green Book and is intended to be applied together with it. The protocols which provide this service are to be documented for individual links, and this can be in the purview of individual missions, agencies, or CCSDS, depending on future circums
18、tances. The scope and field of application are furthermore detailed in subclause 1.2 of the enclosed CCSDS publication. 2 Requirements Requirements are the technical recommendations made in the following publication (reproduced on the following pages), which is adopted as an International Standard:
19、CCSDS 853.0-M-1, December 2009, Spacecraft Onboard Interface Services Subnetwork Synchronization Service. For the purposes of international standardization, the modifications outlined below shall apply to the specific clauses and paragraphs of publication CCSDS 853.0-M-1. Pages i to v This part is i
20、nformation which is relevant to the CCSDS publication only. 3 Revision of publication CCSDS 853.0-M-1 It has been agreed with the Consultative Committee for Space Data Systems that Subcommittee ISO/TC 20/SC 13 will be consulted in the event of any revision or amendment of publication CCSDS 853.0-M-1
21、. To this end, NASA will act as a liaison body between CCSDS and ISO. BS ISO 18427:2013ISO 18427:2013(E) 2 ISO 2013 All rights reserved(Blank page) BS ISO 18427:2013Recommendation for Space Data System Practices SPACECRAFT ONBOARD INTERFACE SERVICESSUBNETWORK SYNCHRONISATION SERVICE RECOMMENDED PRAC
22、TICE CCSDS 853.0-M-1 MAGENTA BOOK December 2009 ISO 18427:2013(E)3 ISO 2013 All rights reservedBS ISO 18427:2013AUTHORITY Issue: Recommended Practice, Issue 1 Date: December 2009 Location: Washington, DC, USA This document has been approved for publication by the Management Council of the Consultati
23、ve Committee for Space Data Systems (CCSDS) and represents the consensus technical agreement of the participating CCSDS Member Agencies. The procedure for review and authorization of CCSDS documents is detailed in the Procedures Manual for the Consultative Committee for Space Data Systems, and the r
24、ecord of Agency participation in the authorization of this document can be obtained from the CCSDS Secretariat at the address below. This document is published and maintained by: CCSDS Secretariat Space Communications and Navigation Office, 7L70 Space Operations Mission Directorate NASA Headquarters
25、 Washington, DC 20546-0001, USA ISO 18427:2013(E)4 ISO 2013 All rights reservedBS ISO 18427:2013CCSDS RECOMMENDED PRACTICE FOR SOIS SUBNETWORK SYNCHRONISATION SERVICE STATEMENT OF INTENT The Consultative Committee for Space Data Systems (CCSDS) is an organization officially established by the manage
26、ment of its members. The Committee meets periodically to address data systems problems that are common to all participants, and to formulate sound technical solutions to these problems. Inasmuch as participation in the CCSDS is completely voluntary, the results of Committee actions are termed Recomm
27、endations and are not in themselves considered binding on any Agency. CCSDS Recommendations take two forms: Recommended Standards that are prescriptive and are the formal vehicles by which CCSDS Agencies create the standards that specify how elements of their space mission support infrastructure sha
28、ll operate and interoperate with others; and Recommended Practices that are more descriptive in nature and are intended to provide general guidance about how to approach a particular problem associated with space mission support. This Recommended Practice is issued by, and represents the consensus o
29、f, the CCSDS members. Endorsement of this Recommended Practice is entirely voluntary and does not imply a commitment by any Agency or organization to implement its recommendations in a prescriptive sense. No later than five years from its date of issuance, this Recommended Practice will be reviewed
30、by the CCSDS to determine whether it should: (1) remain in effect without change; (2) be changed to reflect the impact of new technologies, new requirements, or new directions; or (3) be retired or cancelled. In those instances when a new version of a Recommended Practice is issued, existing CCSDS-r
31、elated member Practices and implementations are not negated or deemed to be non-CCSDS compatible. It is the responsibility of each member to determine when such Practices or implementations are to be modified. Each member is, however, strongly encouraged to direct planning for its new Practices and
32、implementations towards the later version of the Recommended Practice. CCSDS 853.0-M-1 Page ii December 2009 ISO 18427:2013(E)5 ISO 2013 All rights reservedBS ISO 18427:2013FOREWORD This document is a technical Recommended Practice for use in developing flight and ground systems for space missions a
33、nd has been prepared by the Consultative Committee for Space Data Systems (CCSDS). The Subnetwork Synchronisation Service described herein is intended for missions that are cross-supported between Agencies of the CCSDS, in the framework of the Spacecraft Onboard Interface Services (SOIS) CCSDS area.
34、 This Recommended Practice specifies a service to be used by space missions to synchronise subnetwork users to subnetwork-maintained time or asynchronous subnetwork events. The SOIS Synchronisation Service is provided by data link-specific mechanisms within the subnetwork layers. The service interfa
35、ce is present only in the data system invoking the service. The SOIS Subnetwork Synchronisation Service provides a common service interface regardless of the particular type of data link being used for communication. Through the process of normal evolution, it is expected that expansion, deletion, o
36、r modification of this document may occur. This Recommended Practice is therefore subject to CCSDS document management and change control procedures, which are defined in the Procedures Manual for the Consultative Committee for Space Data Systems. Current versions of CCSDS documents are maintained a
37、t the CCSDS Web site: http:/www.ccsds.org/ Questions relating to the contents or status of this document should be addressed to the CCSDS Secretariat at the address indicated on page i. ISO 18427:2013(E)6 ISO 2013 All rights reservedBS ISO 18427:2013CCSDS RECOMMENDED PRACTICE FOR SOIS SUBNETWORK SYN
38、CHRONISATION SERVICE At time of publication, the active Member and Observer Agencies of the CCSDS were: Member Agencies Agenzia Spaziale Italiana (ASI)/Italy. British National Space Centre (BNSC)/United Kingdom. Canadian Space Agency (CSA)/Canada. Centre National dEtudes Spatiales (CNES)/France. Chi
39、na National Space Administration (CNSA)/Peoples Republic of China. Deutsches Zentrum fr Luft- und Raumfahrt e.V. (DLR)/Germany. European Space Agency (ESA)/Europe. Russian Federal Space Agency (RFSA)/Russian Federation. Instituto Nacional de Pesquisas Espaciais (INPE)/Brazil. Japan Aerospace Explora
40、tion Agency (JAXA)/Japan. National Aeronautics and Space Administration (NASA)/USA. Observer Agencies Austrian Space Agency (ASA)/Austria. Belgian Federal Science Policy Office (BFSPO)/Belgium. Central Research Institute of Machine Building (TsNIIMash)/Russian Federation. Centro Tecnico Aeroespacial
41、 (CTA)/Brazil. Chinese Academy of Sciences (CAS)/China. Chinese Academy of Space Technology (CAST)/China. Commonwealth Scientific and Industrial Research Organization (CSIRO)/Australia. CSIR Satellite Applications Centre (CSIR)/Republic of South Africa. Danish National Space Center (DNSC)/Denmark. E
42、uropean Organization for the Exploitation of Meteorological Satellites (EUMETSAT)/Europe. European Telecommunications Satellite Organization (EUTELSAT)/Europe. Geo-Informatics and Space Technology Development Agency (GISTDA)/Thailand. Hellenic National Space Committee (HNSC)/Greece. Indian Space Res
43、earch Organization (ISRO)/India. Institute of Space Research (IKI)/Russian Federation. KFKI Research Institute for Particle section 2, describing general concepts and assumptions; section 3, containing the Subnetwork Synchronisation Service specification; section 4, containing the Management Informa
44、tion Base (MIB) for the service; section 5, comprising a Service Conformance Statement Proforma. In addition, annex A contains informative references. ISO 18427:2013(E)10 ISO 2013 All rights reservedBS ISO 18427:2013CCSDS RECOMMENDED PRACTICE FOR SOIS SUBNETWORK SYNCHRONISATION SERVICE 1.5 CONVENTIO
45、NS AND DEFINITIONS 1.5.1 BIT NUMBERING CONVENTION AND NOMENCLATURE In this document, the following convention is used to identify each bit in an N-bit field. The first bit in the field to be transmitted (i.e., the most left justified when drawing a figure) is defined to be Bit 0; the following bit i
46、s defined to be Bit 1 and so on up to Bit N1. When the field is used to express a binary value (such as a counter), the Most Significant Bit (MSB) shall be the first transmitted bit of the field, i.e., Bit 0 (see figure 1-1). BIT 0 BIT N1N-BIT DATA FIELDFIRST BIT TRANSFERRED = MSBFigure 1-1: Bit Num
47、bering Convention In accordanc with modern data communications practice, spacecraft data fields are often grouped into eight-bit words widely known as bytes. Throughout this Recommended Practice, such an eight-bit word is called an octet. The numbering for octets within a data structure starts with
48、zero. By CCSDS convention, any spare bits are permanently set to 0. 1.5.2 DEFINITIONS 1.5.2.1 General For the purpose of this document the following definitions apply. 1.5.2.2 Definitions from the Open Systems Interconnection (OSI) Basic Reference Model This document is defined using the style estab
49、lished by the Open Systems Interconnection (OSI) Basic Reference Model (reference A3). This model provides a common framework for the development of standards in the field of systems interconnection. The following terms, used in this Recommended Practice, are adapted from definitions given in reference A3: layer: subdivision of the architecture, constituted by subsystems of the same rank. CCSDS 853.0-M-1 Page 1-2 December 2009 ISO 18427:201
