ISO INTERNATIONAL STANDARD 18427 First edition 2013-06-01 Space data and information transfer systems s Spacecraft Onboard Interface Services Subnetwork Synchronization Service Systemes de transfert des informations et données spatiales Services d'interfaces a bord des véhicules spatiaux - Service de synchronisationparsous-réseau Reference number ISO 18427:2013(E) @ISO 2013 IHSunder Not for Resale ISO 18427:2013(E) COPYRIGHTPROTECTEDDOCUMENT 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 or an intranet, without prior written permission. ISO copyright office Case postale 56:CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland @IsO2013-All rightsreserved itted without license from IHS Not for Resale ISO 18427:2013(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies technicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeen established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with 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/lEC Directives, Part 1. In particular the different approval criteria needed for the different types o 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 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 patentdeclarationsreceived.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. CCsDS 853.0-M-1, December 2009) and was adopted (without modifications 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. ili