ISO 22672:2011

INTERNATIONAL ISO
STANDARD 22672
Second edition
2011-11-15
Space data and information transfer
systems — Space link extension (SLE) —
Forward space packet service
specification
Systèmes de transfert des informations et données spatiales —
Extension de liaisons spatiales (SLE) — Spécification d'envoi de
données spatiales par paquets
Reference number
©
ISO 2011
©  ISO 2011
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ii © ISO 2011 – All rights reserved

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International 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 ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 22672 was prepared by the Consultative Committee for Space Data Systems (CCSDS) as
CCSDS 912.3-B-2, July 2010 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.
This second edition cancels and replaces the first edition (ISO 22672:2006), which has been technically
revised.
INTERNATIONAL STANDARD ISO 22672:2011(E)

Space data and information transfer systems — Space link
extension (SLE) — Forward space packet service specification
1 Scope
1.1 This International Standard defines the Forward Space Packet (FSP) service in conformance with the
transfer services specified in CCSDS 910.4-B-2 (equivalent to ISO 15396). The FSP service is a Space Link
Extension (SLE) transfer service that enables a mission to send Space Packets to a spacecraft in sequence-
controlled or expedited mode.
1.2 This International Standard defines, in an abstract manner, the FSP service in terms of
a) the operations necessary to provide the transfer service,
b) the parameter data associated with each operation,
c) the behaviors that result from the invocation of each operation, and
d) the relationship between, and the valid sequence of, the operations and resulting behaviors.
1.3 It does not specify
a) individual implementations or products,
b) the implementation of entities or interfaces within real systems,
c) the methods or technologies required to radiate Space Packets to a spacecraft and to acquire telemetry
frames from the signals received from that spacecraft for extraction of the Operational Control Field,
d) the methods or technologies required for communications, or
e) the management activities necessary to schedule, configure, and control the FSP service.
1.4 The scope and field of application are furthermore detailed in subclauses 1.2 and 1.3 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:
CCSDS 912.3-B-2, July 2010, Space link extension — Forward space packet service specification.
For the purposes of international standardization, the modifications outlined below shall apply to the specific
clauses and paragraphs of publication CCSDS 912.3-B-2.
Pages i to vi
This part is information which is relevant to the CCSDS publication only.
Page 1-14
Add the following information to the reference indicated:
[1] Document CCSDS 910.4-B-2, October 2005, is equivalent to ISO 15396:2007.
[2] Document CCSDS 301.0-B-3, January 2002, is equivalent to ISO 11104:2003.
[3] Document CCSDS 231.0-B-1, September 2003, is equivalent to ISO 22642:2005.
[4] Document CCSDS 232.0-B-1, September 2003, is equivalent to ISO 22664:2005.
[5] Document CCSDS 232.1-B-1, September 2003, is equivalent to ISO 22667:2005.
[6] Document CCSDS 133.0-B-1, September 2003, is equivalent to ISO 22646:2005.
[7] ISO/IEC 8824-1:2002 has been cancelled and withdrawn. It has been replaced by
ISO/IEC 8824-1:2008, Information technology — Abstract Syntax Notation One (ASN.1): Specification
of basic notation.
[9] Document CCSDS 912.1-B-3, July 2010, is equivalent to ISO 22671:2011.
Page I-1
Add the following information to the reference indicated:
[I4] Document CCSDS 201.0-B-3, June 2000, is equivalent to ISO 12171:2002.
[I5] Document CCSDS 202.0-B-3, June 2001, is equivalent to ISO 12172:2003.
[I6] Document CCSDS 202.1-B-2, June 2001, is equivalent to ISO 12173:2003.
[I7] Document CCSDS 203.0-B-2, June 2001, is equivalent to ISO 12174:2003.
3 Revision of publication CCSDS 912.3-B-2
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 912.3-B-2. To this end, NASA will act as a liaison body between CCSDS and ISO.

2 © ISO 2011 – All rights reserved

Recommendation for Space Data System Standards
SPACE LINK EXTENSION—
FORWARD SPACE
PACKET SERVICE
SPECIFICATION
RECOMMENDED STANDARD
CCSDS 912.3-B-2
BLUE BOOK
July 2010
(Blank page)
4 © ISO 2011 – All rights reserved

CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
AUTHORITY
Issue: Recommended Standard, Issue 2
Date: July 2010
Location: Washington, DC, USA
This document has been approved for publication by the Management Council of the
Consultative 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 record 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
Washington, DC 20546-0001, USA
CCSDS 912.3-B-2 Page i July 2010
CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
STATEMENT OF INTENT
The Consultative Committee for Space Data Systems (CCSDS) is an organization officially
established by the management 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 Recommended Standards and are not
considered binding on any Agency.
This Recommended Standard is issued by, and represents the consensus of, the CCSDS
members. Endorsement of this Recommendation is entirely voluntary. Endorsement,
however, indicates the following understandings:
o Whenever a member establishes a CCSDS-related standard, this standard will be in
accord with the relevant Recommended Standard. Establishing such a standard
does not preclude other provisions which a member may develop.
o Whenever a member establishes a CCSDS-related standard, that member will
provide other CCSDS members with the following information:
-- The standard itself.
-- The anticipated date of initial operational capability.
-- The anticipated duration of operational service.
o Specific service arrangements shall be made via memoranda of agreement. Neither
this Recommended Standard nor any ensuing standard is a substitute for a
memorandum of agreement.
No later than five years from its date of issuance, this Recommended Standard will be
reviewed 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 canceled.
In those instances when a new version of a Recommended Standard is issued, existing
CCSDS-related member standards and implementations are not negated or deemed to be non-
CCSDS compatible. It is the responsibility of each member to determine when such
standards or implementations are to be modified. Each member is, however, strongly
encouraged to direct planning for its new standards and implementations towards the later
version of the Recommended Standard.
CCSDS 912.3-B-2 Page ii July 2010
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CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
FOREWORD
Through the process of normal evolution, it is expected that expansion, deletion, or
modification of this document may occur. This Recommended Standard 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 at 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.
CCSDS 912.3-B-2 Page iii July 2010
CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
At time of publication, the active Member and Observer Agencies of the CCSDS were:
Member Agencies
– Agenzia Spaziale Italiana (ASI)/Italy.
– Canadian Space Agency (CSA)/Canada.
– Centre National d’Etudes Spatiales (CNES)/France.
– China National Space Administration (CNSA)/People’s Republic of China.
– Deutsches Zentrum für Luft- und Raumfahrt e.V. (DLR)/Germany.
– European Space Agency (ESA)/Europe.
– Instituto Nacional de Pesquisas Espaciais (INPE)/Brazil.
– Japan Aerospace Exploration Agency (JAXA)/Japan.
– National Aeronautics and Space Administration (NASA)/USA.
– Russian Federal Space Agency (RFSA)/Russian Federation.
– UK Space Agency/United Kingdom.
Observer Agencies
– Austrian Space Agency (ASA)/Austria.
– Belgian Federal Science Policy Office (BFSPO)/Belgium.
– Central Research Institute of Machine Building (TsNIIMash)/Russian Federation.
– China Satellite Launch and Tracking Control General, Beijing Institute of Tracking
and Telecommunications Technology (CLTC/BITTT)/China.
– 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.
– Departamento de Ciência e Tecnologia Aeroespacial (DCTA)/Brazil.
– European 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 Research Organization (ISRO)/India.
– Institute of Space Research (IKI)/Russian Federation.
– KFKI Research Institute for Particle & Nuclear Physics (KFKI)/Hungary.
– Korea Aerospace Research Institute (KARI)/Korea.
– Ministry of Communications (MOC)/Israel.
– National Institute of Information and Communications Technology (NICT)/Japan.
– National Oceanic and Atmospheric Administration (NOAA)/USA.
– National Space Agency of the Republic of Kazakhstan (NSARK)/Kazakhstan.
– National Space Organization (NSPO)/Chinese Taipei.
– Naval Center for Space Technology (NCST)/USA.
– Scientific and Technological Research Council of Turkey (TUBITAK)/Turkey.
– Space and Upper Atmosphere Research Commission (SUPARCO)/Pakistan.
– Swedish Space Corporation (SSC)/Sweden.
CCSDS 912.3-B-2 Page iv July 2010
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CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
– United States Geological Survey (USGS)/USA.
CCSDS 912.3-B-2 Page v July 2010
CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
DOCUMENT CONTROL
Document Title Date Status
CCSDS Space Link Extension— November Original issue, superseded
912.3-B-1 Forward Space Packet 2004
Service Specification
CCSDS Space Link Extension—Forward July 2010 Current issue:
912.3-B-2 Space Packet Service Specification, – corrects/clarifies/
Recommended Standard, Issue 2 updates text and adds
the option of
picosecond resolution
to parameters
containing a time
value
NOTE – Substantive changes from the previous issue are indicated by change bars in the
inside margin.
CCSDS 912.3-B-2 Page vi July 2010
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CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
CONTENTS
Section Page
1 INTRODUCTION. 1-1

1.1 PURPOSE OF THIS RECOMMENDED STANDARD . 1-1
1.2 SCOPE . 1-1
1.3 APPLICABILITY . 1-2
1.4 RATIONALE . 1-2
1.5 DOCUMENT STRUCTURE . 1-3
1.6 DEFINITIONS, NOMENCLATURE, AND CONVENTIONS . 1-5
1.7 REFERENCES . 1-14

2 DESCRIPTION OF THE FORWARD SPACE PACKET SERVICE . 2-1

2.1 OVERVIEW . 2-1
2.2 SPACE LINK EXTENSION REFERENCE MODEL . 2-1
2.3 SERVICE MANAGEMENT . 2-3
2.4 ARCHITECTURE MODEL—FUNCTIONAL VIEW . 2-3
2.5 ARCHITECTURE MODEL—CROSS SUPPORT VIEW . 2-8
2.6 FUNCTIONAL DESCRIPTION . 2-9
2.7 OPERATIONAL SCENARIO . 2-16
2.8 SECURITY ASPECTS OF THE SLE FORWARD SPACE PACKET (FSP)
TRANSFER SERVICE . 2-17

3 FSP SERVICE OPERATIONS . 3-1

3.1 GENERAL CONSIDERATIONS . 3-1
3.2 FSP-BIND . 3-10
3.3 FSP-UNBIND . 3-16
3.4 FSP-START . 3-20
3.5 FSP-STOP . 3-24
3.6 FSP-TRANSFER-DATA . 3-27
3.7 FSP-ASYNC-NOTIFY . 3-38
3.8 FSP-SCHEDULE-STATUS-REPORT . 3-52
3.9 FSP-STATUS-REPORT . 3-56
3.10 FSP-GET-PARAMETER . 3-63
3.11 FSP-THROW-EVENT . 3-69
3.12 FSP-INVOKE-DIRECTIVE . 3-74
3.13 FSP-PEER-ABORT . 3-79

4 FSP PROTOCOL . 4-1

4.1 GENERIC PROTOCOL CHARACTERISTICS . 4-1
CCSDS 912.3-B-2 Page vii July 2010
CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
4.2 FSP SERVICE PROVIDER BEHAVIOR . 4-4
CCSDS 912.3-B-2 Page viii July 2010
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CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
CONTENTS (continued)
Section Page
ANNEX A DATA TYPE DEFINITIONS (NORMATIVE) . A-1
ANNEX B FSP QUEUES AND MULTIPLEXING BEHAVIOR DEFINITION
(NORMATIVE) .B-1
ANNEX C PRODUCTION STATUS (NORMATIVE) . C-1
ANNEX D FUNCTIONAL GROUP PRODUCTION REQUIREMENTS
FOR FSP (NORMATIVE) . D-1
ANNEX E CONFORMANCE MATRIX (NORMATIVE) .E-1
ANNEX F INDEX TO DEFINITIONS (INFORMATIVE) . F-3
ANNEX G ACRONYMS (INFORMATIVE) . G-1
ANNEX H THROW EVENT DEFINITIONS (INFORMATIVE) . H-1
ANNEX I INFORMATIVE REFERENCES (INFORMATIVE) . I-1
Figure
1-1 SLE Services Documentation . 1-4
2-1 Forward Telecommand Functional Groups . 2-4
2-2 FSP Service Production and Provision . 2-7
2-3 Example of the Management and Provision of FSP Service . 2-8
2-4 Simplified FSP Service Provider State Transition Diagram . 2-11
2-5 Communications Realization of FSP Service . 2-14
B-1 FSP MAP and TC Frame Multiplexing . B-1
B-2 MAP and VC Multiplexing . B-2
B-3 FSP Queues . B-5
C-1 FSP Production Status Diagram .C-1

Table
2-1 FSP Service Operations . 2-10
3-1 Setting of FSP Service Operation Parameters . 3-6
3-2 FSP-BIND Parameters . 3-11
3-3 FSP-UNBIND Parameters . 3-17
3-4 FSP-START Parameters . 3-20
3-5 FSP-STOP Parameters . 3-24
3-6 FSP-TRANSFER-DATA Parameters . 3-28
3-7 FSP-ASYNC-NOTIFY Parameters . 3-38
3-8 FSP-SCHEDULE-STATUS-REPORT Parameters . 3-52
3-9 FSP-STATUS-REPORT Parameters . 3-56
3-10 FSP-GET-PARAMETER Parameters . 3-63
3-11 FSP Service Parameters . 3-64
3-12 FSP-THROW-EVENT Parameters . 3-70
CCSDS 912.3-B-2 Page ix July 2010
CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
CONTENTS (continued)
Table Page
3-13 FSP-INVOKE-DIRECTIVE Parameters . 3-74
3-14 FSP-PEER-ABORT Parameters . 3-79
4-1 Provider Behavior . 4-6
4-2 Event Description References . 4-10
4-3 Predicate Definitions . 4-11
4-4 Boolean Flags. 4-11
4-5 Compound Action Definitions . 4-12
C-1 Production Status Transitions .C-2
C-2 Effects of Production Status on Operations .C-4
D-1 Forward CLTU Generation Aggregate Production Status . D-3
D-2 Forward TC VC Data Insertion Aggregate Production Status . D-5
E-1 Conformance Matrix for FSP Service (Operations) . E-1
E-2 Conformance Matrix for FSP Service (Other Requirements) . E-2
H-1 Throw Event Examples . H-1

CCSDS 912.3-B-2 Page x July 2010
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CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
1 INTRODUCTION
1.1 PURPOSE OF THIS RECOMMENDED STANDARD
This Recommended Standard defines the Forward Space Packet (FSP) service in
conformance with the transfer services specified in reference [1], Cross Support Reference
Model―Part 1: SLE Services. The FSP service is a Space Link Extension (SLE) transfer
service that enables a mission to send Space Packets to a spacecraft in sequence-controlled or
expedited mode.
1.2 SCOPE
This Recommended Standard defines, in an abstract manner, the FSP service in terms of:
a) the operations necessary to provide the transfer service;
b) the parameter data associated with each operation;
c) the behaviors that result from the invocation of each operation; and
d) the relationship between, and the valid sequence of, the operations and resulting
behaviors.
It does not specify:
a) individual implementations or products;
b) the implementation of entities or interfaces within real systems;
c) the methods or technologies required to radiate Space Packets to a spacecraft and to
acquire telemetry frames from the signals received from that spacecraft for extraction
of the Operational Control Field;
d) the methods or technologies required for communications; or
e) the management activities necessary to schedule, configure, and control the FSP
service.
NOTE – While the FSP service as described in reference [1] is conceived to handle a
variety of packet data structures, this version of the FSP Recommended Standard
is restricted to the handling of Space Packets as defined in reference [6].
This version of the FSP Recommended Standard is specific to the transfer of Space Packets
to be transmitted via the Telecommand protocol stack as defined in references [3], [4], and
[5]. The Cross Support Reference Model (reference [1]) specifies that the FSP service may
also be used in conjunction with the Advanced Orbiting System protocol stack, but that mode
of operation is outside the scope of this version of the Recommended Standard.
CCSDS 912.3-B-2 Page 1-1 July 2010
CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
The FSP service is provided in the online delivery mode, as defined in reference [1]. The
offline delivery mode is the subject of further study.
1.3 APPLICABILITY
1.3.1 APPLICABILITY OF THIS RECOMMENDED STANDARD
This Recommended Standard provides a basis for the development of real systems that
implement the FSP service. Implementation of the FSP service in a real system additionally
requires the availability of a communications service to convey invocations and returns of
FSP service operations between FSP service users and providers. This Recommended
Standard requires that such a communications service ensures that invocations and returns of
operations are transferred:
a) in sequence;
b) completely and with integrity;
c) without duplication;
d) with flow control that notifies backpressure to the application layer in the event of
congestion; and
e) with notification to the application layer in the event that communications between
the FSP service user and the FSP service provider are disrupted, possibly resulting in
a loss of data.
It is the specific intent of this Recommended Standard to define the FSP service in a manner
that is independent of any particular communications services, protocols, or technologies.
1.3.2 LIMITS OF APPLICABILITY
This Recommended Standard specifies the FSP service that may be provided by an SLE
System for inter-Agency cross support. It is neither a specification of, nor a design for, real
systems that may be implemented for the control and monitoring of existing or future
missions.
1.4 RATIONALE
The goal of this Recommended Standard is to create a standard for interoperability between
the tracking stations and/or ground data handling systems of various agencies and the users of
forward services.
CCSDS 912.3-B-2 Page 1-2 July 2010
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CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
1.5 DOCUMENT STRUCTURE
1.5.1 ORGANIZATION
This Recommended Standard is organized as follows:
a) section 1 provides the purpose, scope, applicability, and rationale of this
Recommended Standard and lists definitions, nomenclature, conventions, and
references used throughout the Recommended Standard;
b) section 2 provides an overview of the FSP service including a functional description,
the service management context, and protocol considerations;
c) section 3 specifies the operations of the FSP service;
d) section 4 specifies the dynamic behavior of the FSP service in terms of the state
transitions of the FSP service provider;
e) annex A provides a formal specification of FSP service data types, using the Abstract
Syntax Notation One (ASN.1);
f) annex B provides a specification of the multiplexing between concurrent FSP service
instances sharing the same TC Virtual Channel (VC) as well as the multiplexing
between TC VCs sharing the same physical space link data channel;
g) annex C presents the FSP production status and its transitions;
h) annex D defines the production requirements the FSP service imposes on the forward
Functional Groups;
i) annex E provides a conformance matrix that defines what capabilities must be
provided for an implementation to be considered compliant with this Recommended
Standard;
j) annex F lists all terms used in this document and identifies where they are defined;
k) annex G lists all acronyms used within this document;
l) annex H contains examples of usage of the FSP-THROW-EVENT operation;
m) annex I contains a list of informative references.
1.5.2 SLE SERVICES DOCUMENTATION TREE
This Recommended Standard is based on the architectural model for cross support defined in
reference [1]. It expands upon the concept of an SLE Transfer Service as interactions
between an SLE Mission User Entity (MUE) and an SLE Transfer Service provider for the
purpose of providing the FSP Transfer Service.
CCSDS 912.3-B-2 Page 1-3 July 2010
CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
This Recommended Standard is part of a suite of documents specifying the SLE services.
The SLE services constitute one of the three types of Cross Support Services:
a) Part 1: SLE Services;
b) Part 2: Ground Communications Services;
c) Part 3: Ground Domain Services.
The basic organization of the SLE services documentation is shown in figure 1-1. The
documents are described in the following paragraphs.
Space Link Extension
Cross Support
Cross Support Concept SLE Executive
Reference Model
Part 1: SLE Services Summary
Part 1: SLE Services
SLE Transfer Services
SLE Transfer Services
Forward SLE Service
Return SLE Service
Specifications
Specifications
SLE Service
Management Suite
SLE API for Internet Protocol for
Transfer Services Transfer Services
Recommended Recommended Informational
Legend:
Record (Yellow)
Standard (Blue) Practice (Magenta) Report (Green)

Figure 1-1: SLE Services Documentation
a) Cross Support Concept — Part 1: Space Link Extension Services (reference [I3]): a
Report introducing the concepts of cross support and SLE services;
b) Cross Support Reference Model — Part 1: Space Link Extension Services (reference
[1]): a Recommended Standard that defines the reference model that provides a
common framework and terminology for the specification of SLE services;
c) Return SLE Transfer Service Specifications: a set of Recommended Standards that
will provide specification of all return link SLE transfer services.
d) Forward SLE Transfer Service Specifications: a set of Recommended Standards that
will provide specification of all forward link SLE transfer services (this
Recommended Standard is one of the specifications in that set);
CCSDS 912.3-B-2 Page 1-4 July 2010
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CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
e) SLE API for Transfer Services Specifications: a set of Recommended Practices that
provide specifications of an Application Program Interface; a set of Recommended
Standards that provide specifications of an Application Program Interface and a
mapping to TCP/IP as underlying communications service for SLE services;
f) Internet Protocol for Transfer Services: defines a protocol for transfer of SLE
Protocol Data Units using TCP/IP as underlying communications service for SLE
services;
g) SLE Service Management Specification Suite: a set of Recommended Standards that
establish the basis for SLE service management.
1.6 DEFINITIONS, NOMENCLATURE, AND CONVENTIONS
1.6.1 DEFINITIONS
1.6.1.1 Definitions from Open Systems Interconnection (OSI) Basic Reference Model
This Recommended Standard makes use of a number of terms defined in reference [8]. The
use of those terms in this Recommended Standard shall be understood in a generic sense, i.e.,
in the sense that those terms are generally applicable to technologies that provide for the
exchange of information between real systems. Those terms are:
a) abstract syntax;
b) application entity;
c) application layer;
d) flow control;
e) Open Systems Interconnection (OSI);
f) real system;
g) service access point (SAP).
1.6.1.2 Definitions from Abstract Syntax Notation One
This Recommended Standard makes use of the following terms defined in reference [7]:
a) Abstract Syntax Notation One (ASN.1);
b) object identifier;
c) (data) type;
d) (data) value.
CCSDS 912.3-B-2 Page 1-5 July 2010
CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
NOTE – In annex A of this Recommended Standard, ASN.1 is used for specifying the
abstract syntax of the invocations and returns of the operations of the FSP
service. The use of ASN.1 as a descriptive language is intended to support the
specification of the abstract FSP service; it is not intended to constrain
implementations. In particular, there is no requirement for implementations to
employ ASN.1 encoding rules. ASN.1 is simply a convenient tool for formally
describing the abstract syntax of the invocations and returns of the FSP service.
1.6.1.3 Definitions from TC Synchronization and Channel Coding
This Recommended Standard makes use of the following term defined in reference [3]:
Communications Link Transmission Unit (CLTU).
1.6.1.4 Definitions from TC Space Data Link Protocol
This Recommended Standard makes use of the following terms defined in reference [4]:
a) AD, BD, BC;
b) Communications Link Control Word (CLCW);
c) Communications Operation Procedure (COP);
d) Control Word Type;
e) Frame Operation Procedure (FOP);
f) Frame Sequence Number;
g) Multiplexer Access Point (MAP);
h) Operational Control Field (OCF);
i) Segment;
j) Telecommand Transfer Frame (TC Transfer Frame or TC frame);
k) Virtual Channel (VC).
1.6.1.5 Definitions from Communications Operation Procedure-1
This Recommended Standard makes use of the following terms defined in reference [5]:
a) FOP_Sliding_Window_Width;
b) Receiver_Frame_Sequence_Number V(R);
c) Timeout_Type;
CCSDS 912.3-B-2 Page 1-6 July 2010
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CCSDS RECOMMENDED STANDARD FOR SLE FSP SERVICE
d) Transmitter_Frame_Sequence_Number V(S);
e) T1_Initial.
1.6.1.6 Definitions from Space Packet Protocol
This Recommended Standard makes use of the following terms defined in reference [6]:
a) Application Process Identifier (APID);
b) Space Packet.
1.6.1.7 Definitions from SLE Reference Model
This Recommended Standard makes use of the following terms defined in reference [1]:
a) abstract binding;
b) abstract object;
c) abstract port;
d) abstract service;
e) Forward CLTU SLE data channel (Forward CLTU data channel);
f) Forward Space Packet channel (FSP channel);
g) Forward Space Packet service (FSP service);
h) Forward Telecommand Frame SLE data channel (Forward TC Frame data channel);
i) invoker;
j) Mission Data Operation System (MDOS);
k) Mission User Entity (MUE);
l) offline delivery mode;
m) online delivery mode;
n) operation;
o) Operational Control Field SLE data channel (OCF data channel);
p) performer;
q) physical channel;
r) service agreement;
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s) service provider (provider);
t) service user (user);
u) SLE Complex;
v) SLE Complex Management;
w) SLE data channel;
x) SLE Functional Group (SLE-FG);
y) SLE protocol data unit (SLE-PDU);
z) SLE service data unit (SLE-SDU);
aa) SLE service package;
bb) SLE transfer service instance;
cc) SLE transfer service production;
dd) SLE transfer service provision;
ee) SLE Utilization Management;
ff) space link;
gg) space link data channel;
hh) space link data unit (SL-DU);
ii) space link session.
1.6.1.8 Additional Definitions
For the purposes of this Recommended Standard, the following definitions also apply.
1.6.1.8.1 Acknowledged (Space Packet)
A Space Packet is said to be acknowledged when evaluation of the CLCWs returned by the
space element shows that all TC frames containing parts of the Space Packet reported have
been acknowledged by the space element.
NOTE — This status applies only to the sequence-controlled transmission mode (AD).
Although a Space Packet is ‘acknowledged’, packet re-assembly and/or execution
may still fail. This can only be determined by examining telemetry.
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1.6.1.8.2 Association
An association is a cooperative relationship between an SLE service-providing application
entity and an SLE service-using application entity. An association is formed by the exchange
of SLE protocol data units through the use of an underlying communications service.
1.6.1.8.3 CLTU Transfer Data SLE-SDU
A CLTU Transfer Data SLE-SDU contains a CLTU plus information (see D1.2.2.2) required
by the Forward TC Space Link Processing SLE Functional Group (see 2.4.1.4) to process that
CLTU. In the context of the FSP SLE transfer service, the CLTU Transfer Data SLE-SDU is
generated by the Forward CLTU Generation SLE Functional Group (see 2.4.1.3).
NOTE – When the F-CLTU transfer service is used, the CLTU Transfer Data SLE-SDU is
carried (along with other information) in the CLTU-TRANSFER-DATA
invocation.
1.6.1.8.4 Communications Service
A communications service is a capability that enables an SLE service-providing application
entity and an SLE service-using application entity to exchange information.
NOTE – If an SLE service user and an SLE service provider are implemented using
different communications services, then interoperability between them is possible
only by means of a suitable gateway. Adherence to this Recommended Standard
ensures, at least in principle, that it is possible to construct such a gateway.
1.6.1.8.5 Confirmed Operation
A confirmed operation is an operation that requires the performer to return a report of its
outcome to the invoker.
1.6.1.8.6 Initiator
The initiator is the object that issues the request to bind to another object (the responder).
NOTE – In other words, the initiator is always the invoker of the request to bind to another
object. Therefore, in the context of the request to bind, the terms ‘initiator’ and
‘invoker’ refer to the same object and are synonyms.
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1.6.1.8.7 Invocation
The invocation of an operation is the making of a request by an object (the invoker) to
another object (the performer) to carry out the operation.
1.6.1.8.8 Parameter
A parameter of an operation is data that may accompany the operation’s invocation or return.
NOTE – The term parameter is also used to refer to mission-dependent configuration
information used in the production or provision of the service.
1.6.1.8.9 Performance
The performance of an operation is the carrying out of the operation by an object (the
performer).
1.6.1.8.10 Port Identifier
A port identifier identifies a source or a destination in a communications system.
NOTE – See 2.6.4.5 for more information.
1.6.1.8.11 Radiated (Space Packet)
A Space Packet is said to be radiated when, based on the ground equipment monitoring, the
FSP production process can assume that all the CLTUs containing parts of the Space Packet
reported have been transmitted to the spacecraft.
1.6.1.8.12 Responder
The responder is the object that receives a request to bind and completes the binding (if
possible) with the initiator in order for a service association to exist between the two objects.
NOTE – In other words, the responder is always the performer of the binding. Therefore,
in the context of binding, the terms ‘responder’ and ‘performer’ refer to the same
object and are synonyms.
1.6.1.8.13 Return
The return of an operation is a report, from the performer to the invoker, of the outcome of
the performance of the operation.
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1.6.1.8.14 Service Instance Provision Period
A service instance provision period is the time during which a service instance (i.e., the
capability to transfer one or more SLE data channels of a given type) is scheduled to be
provided.
1.6.1.8.15 TC Frame Transfer Data SLE-SDU
A TC Frame Transfer Data SLE-SDU contains a TC Frame plus information (see D1.3.2.2)
required by the Forward CLTU Generation SLE Functional Group (see 2.4.1.3) to process
that TC frame. In the context of the FSP SLE transfer service, the TC Frame Transfer Data
SLE-SDU is generated by the Forward TC VC Data Insertion SLE Functional Group (see
2.4.1.2).
1.6.1.8.16 Unconfirmed Operation
An unconfirmed operation is an operation that does not require a report of its outcome to be
returned to the invoker by the performer.
1.6.2 NOMENCLATURE
The following nomenclature applies throughout this Recommended Standard:
a) the words ‘shall’ and ‘must’ imply a binding and verifiable specification;
b) the word ‘should’ implies an optional, but desirable, specification;
c) the word ‘may’ implies an optional specification;
d) the words ‘is’, ‘are’, and ‘will’ imply statements of fact.
1.6.3 CONVENTIONS
1.6.3.1 Specification of Operations
1.6.3.1.1 General
Section 3 of this Recommended Standard specifies the operations that constitute the FSP
service. The specification of each operation is divided into subsections as follows:
1.6.3.1.2 Purpose Subsection
The Purpose subsection briefly describes the purpose and functioning of the operation.
Additionally, it indicates whether the operation may be invoked by the user, provider, or
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