ISO 22670:2021

Space data and information transfer systems — Space link extension (SLE) — Return-channel-frames service specification

The purpose of this document is to define the Space Link Extension (SLE) Return Channel Frames (RCF) service in conformance with the SLE Reference Model (reference [1]). The RCF service is an SLE transfer service that delivers to a mission user all telemetry frames from one master channel or one virtual channel. This document defines, in an abstract manner, the RCF service in terms of: the operations necessary to provide the service; the parameter data associated with each operation; the behaviors that result from the invocation of each operation; and the relationship between, and the valid sequence of, the operations and resulting behaviors. It does not specify: individual implementations or products; the implementation of entities or interfaces within real systems; the methods or technologies required to acquire telemetry frames from signals received from a spacecraft; the methods or technologies required to provide a suitable environment for communications; or the management activities required to schedule, configure, and control the RCF service. NOTE – Reference [1] defines the Return Master Channel Frames (Rtn MC Frames) service and the Return Virtual Channel Frames (Rtn VC Frames) service as two distinct services. Subsequent study has indicated that it is preferable to define one service that provides the functionality of both. The RCF service defined here does just that. It is anticipated that a future issue of reference [1] will take the same approach, deleting the Rtn MC Frames and Rtn VC Frames services and replacing them with the RCF service.

Systèmes de transfert des informations et données spatiales — Extension de liaisons spatiales (SLE) — Service de réseau pour liaison retour

General Information

• Status: Published
• Publication Date: 29-Jun-2021
• ICS: 49.140 - Space systems and operations
• Technical Committee: ISO/TC 20/SC 13 - Space data and information transfer systems
• Drafting Committee: ISO/TC 20/SC 13 - Space data and information transfer systems
• Current Stage: 6060 - International Standard published
• Start Date: 30-Jun-2021
• Due Date: 14-Sep-2020
• Completion Date: 30-Jun-2021

Relations

• Revises: ISO 22670:2013 - Space data and information transfer systems — Space link extension (SLE) — Return-channel-frames service
• Effective Date: 23-Sep-2017

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 22670
Third edition
2021-06
Space data and information transfer
systems — Space link extension (SLE)
— Return-channel-frames service
specification
Systèmes de transfert des informations et données spatiales —
Extension de liaisons spatiales (SLE) — Service de réseau pour liaison
retour
Reference number
ISO 22670:2021(E)
©
ISO 2021

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ISO 22670:2021(E)

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© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
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ISO 22670:2021(E)
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
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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, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted (see www.iso.org/directives).
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. 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 received (see 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.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www.iso.org/iso/foreword.html.
This document was prepared by the Consultative Committee for Space Data Systems (CCSDS) (as CCSDS
911.2-B-3, August 2016) and was adopted (without modifications) by Technical Committee ISO/TC 20,
Space vehicles, Subcommittee SC 13, Space data and information transfer systems.
This third edition cancels and replaces the second edition (ISO 22670:2013), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— adds clarifications and corrections;
— adds production status annex.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF 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 . 1-2
1.6 DEFINITIONS, NOMENCLATURE, AND CONVENTIONS . 1-5
1.7 REFERENCES . 1-13
2 DESCRIPTION OF THE RETURN CHANNEL FRAMES SERVICE . 2-1
2.1 OVERVIEW . 2-1
2.2 SPACE LINK EXTENSION REFERENCE MODEL . 2-2
2.3 SERVICE MANAGEMENT . 2-3
2.4 ARCHITECTURE MODEL—FUNCTIONAL VIEW . 2-4
2.5 ARCHITECTURE MODEL—CROSS SUPPORT VIEW . 2-7
2.6 FUNCTIONAL DESCRIPTION . 2-8
2.7 OPERATIONAL SCENARIO . 2-18
2.8 SECURITY ASPECTS OF THE SLE RCF TRANSFER SERVICE . 2-19
3 RCF SERVICE OPERATIONS . 3-1
3.1 GENERAL CONSIDERATIONS . 3-1
3.2 RCF-BIND . 3-15
3.3 RCF-UNBIND . 3-22
3.4 RCF-START . 3-26
3.5 RCF-STOP . 3-32
3.6 RCF-TRANSFER-DATA . 3-34
3.7 RCF-SYNC-NOTIFY . 3-38
3.8 RCF-SCHEDULE-STATUS-REPORT . 3-42
3.9 RCF-STATUS-REPORT . 3-46
3.10 RCF-GET-PARAMETER . 3-49
3.11 RCF-PEER-ABORT . 3-53
4 RCF PROTOCOL . 4-1
4.1 GENERIC PROTOCOL CHARACTERISTICS . 4-1
4.2 RCF SERVICE PROVIDER BEHAVIOR . 4-4
CCSDS 911.2-B-3 Page vi August 2016
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CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
CONTENTS (continued)
Section Page

ANNEX A DATA TYPE DEFINITIONS (NORMATIVE) . A-1
ANNEX B PRODUCTION STATUS (NORMATIVE) .B-1
ANNEX C CONFORMANCE MATRIX (NORMATIVE) . C-1
ANNEX D INDEX TO DEFINITIONS (INFORMATIVE) . D-1
ANNEX E ACRONYMS (INFORMATIVE) .E-1
ANNEX F INFORMATIVE REFERENCES (INFORMATIVE) . F-1
Figure
1-1 SLE Services Documentation . 1-4
2-1 Return Frame Processing SLE-FG . 2-4
2-2 RCF Service Production and Provision . 2-7
2-3 Example of the Management and Provision of RCF Service . 2-8
2-4 Simplified RCF Service Provider State Transition Diagram . 2-11
2-5 Communications Realization of RCF Service . 2-13
2-6 Buffers and Delivery Modes . 2-18
B-1 RCF Production Status Transitions .B-1

Table
2-1 RCF Operations . 2-9
3-1 Setting of RCF Service Configuration Parameters . 3-6
3-2 RCF-BIND Parameters . 3-16
3-3 RCF-UNBIND Parameters . 3-23
3-4 RCF-START Parameters . 3-27
3-5 RCF-STOP Parameters . 3-32
3-6 RCF-TRANSFER-DATA Parameters . 3-34
3-7 RCF-SYNC-NOTIFY Parameters . 3-38
3-8 RCF-SCHEDULE-STATUS-REPORT Parameters . 3-43
3-9 RCF-STATUS-REPORT Parameters . 3-46
3-10 RCF-GET-PARAMETER Parameters . 3-49
3-11 RCF Parameters . 3-51
3-12 RCF-PEER-ABORT Parameters . 3-53
4-1 Provider Behavior . 4-6
4-2 Event Description References . 4-13
4-3 Predicate Descriptions . 4-13
4-4 Boolean Flags . 4-14
4-5 Compound Action Definitions . 4-14
B-1 Production Status Changes and Notifications .B-2
B-2 Effect of Production Status on Operations .B-3
C-1 Conformance Matrix for RCF Service (Operations) .C-1
C-2 Conformance Matrix for RCF Service (Other Requirements) .C-2
CCSDS 911.2-B-3 Page vii August 2016
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
1 INTRODUCTION
1.1 PURPOSE OF THIS RECOMMENDED STANDARD
The purpose of this Recommended Standard is to define the Space Link Extension (SLE)
Return Channel Frames (RCF) service in conformance with the SLE Reference Model
(reference [1]). The RCF service is an SLE transfer service that delivers to a mission user all
telemetry frames from one master channel or one virtual channel.
NOTE – Reference [1] defines the Return Master Channel Frames (Rtn MC Frames)
service and the Return Virtual Channel Frames (Rtn VC Frames) service as two
distinct services. Subsequent study has indicated that it is preferable to define one
service that provides the functionality of both. The RCF service defined here
does just that. It is anticipated that a future issue of reference [1] will take the
same approach, deleting the Rtn MC Frames and Rtn VC Frames services and
replacing them with the RCF service.
1.2 SCOPE
This Recommended Standard defines, in an abstract manner, the RCF service in terms of:
a) the operations necessary to provide the 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 acquire telemetry frames from signals
received from a spacecraft;
d) the methods or technologies required to provide a suitable environment for
communications; or
e) the management activities required to schedule, configure, and control the RCF service.
CCSDS 911.2-B-3 Page 1-1 August 2016
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CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
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 RCF service. Implementation of the RCF service in a real system additionally
requires the availability of a communications service to convey invocations and returns of
RCF service operations between RCF service users and providers. This Recommended
Standard requires that such a communications service must ensure 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 the application layer in the event of congestion; and
e) with notification to the application layer in the event that communications between
the RCF service user and the RCF service provider are disrupted, possibly resulting in
a loss of data.
It is the specific intent of this Recommended Standard to define the RCF 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 RCF service that may be provided by an SLE
Complex 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 or ground data handling systems of various Agencies and the consumers
of spacecraft telemetry.
1.5 DOCUMENT STRUCTURE
1.5.1 ORGANIZATION
This document is organized as follows:
CCSDS 911.2-B-3 Page 1-2 August 2016
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
a) section 0 presents the purpose, scope, applicability and rationale of this
Recommended Standard and lists the definitions, conventions, and references used
throughout the Recommended Standard;
b) section 2 provides an overview of the RCF service including a functional description,
the service management context, and protocol considerations;
c) section 3 specifies the operations of the RCF service;
d) section 4 specifies the dynamic behavior of the RCF service in terms of the state
transitions of the RCF service provider;
e) annex A provides a formal specification of RCF service data types using Abstract
Syntax Notation One (ASN.1);
f) annex B specifies the relationship of the RCF service provision to the production
status;
g) annex C provides a conformance matrix that defines what capabilities must be
provided for an implementation to be considered compliant with this Recommended
Standard;
h) annex D lists all terms used in this Recommended Standard and identifies where they
are defined;
i) annex E lists all acronyms used within this document;
j) annex F provides a list of informative references.
1.5.2 SLE SERVICES DOCUMENTATION TREE
This Recommended Standard is based on the cross support model defined in the SLE
Reference Model (reference [1]). It expands upon the concept of an SLE transfer service as
an interaction between an SLE Mission User Entity (MUE) and an SLE transfer service
provider for the purpose of providing the RCF transfer 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 Domain Services;
c) Part 3: Ground Communications Services.
The basic organization of the SLE services documentation is shown in figure 1-1. The
various documents are described in the following subsections.
CCSDS 911.2-B-3 Page 1-3 August 2016
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
Space Link Extension
Cross Support
Cross Support Concept SLE Executive
Reference Model
Part 1: SLE Services Summary
Part 1: SLE 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 [F2]): a
Report introducing the concepts of cross support and the SLE services;
b) Cross Support Reference Model—Part 1: Space Link Extension Services (reference
[1]): a Recommended Standard that defines the framework and terminology for the
specification of SLE services;
c) SLE Return Service Specifications: a set of Recommended Standards that will
provide specification of all return link SLE services (this Recommended Standard is
one of the specifications in that set);
d) SLE Forward Service Specifications: a set of Recommended Standards that will
provide specification of all forward link SLE services;
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 Specifications: a set of Recommended Standards that
establish the basis of SLE service management.
CCSDS 911.2-B-3 Page 1-4 August 2016
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE

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 [6]. 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) application process;
e) flow control;
f) Open Systems Interconnection (OSI);
g) real system;
h) 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.
NOTE – In annex A of this Recommended Standard, ASN.1 is used for specifying the
abstract syntax of RCF service operation invocations and returns. The use of
ASN.1 as a descriptive language is intended to support the specification of the
abstract RCF 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 RCF service operation invocations and returns.
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
1.6.1.3 Definitions from TM Synchronization and Channel Coding
This Recommended Standard makes use of the following terms defined in reference [2]:
a) Attached Sync Marker;
b) Reed-Solomon check symbols;
c) Reed-Solomon code.
1.6.1.4 Definitions from TM Space Data Link Protocol
This Recommended Standard makes use of the following term defined in reference [3]:
a) Frame Error Control Field (FECF);
b) TM Transfer Frame.
1.6.1.5 Definitions from AOS Space Data Link Protocol
This Recommended Standard makes use of the following terms defined in reference [4]:
a) AOS Transfer Frame;
b) Frame Error Control Field (FECF);
1.6.1.6 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) invoker;
f) Mission Data Operation System (MDOS);
g) Mission User Entity (MUE);
h) offline delivery mode;
i) online delivery mode;
j) operation;
k) performer;
CCSDS 911.2-B-3 Page 1-6 August 2016
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
l) physical channel;
m) return data;
n) Return All Frames channel (RAF channel);
o) Return All Frames service (RAF service);
p) Return Master Channel Frame Service (MC service)
q) Return Virtual Channel Frame Service (VC Frame service)
r) service agreement;
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.
1.6.1.7 Additional Definitions
1.6.1.7.1 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
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
exchange of SLE protocol data units through the use of an underlying communications
service.
1.6.1.7.2 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.
1.6.1.7.3 Confirmed Operation
A confirmed operation is an operation that requires the performer to return a report of its
outcome to the invoker.
1.6.1.7.4 Delivery Criteria
Delivery criteria are rules that determine whether a data unit acquired from the space link by
an SLE service provider shall be delivered to a user.
NOTE – For RCF service, the delivery criteria are:
a) the Earth Receive Time (ERT) of the frame is within the period defined by the
start and stop times specified in the RCF-START operation;
b) the spacecraft identifier (SCID) of the frame matches the SCID of the global
VCID specified in the RCF-START operation; and
c) the Virtual Channel Identifier (VCID) of the frame matches the VCID of the
global VCID specified in the RCF-START operation.
1.6.1.7.5 Frame Error Control Field
The Frame Error Control Field (FECF) of a frame is the FECF of a TM Transfer Frame
(reference [3]) or the FECF of an AOS Transfer Frame (reference [4]), as applicable.
1.6.1.7.6 Frame Version Number
The frame version number is either the transfer frame version number (reference [3]) or the
version number in the AOS transfer frame primary header (reference [4]).
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
NOTE – The definitions of frame version number given in references [3] and [4] are
equivalent. If a CCSDS-compatible telemetry frame is known to contain no
errors, the frame version number enables one to distinguish between a transfer
frame and an AOS transfer frame.
1.6.1.7.7 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.
1.6.1.7.8 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.
1.6.1.7.9 Master Channel
The sequence of all telemetry frames with the same Transfer Frame Version Number
(TFVN) and the same SCID on the same physical channel constitutes a master channel.
NOTE – Depending on the TFVN, the definition of SCID is as given in either reference
[3] or reference [4].
1.6.1.7.10 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.
1.6.1.7.11 Performance
The performance of an operation is the carrying out of the operation by an object (the
performer).
1.6.1.7.12 Port Identifier
A port identifier identifies a source or a destination in a communications system.
NOTE – See 2.6.4.5 for more information.
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CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
1.6.1.7.13 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.
1.6.1.7.14 Return
The return of an operation is a report, from the performer to the invoker, of the outcome of
the performance of the operation.
1.6.1.7.15 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.
NOTE – Reaching of the beginning of this period constitutes the event ‘start of service
instance provision period’ (see 4.2.2).
1.6.1.7.16 Spacecraft Identifier
The spacecraft identifier (SCID) of a telemetry frame is as defined in reference [3] if the
frame is a TM Transfer Frame or as defined in reference [4] if the frame is an AOS Transfer
Frame.
1.6.1.7.17 Telemetry Frame
A telemetry frame is a TM Transfer Frame (as defined in reference [3]) or an AOS Transfer
Frame (as defined in reference [4]). In case a distinction of the frame versions is necessary,
the full term as per references [3] or [4] is used.
1.6.1.7.18 Transfer Frame Version Number
The Transfer Frame Version Number (TFVN) is either the TFVN as defined in reference [3]
or the TFVN as defined in reference [4].
NOTE – The definitions of TFVN given in references [3] and [4] are equivalent. If a
CCSDS-compatible telemetry frame is known to contain no errors, the TFVN
enables one to distinguish between a TM Transfer Frame and an AOS Transfer
Frame.
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ISO 22670:2021(E)
CCSDS RECOMMENDED STANDARD FOR SLE RCF SERVICE
1.6.1.7.19 Unconfirmed Operation
An unconfirmed operation is an operation that does not require a report of i
...