Space engineering
Adoption Notice of CCSDS 132.0-B-3, TM Space Data Link Protocol
Foreword
This Adoption Notice is one document of the series of ECSS Standards intended to be applied together for the management, engineering, product assurance and sustainability in space projects and applications. ECSS is a cooperative effort of the European Space Agency, national space agencies and European industry associations for the purpose of developing and maintaining common standards. Requirements in this Standard are defined in terms of what shall be accomplished, rather than in terms of how to organize and perform the necessary work. This allows existing organizational structures and methods to be applied where they are effective, and for the structures and methods to evolve as necessary without rewriting the standards.
This Adoption Notice has been prepared by the ECSS Space Communications Working Group, reviewed by the ECSS Executive Secretariat and approved by the ECSS Technical Authority.
Disclaimer
ECSS does not provide any warranty whatsoever, whether expressed, implied, or statutory, including, but not limited to, any warranty of merchantability or fitness for a particular purpose or any warranty that the contents of the item are error-free. In no respect shall ECSS incur any liability for any damages, including, but not limited to, direct, indirect, special, or consequential damages arising out of, resulting from, or in any way connected to the use of this document, whether or not based upon warranty, business agreement, tort, or otherwise; whether or not injury was sustained by persons or property or otherwise; and whether or not loss was sustained from, or arose out of, the results of, the item, or any services that may be provided by ECSS.
Published by: ESA Requirements and Standards Section ESTEC, P.O. Box 299, 2200 AG Noordwijk The Copyright: 2023© by the European Space Agency for the members of ECSS## Change log
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ECSS-E-AS-50-22C
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First issue
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ECSS-E-AS-50-22C Rev.1
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First issue, Revision 1
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Scope
This document identifies the clauses and requirements modified with respect to the standard CCSDS 132.0-B-3, TM Space Data Link Protocol, Issue 3, October 2021, for application in ECSS.
Context information
In the standard CCSDS 132.0-B-3, TM Space Data Link Protocol, CCSDS specifies a data link layer protocol for the efficient transfer of space application data of various types and characteristics over space links.
With this Adoption Notice ECSS is adopting and applying CCSDS 132.0-B-3 with a minimum set of modifications, identified in the present document, to allow for reference and for a consistent integration in the ECSS system of standards.
The TM Transfer Frame specified in CCSDS 132.0-B-3 is similar to the TM Transfer Frame specified in the ECSS standard ECSS-E-ST-50-03C Space data links – Telemetry transfer frame protocol (31 July 2008), that is superseded by the following two Adoption Notices: ECSS-E-AS-50-22 and ECSS-E-AS-50-23 (latest versions).
Differences between these two standards that are not covered by the normative modifications in clause 4 are described in the informative Annex A.
Mapping of superseded ECSS-E-50-xx Standards w.r.t. ECSS Adoption Notice versus CCSDS Standards
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Superseded ECSS
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ECSS Adopted Notice
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Based on CCSDS
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ECSS-E-ST-50-01C
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ECSS-E-AS-50-21
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CCSDS 131.0-B-x
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ECSS-E-ST-50-03C
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ECSS-E-AS-50-22
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CCSDS 132.0-B-x
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ECSS-E-AS-50-23
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CCSDS 732.0-B-x
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ECSS-E-ST-50-04C
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ECSS-E-AS-50-24
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CCSDS 231.0-B-x
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ECSS-E-AS-50-25
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CCSDS 232.0-B-x
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ECSS-E-AS-50-26
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CCSDS 232.1-B-x
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NOTE: The applicable CCSDS Standard referred to by the ECSS Adoption Notice is stated per latest version of the ECSS Adoption Notice.
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Abbreviated terms
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Abbreviation
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Meaning
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AOS
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Advanced Orbiting Systems
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SDLS
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Space Data Link Security
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Application requirements
ECSS-E-AS-50-22_1530001CCSDS 132.0-B-3, TM Space Data Link Protocol, Issue 3, October 2021 shall apply with the following amendments listed in Table 41.
ECSS-E-AS-50-22_1530002Table 41: Applicability table for CCSDS 132.0-B-3
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Clause or requirement number
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Applicability
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Applicable text for ECSS
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Comments
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Text as in the original CCSDS document
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4.1.3.1.7
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New requirement
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The Transfer Frame Secondary Header may be used to provide an extended virtual channel frame count as specified in 4.1.3.4.
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New requirement added: the extended virtual channel frame count added
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4.1.3.4
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New section
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Extended virtual channel frame count
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New section added
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4.1.3.4.1
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New section
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General
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4.1.3.4.2
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New section
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Using the extended virtual channel frame count
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4.1.3.4.2.1
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New requirement
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The length of the Transfer Frame Secondary Header shall be 32 bits.
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4.1.3.4.2.2
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New requirement
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The Transfer Frame Secondary Header Data Field shall contain the 24-bit extension to the virtual channel frame count.
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4.1.3.4.2.3
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New requirement
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The extension to the virtual channel frame count shall be a binary count of the roll-overs of the 8-bit value contained in the Virtual Channel Frame Count in the Transfer Frame Primary Header.
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4.1.3.4.2.4
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New requirement
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The use of the extended virtual channel frame count shall be associated with either a master channel or a virtual channel.
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4.1.3.4.2.5
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New requirement
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The use of the extended virtual channel frame count shall be static in the associated master channel or in the associated virtual channel throughout a mission phase.
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ANNEX(informative)Differences from ECSS-E-ST-50-03C
General
Clause 4 of this document contains normative amendments to CCSDS 132.0-B-3. This Annex describes some additional differences, with respect to the superseded ECSS-E-ST-50-03C Standard, that are not covered by Clause 4.
This Annex lists the differences of technical content, but it is not the purpose of this Annex to provide complete details on each item in the list or to describe the consequences of each item in the list.
Differences
Specification of service interfaces
Section 3 of CCSDS 132.0-B-3 provides a formal abstract specification of a set of service interfaces, including service primitives and parameters, provided by the TM Space Data Link Protocol. There was no equivalent in ECSS-E-ST-50-03.
Specification of protocol procedures
Sections 4.2 and 4.3 of CCSDS 132.0-B-3 specify protocol procedures at the sending and receiving ends. ECSS-E-ST-50-03 specified only the packet processing and extraction functions.
Interfaces for Space Data Link Security (SDLS)
CCSDS 132.0-B-3 specifies the optional interfaces for using the Space Data Link Security (SDLS) and the SDLS Extended Procedures protocols with TM Transfer Frames. For the latter the SDLS Frame Security Report (FSR), which is a new Type-2 Report, is introduced in subsection 4.1.5.5. ECSS-E-ST-50-03 did not include support for interfacing to SDLS. Therefore, this Adoption Notice – unlike the ECSS-E-ST-50-03 - offers to ECSS users the option of using the Space Data Link Security (SDLS) and the SDLS Extended Procedures protocols with TM and AOS Transfer Frames.
Resetting a frame count
A TM Transfer Frame has a Master Channel Frame Count and a Virtual Channel Frame Count. They are 8-bit fields, each containing a sequential binary count (modulo 256). Both standards have requirements about not resetting one of these counts before it reaches 255. In CCSDS 132.0-B-3 the wording is “not … unless it is unavoidable”. In ECSS-E-ST-50-03 the wording was “not … unless there is a major system reset”.
Synchronization Flag and asynchronously inserted data
In CCSDS 132.0-B-3, if the Synchronization Flag is ‘1’ then the frame carries a VCA-SDU: this relates to the formal definition of the Virtual Channel Access Service (see A.2.1 above). ECSS-E-ST-50-03 specified that the Synchronization Flag is ‘1’ whenever the frame does not satisfy the conditions for the flag to be ‘0’. For legacy reasons, ECSS-E-ST-50-03 included the specification of frames with Synchronization Flag ‘1’ to carry asynchronously inserted data.
Managed parameters
Sections 5 and 6.6 of CCSDS 132.0-B-3 have a normative specification of the managed parameters used by the TM Space Data Link Protocol. Annex D of ECSS-E-ST-50-03 had an informative specification, and referred to the parameters as mission configuration parameters.
Protocol Implementation Conformance Statement
Annex A of CCSDS 132.0-B-3 has a normative specification of the Protocol Implementation Conformance Statement (PICS) Requirements List (RL) for an implementation fulfilling the standard. Instructions for PICS generation are given. ECSS-E-ST-50-03 did not include a PICS.
Only Idle Data Frame Randomization
Subsection 4.1.4.6.2 of CCSDS 132.0-B-3 has a normative specification of the Transfer Frame Data Field of the Only Idle Data (OID) Transfer Frame. ECSS-E-ST-50-03 did not include OID Frame Data Field Randomization specification.
Annex D of CCSDS 132.0-B-3 has an informative specification of two possible implementation options of the OID Frame Data Field Randomizer.
Bibliography
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ECSS-E-AS-50-21C Rev.1
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Space engineering - Adoption Notice of CCSDS 131.0-B-4, TM Synchronization and Channel Coding
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ECSS-E-AS-50-22C Rev.1
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Space engineering - Adoption Notice of CCSDS 132.0-B-3, TM Space Data Link Protocol
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ECSS-E-AS-50-23C Rev.1
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Space engineering -Adoption Notice of CCSDS 732.0-B-4, AOS Space Data Link Protocol
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ECSS-E-AS-50-24C Rev.1
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Space engineering - Adoption Notice of CCSDS 231.0-B-4, TC Synchronization and Channel Coding
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ECSS-E-AS-50-25C Rev.1
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Space engineering - Adoption Notice of CCSDS 232.0-B-4, TC Space Data Link Protocol
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ECSS-E-AS-50-26C
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Space engineering - Adoption Notice of CCSDS 232.1-B-2, Communications Operation Procedure-1
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ECSS-E-ST-50-01C
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Space engineering - Space data links - Telemetry synchronization and channel coding
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ECSS-E-ST-50-03C
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Space engineering - Space data links - Telemetry transfer frame protocol
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ECSS-E-ST-50-04C
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Space engineering - Space data links - Telecommand protocols synchronization and channel coding
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