Restructured Recommendations

The CCSDS has developed several restructured Recommendations for space link protocols. These restructured Recommendations are reorganized versions of the CCSDS Telemetry (TM), Telecommand (TC), and Advanced Orbiting Systems (AOS) specifications, which were originally developed in the 1980s before many of the modern conventions for protocol specification had been formalized. The restructured Recommendations do not change the major technical content of the original Recommendations, but the presentation of the specifications has been changed so that:

  • all CCSDS space link protocols and services can be used to transfer any data over any space link in either direction;
  • all CCSDS space link protocols and services are specified in a unified manner;
  • the layered model matches the Open Systems Interconnection (OSI) Basic Reference Model.
Together with the change in presentation, a few technical specifications have been modified in order to define the Data Link layer protocols in a unified way. Also, some technical terms have been changed in order to unify the terminology used in all the CCSDS Recommendations that define space link protocols and to define them as general communications schemes. Each restructured Recommendation contains an annex that identifies particular changes in terminology.

The restructured Recommendations are expected to supersede the original TM, TC, and AOS Recommendations after a period of acclimation; currently they are being maintained in parallel.

Correspondence of Restructured Specifications with Source Specifications

CCSDS 131.0, TM Synchronization and Channel Coding
  • CCSDS 101.0, Telemetry Channel Coding
CCSDS 132.0, TM Space Data Link Protocol
  • CCSDS 102.0, Packet Telemetry (Transfer Frame)
  • CCSDS 103.0, Packet Telemetry Service Specification (excluding Source Data and Packet Transfer Service)
CCSDS 133.0, Space Packet Protocol
  • CCSDS 102.0, Packet Telemetry (Source Packet)
  • CCSDS 103.0, Packet Telemetry Service Specification (Source Data and Packet Transfer Service)
  • CCSDS 203.0, Telecommand Part 3—Data Management Service
  • CCSDS 701.0, Advanced Orbiting Systems, Networks and Data Links: Architectural Specification (Source Packet)
CCSDS 231.0, TC Synchronization and Channel Coding
  • CCSDS 201.0, Telecommand Part 1 Channel Service
CCSDS 232.0, TC Space Data Link Protocol
  • CCSDS 202.0, Telecommand Part Data Routing Service
CCSDS 232.1, Communications Operation Procedure-1
  • CCSDS 202.1, Telecommand Part 2 Command Operation Procedures
CCSDS 732.0, AOS Space Data Link Protocol
  • CCSDS 701.0, Advanced Orbiting Systems, Networks and Data Links: Architectural Specification (SLS Service and Protocol)

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