ISO 22664:2016

Overview

ISO 22664:2016 - "Space data and information transfer systems - TC (telecommand) space data link protocol" - specifies the TC Space Data Link Protocol originally developed by the Consultative Committee for Space Data Systems (CCSDS). The standard defines the services, protocol data units (PDUs) and procedures that govern telecommand (TC) data transfer between ground and space systems. It is intended to enable interoperable, cross-supported mission links but deliberately does not mandate specific product implementations, interface implementations, technologies, or management procedures.

Keywords: ISO 22664:2016, TC space data link protocol, telecommand, CCSDS, space data link.

Key topics and technical requirements

ISO 22664:2016 covers the protocol architecture and operational behavior; major technical topics include:

• Service definitions - services provided to users such as MAP (Multiplexer Access Point) packet service, virtual channel packet service, access and frame services, and command operation packet (COP) management.
• Protocol Data Units (PDUs) - structure and semantics of the TC Transfer Frame, Communications Link Control Word (CLCW) and segment headers used for framing telecommands.
• Protocol procedures - sending-end and receiving-end procedures for packet processing, multiplexing, framing, decoding and error/status handling.
• Managed parameters - configuration parameters for physical channels, master channels, virtual channels and MAP channels (documented in a dedicated section).
• SDLS (Space Data Link Security) option - optional security-related protocol behavior and additional managed parameters to support the Space Data Link Security Protocol.
• Abstract models and functional decomposition - logical diagrams and functional models that guide implementation without prescribing hardware or software solutions.

The standard is organized into sections for overview, service definition, protocol specification (with and without SDLS), and managed parameters plus informative annexes.

Practical applications

ISO 22664:2016 is used to:

• Define telecommand link behavior in spacecraft and ground-station data-link systems.
• Ensure interoperability between agencies and contractors for cross-support missions.
• Provide a reference for implementing TC framing, multiplexing and link-control mechanisms.
• Incorporate security options (SDLS) into TC links where required.

Typical implementations include flight software, ground-segment link controllers, mission control systems and space-ground interface components.

Who should use this standard

• Spacecraft systems engineers and avionics designers
• Ground-segment and mission operations developers
• Satellite integrators and contractors working on cross-support missions
• Architects implementing secure telecommand links (SDLS)
• Standards and interoperability teams at space agencies and commercial space companies

Related standards and sources

• CCSDS Recommended Standards (origin of ISO 22664:2016, CCSDS 232.0-B-3)
• Space Data Link Security Protocol (SDLS) referenced within the document

For the full normative text and implementation details consult ISO (iso.org) and CCSDS (ccsds.org).