deLL: Background experience in spacecraft protocols

Background experience in spacecraft protocols

We have long, in-depth experience of the development, testing and review processes for the international standards and recommendations for spacecraft protocols for CCSDS (Consultative Committee for Space Data Systems), ESA and ECSS (European Cooperation for Space Standardization).

CCSDS and ESA standards from 1986 to the present

We continue to contribute to the updates and reviews of CCSDS recommended standards for space telemetry and telecommand data links and protocols. Recent subjects have included Proximity-1, IP-over-CCSDS and frame-level security.

We were involved in the development of the CCSDS and ESA telecommand standards from 1986, beginning with a study for ESA of the COP-1 automatic retransmission protocol in the Transfer Layer. The study included:

production of a rigorous and unambiguous Formal Description of COP-1
development of a detailed simulator to check its operation

The Formal Description resulting from the study formed part of the CCSDS and ESA standards documents. We have subsequently performed many other related studies for ESA and have presented papers at industry conferences.

ECSS Standards for Telemetry and Telecommand Space Data Links, 2002-2008

From 2002 we provided support for the development of ECSS telemetry and telecommand standards, and the related handbook, in the E-50 Space Engineering - Communications discipline:

ECSS-E-ST-50-01C - Space data links - Telemetry synchronization and channel coding
ECSS-E-ST-50-03C - Space data links - Telemetry transfer frame protocol
ECSS-E-ST-50-04C - Space data links - Telecommand protocols, synchronization and channel coding
ECSS-E-HB-50A - Communications guidelines

COP-1 review in 2001

In 2001, we performed a validation study for ESA of changes to COP-1, the Transfer Layer protocol of Packet Telecommand. The revised version is called COP-1B. The validation included:

tests to check the behaviour of the complete COP-1B State Tables
tests to check the changes

The study demonstrated the need for an additional amendment and provided useful background information for input to the CCSDS panel. COP-1B was formally accepted by CCSDS in May 2001.

CFDP review in 2000

We performed a study for ESA in 2000 to review the new CCSDS File Delivery Protocol (CFDP). As part of the study we simulated the operation of CFDP over Packet Telecommand and Telemetry links.