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INTEROPERABILITY TESTING OF THE CCSDS FILE DELIVERY PROTOCOL
No full textInternational Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, NevadaThe CCSDS recently developed the CCSDS File Delivery Protocol which can operate in configurations from simple point-to-point space/ground systems to complex arrangements of orbiters, landers, relaying spacecraft, and multiple ground facilities. An international interoperability test program has been developed in support of the development and fielding of the protocol. The first phase was successfully completed in the Fall of 2002. The second phase is to be completed about the time of the presentation of this paper. First phase testing involved five independent implementations of the Core Procedures of the protocol. Since these Procedures are for point-to-point file transfers, only two protocol “entities” were involved in each executed test. The second phase tests other Procedures, which involve multi-hop transferring of files. This phase will involve two separate, independent implementations, with one implementation being hosted on multiple hardware/OS platforms. Each test will involve three or more entities.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection
Performance analysis of CCSDS File Delivery Protocol and erasure coding techniques in deep space environments
No full textThe rising demand for multimedia services even in hazardous environments, such as space missions and military theatres, and the consequent need of proper internetworking technologies have revealed the performance limits experienced by TCP protocol over long-delay and lossy links and highlighted the importance of the communication features provided by the protocol architectures proposed by the Consultative Committee for Space Data Systems (CCSDS). This paper proposes a CCSDS File Delivery Protocol (CFDP) extension, based on the implementation of erasure coding schemes, within the CFDP itself, in order to assure high reliability to the data communication even in presence of very critical conditions, such as hard shadowing, deep-fading periods and intermittent links. Different encoding techniques are considered and various channel conditions, in terms of Bit Error Ratio and bandwidth values, are tested
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TESTING OF A DTN PROTOCOL - CCSDS FILE DELIVERY PROTOCOL INTER-IMPLEMENTATION TESTING FINAL REPORT
No full textInternational Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, CaliforniaThe CCSDS has developed the “CCSDS File Delivery Protocol” (CFDP), as a disruption/delay tolerant file transfer protocol. CFDP allows an automatic, reliable file transfer between spacecraft and ground (in both directions) designed to support the operation of spacecraft by means of file transfer and remote file system management. To support the development and fielding of the protocol in an international and cross-supporting environment, an international, inter-operability test program has been developed and successfully executed. First phase testing involved five independent implementations of the Core Procedures of the protocol. The second phase tests involve multi-hop transferring of files using the Extended Procedures. The third phase involves the testing of the SFO Procedures. The latter two phases involved two independent protocol implementations, namely, those of ESA and JPL. This paper constitutes a final report on the process of testing, the test results, the experience gained, and the resulting plans to extend this methodology to other areas within the CCSDS.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection
Open Source Python Implementation of Ccsds File Delivery Protocol to Support File-Based Operations
No full textThe Consultative Committee for Space Data Systems (CCSDS) File Delivery Protocol (CFDP) enables reliable file transfer across space communication links that experience interruptions and delays, supporting diverse transfer modes with minimal human intervention. This paper presents an open-source Python library implementing CFDP, following guidelines from the CCSDS Blue Book. To date, this library is the only fully functional CFDP implementation in Python and is among the first open-source versions available. Developed in Python 3, with compatibility for MicroPython for low-power applications, the library supports both Class 1 (unreliable) and Class 2 (reliable) file transfers, using Zero Message Queue (ZMQ), CCSDS Space Packet Protocol, and User Datagram Protocol (UDP) for transport and network layers. An extendable virtual file store is included to support various data storage options. Full CCSDS compliance has been validated through cross-testing with the European Space Agency (ESA) CFDP implementation. A graphical user interface (GUI) enhances usability for nontechnical users, supplementing the command-line interface. This open-source CFDP library is ideal for space and terrestrial file transfers and is increasingly valuable for file-based operations in space missions.</p
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Using the CCSDS File Delivery Protocol (CFDP) on the Global Precipitation Measurement mission
No full textInternational Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, CaliforniaThe Consultative Committee for Space Data Systems (CCSDS) developed the CCSDS File Delivery Protocol (CFDP) to provide reliable delivery of files across space links. Space links are typically intermittent, requiring flexibility on the part of CFDP. Some aspects of that flexibility will be highlighted in this paper, which discusses the planned use of CFDP on the Global Precipitation Measurement (GPM) mission. The operational scenario for GPM involves reliable downlink of science data files at a high datarate (approximately 4 megabits per second) over a space link that is not only intermittent, but also one-way most of the time. This paper will describe how that scenario is easily handled by CFDP, despite the fact that reliable delivery requires a feedback loop.International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection
Consultative Committee for Space Data Systems
No full textThis document has been approved for publication by the Management Council of the Consultative Committee for Space Data Systems (CCSDS) and represents the consensus technical agreement of the participating CCSDS Member Agencies. The procedure for review and authorization of CCSDS Recommendations is detailed in the reference [A1], and the record of Agency participation in the authorization of this document can be obtained from the CCSDS Secretariat at the address below. This Recommendation is published and maintained by: CCSDS Secretariat Office of Space Communication (Code M-3) National Aeronautics and Space Administration Washington, DC 20546, USA STATEMENT OF INTENT The Consultative Committee for Space Data Systems (CCSDS) is an organization officially established by the management of member space Agencies. The Committee meets periodically to address data systems problems that are common to all participants, and to formulate sound technical solutions to these problems. Inasmuch as participation in the CCSDS is completely voluntary, the results of Committee actions are termed Recommendations and are not considered binding on any Agency. This Recommendation is issued by, and represents the consensus of, the CCSDS Plenary body. Agency endorsement of this Recommendation is entirely voluntary. Endorsement, however, indicates the following understandings: o Whenever an Agency establishes a CCSDS-related standard, this standard will be in accord with the relevant Recommendation. Establishing such a standard does not preclude other provisions which an Agency may develop. o Whenever an Agency establishes a CCSDS-related standard, the Agency will provide other CCSDS member Agencies with the following information: -- The standard itself. -- Th..
Transferring Files Between the Deep Impact Spacecrafts and the Ground Data System Using the CCSDS File Delivery Protocol (CFDP): A Case Study
No full textThe CCSDS File Delivery Protocol (CFDP) Standard could reshape ground support architectures by enabling applications to communicate over the space link using reliable-symmetric transport services. JPL utilized the CFDP standard to support the Deep Impact Mission. The architecture was based on layering the CFDP applications on top of the CCSDS Space Link Extension Services for data transport from the mission control centers to the ground stations. On July 4, 2005 at 1:52 A.M. EDT, the Deep Impact impactor successfully collided with comet Tempel 1. During the final 48 hours prior to impact, over 300 files were uplinked to the spacecraft, while over 6 thousand files were downlinked from the spacecraft using the CFDP. This paper uses the Deep Impact Mission as a case study in a discussion of the CFDP architecture, Deep Impact Mission requirements, and design for integrating the CFDP into the JPL deep space support services. Issues and recommendations for future missions using CFDP are also provided
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CCSDS FILE DELIVERY PROTOCOL (CFDP) – WHY IT’S USEFUL AND HOW IT WORKS
No full textInternational Telemetering Conference Proceedings / October 20-23, 2003 / Riviera Hotel and Convention Center, Las Vegas, NevadaReliable delivery of data products is often required across space links. For example, a NASA mission will require reliable delivery of images produced by an on-board detector. Many missions have their own (unique) way of accomplishing this, requiring custom software. Many missions also require manual operations (e.g. the telemetry receiver software keeps track of what data is missing, and a person manually inputs the appropriate commands to request retransmissions). The Consultative Committee for Space Data Systems (CCSDS) developed the CCSDS File Delivery Protocol (CFDP) specifically for this situation. CFDP is an international standard communication protocol that provides reliable delivery of data products. It is designed for use across space links. It will work well if run over the widely used CCSDS Telemetry and Telecommand protocols. However, it can be run over any protocol, and will work well as long as the underlying protocol delivers a reasonable portion of the data. The CFDP receiver will autonomously determine what data is missing, and request retransmissions as needed. The CFDP sender will autonomously perform the requested transmissions. When the entire data product is delivered, the CFDP receiver will let the CFDP sender know that the transaction has completed successfully. The result is that custom software becomes standard, and manual operations become autonomous. This paper will consider various ways of achieving reliable file delivery, explain why CFDP is the optimal choice for use over space links, explain how the core protocol works, and give some guidance on how to best utilize CFDP within various mission scenarios. It will also touch on additional features of CFDP, as well as other uses for CFDP (e.g. the loading of on-board memory and tables).International Foundation for TelemeteringProceedings from the International Telemetering Conference are made available by the International Foundation for Telemetering and the University of Arizona Libraries. Visit http://www.telemetry.org/index.php/contact-us if you have questions about items in this collection
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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