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Replacing the CCSDS Telecommand Protocol with the Next Generation Uplink (NGU)

Show simple item record Kazz, Greg J. Greenberg, Ed Burleigh, Scott C. 2013-01-18T16:38:01Z 2013-01-18T16:38:01Z 2012-06-14
dc.identifier.citation SpaceOps 2012, Stockholm, Sweden, June 11-15, 2012 en_US
dc.identifier.clearanceno 12-2063
dc.description.abstract The current CCSDS Telecommand (TC) Recommendations1-3have essentially been in use since the early 1960s. The purpose of this paper is to propose a successor protocol to TC. The current CCSDS recommendations can only accommodate telecommand rates up to approximately 1 mbit/s. However today’s spacecraft are storehouses for software including software for Field Programmable Gate Arrays (FPGA) which are rapidly replacing unique hardware systems. Changes to flight software occasionally require uplinks to deliver very large volumes of data. In the opposite direction, high rate downlink missions that use acknowledged CCSDS File Delivery Protocol (CFDP)4 will increase the uplink data rate requirements. It is calculated that a 5 mbits/s downlink could saturate a 4 kbits/s uplink with CFDP downlink responses: negative acknowledgements (NAKs), FINISHs, End-of-File (EOF), Acknowledgements (ACKs). Moreover, it is anticipated that uplink rates of 10 to 20 mbits/s will be required to support manned missions. The current TC recommendations cannot meet these new demands. Specifically, they are very tightly coupled to the Bose-Chaudhuri-Hocquenghem (BCH) code in Ref. 2. This protocol requires that an uncorrectable BCH codeword delimit the TC frame and terminate the randomization process. This method greatly limits telecom performance since only the BCH code can support the protocol. More modern techniques such as the CCSDS Low Density Parity Check (LDPC)5 codes can provide a minimum performance gain of up to 6 times higher command data rates as long as sufficient power is available in the data. This paper will describe the proposed protocol format, trade-offs, and advantages offered, along with a discussion of how reliable communications takes place at higher nominal rates. en_US
dc.description.sponsorship NASA/JPL en_US
dc.language.iso en_US en_US
dc.publisher Pasadena, CA : Jet Propulsion Laboratory, National Aeronautics and Space Administration, 2012. en_US
dc.subject Next Generation Uplink en_US
dc.subject Consultative Committee for Space Data Systems (CCSDS) en_US
dc.subject Low Density Parity Check Codes (LDPCC) en_US
dc.title Replacing the CCSDS Telecommand Protocol with the Next Generation Uplink (NGU) en_US
dc.type Preprint en_US
dc.subject.NASATaxonomy Space Communications, Spacecraft Communications, Command and Tracking en_US

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