National Aeronautics & Space Administration European Space Agency & 1 Modulation and Coding: Draft IOAG Resolutions to CCSDS September 9, 2008 Les Deutsch Jet Propulsion Laboratory, California Institute of Technology Wolfgang Hell European Space Operations Center, European Space Agency Extracted by A. Hooke, 24 Sep 2008

National Aeronautics & Space Administration European Space Agency & 2 Resolution 1: CDMA/DSSS Considering that 1.CDMA/DSSS is commonly used by some agencies for low data rates in an Earth-orbiting data relay system; 2.taking note of relay systems being planned by additional operating agencies, beyond the current NASA, ESA and JAXA; 3.taking into account that the IOAG encourages international collaboration and therefore regards access to such technology on a non-discriminatory basis essential to further interoperability and cross support; the IOAG, resolves that based on the “near-Earth scenario” (missions below GEO orbit) developed by the SISG for the IOAG, urges CCSDS to investigate technical solutions in response to these scenarios and in particular 1.investigate the relevance of the PN spreading and tracking formats in the SNIP agreement material to this purpose; 2.investigate the possibility of development of new DSSS code families; 3.investigate possible procedures for the administration of these new code families.

National Aeronautics & Space Administration European Space Agency & 3 Resolution 2: Bandwidth Efficient Modulation for High Rate Telemetry in Deep Space Applications Considering that to date the only bandwidth efficient modulation scheme endorsed by CCSDS for deep space missions is GMSK; Taking account of envisaged application and mission profiles that suggest that modulation schemes offering hundreds of Mbps may be required in the next decade; the IOAG resolves 1.that IOAG encourages CCSDS to request the Space Link Services area to advance the development of the ‘Mission and Communication Profiles’ report such that pertinent deep space mission needs are identified and quantified; 2.that IOAG suggests that CCSDS puts in place the necessary resources to standardize relevant techniques in response to the projected requirements.

National Aeronautics & Space Administration European Space Agency & 4 Resolution 3: Concurrent High-Rate Telemetry and Ranging Modulation Considering that: 1.IOAG has identified the need for concurrent high rate telemetry and ranging modulation; 2.with the modulation schemes presently recommended for links excluding Earth-orbiting data relay satellites, telemetry with symbol rates above approximately 500 Ksps and ranging are mutually exclusive; 3.solutions currently being studied by two IOAG Member Agencies demonstrate the feasibility of such capability; 4.in the interest of interoperability and cross support a standardized approach is highly desirable; the IOAG resolves that IOAG urges CCSDS to proceed with 1.identifying candidate solutions responding to this operational need for links excluding Earth-orbiting data relay satellites; 2.defining suitable metrics that allow to determine the relative merit of the candidate solutions; 3.developing a standard for concurrent high rate telemetry and ranging based on the solution with the best metrics; 4.developing solutions that are appropriate for Category A & B missions where a single solution that satisfies both is preferred but not required.

National Aeronautics & Space Administration European Space Agency & 5 Resolution 4: New Synchronization and Channel Coding Sublayer Standard Considering that 1.IOAG member agencies have planned multiple near-Earth, Lunar, and deep space missions requiring emergency, proximity, and high-rate telemetry communications links; 2.These links have varied requirements for data rate, latency, bandwidth efficiency, power efficiency, range, codec complexity, and dynamic adaptability; 3.The existing CCSDS recommendations describing the Synchronization and Channel Coding Sublayer of the Data Link layer are inadequate to satisfy all of these requirements; 4.CCSDS has developed a set of mission profiles describing the requirements of the future space missions; 5.IOAG member agencies desire that a new Synchronization and Channel Coding Sublayer standard be completed quickly, to enable these upcoming missions to incorporate it into their designs and implementations in a timely fashion; 6.CCSDS has developed a set of candidate forward error correction coding solutions in the CCSDS O-1 and CCSDS O-2 Orange Books which suitable for "fast track" promotion to Blue Book status; 7.and, it is of common interest to restrict the number of standards to the minimum necessary to enable cross support while minimizing implementation cost; (Continued …)

National Aeronautics & Space Administration European Space Agency & 6 Resolution 4 continued the IOAG resolves 1. To urge CCSDS to recommend appropriate FEC coding solutions meeting the needs of future missions, putting special attention on one or more of the CCSDS Orange books: a.CCSDS O-2 "Low Density Parity Check Codes for Use in Near-Earth and Deep Space;" b.CCSDS O-1 "Flexible Serially Concatenated Convolutional Turbo Codes with Near- Shannon Bound Performance for Telemetry Applications;" and c.CCSDS O-0 (Draft) "DVB-S2 Coding and Modulation Standard Use for High Data Rate TM Links;" as these can offer fast track access to Blue Book status; and verifying the impact on the adjacent Physical and Data Link layers for a homogenous solution. 2. To urge CCSDS to make this recommendation by IOAG-13.

National Aeronautics & Space Administration European Space Agency & 7 Resolution 5: High rate uplink and codes Considering that 1.IOAG member agencies are planning multiple human and robotic near-Earth, Lunar, and deep space missions that will require high data rate uplinks with sustained data rates of Megabits per second and occasional data rates of tens of Megabits per second; 2.These missions are likely to include multinational participation and, as such, will require interoperability and cross-support of telecommunications services; 3.These links need to be power efficient due to limited EIRP, to be highly reliable, to accommodate a wide range of latencies, and to be implementable with limited on-board complexity; 4.Existing CCSDS recommendations for uplink signalling do not provide an adequate solution for such planned links; the IOAG resolves 1.To urge CCSDS to agree with IOAG on a set of requirements for high rate uplink, including commanding, file uploads, and human support applications; 2.To urge CCSDS to identify candidate technical solutions for uplink signaling in response to this set of requirements; 3.To urge CCSDS to rank these solutions according to appropriate figures of merit and make recommendations for new standards to the IOAG by IOAG-13.