Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
SISG IOAG Space Internetworking Strategy Group CNES DLR ESA JAXA NASA Report to the second Inter-Operability Plenary (IOP-2) Space Internetworking: a recommended strategy for future international interoperability IOP-2 @ Geneva 09 December 2008 The Evolution of International Cross Support IOP-1 (June 1999) International commitment to point-to-point cross support Mission recovery Ad-hoc Mars cross support Significant International partnering IOP-2 (December 2008) Proposed: international commitment to end-to-end, networked cross support the “Solar System Internetwork” 2 Interoperability and Cross Support A B INTEROPERABILITY: the technical capability of two or more systems or components to exchange information and to use the information that has been exchanged Spacecraft A Ground Station B Control Center A Cross Support Partner CROSS SUPPORT: an agreement between two or more organizations to exploit the technical capability of interoperability for mutual advantage, such as one organization offering support services to another in order to enhance or enable some aspect of a space mission 3 Resolution from IOAG-11 June 2007 The IOAG resolves to form a Space Internetworking Strategy Group to reach international consensus on a recommended approach for transitioning the participating agencies towards a future “network centric” era of space mission operations. The group will focus on the extension of internetworked services across the Solar System, including multi-hop data transfer to and from remote space locations and local networked data interchange within and among the space end systems. 4 Space Internetworking Strategy Group (SISG): Process The SISG was staffed by technical experts appointed by the IOAG agencies CNES DLR ESA JAXA NASA The group met four times in plenary session (October 2007, March 2008, May 2008, September 2008) and during the final phase held biweekly videoconferences The group’s consensus recommendations were reported to IOAG-12, September 2008 Characterization of interoperability today Near Earth Earth Projection of interoperability 2015-2030 Moon Mission Scenarios Mars Identification of need for Internetworking Definition of an Internetworking architectural concept Deep Space Analysis of candidate technologies Recommendation: change goals and roadmap 5 Characterization of International Cross Support ~2008 Current international crosssupport is primarily: CCSDS-SLE forward & return frame relaying • Bilateral • • • • Ground-based (CCSDS ‘SLE’) Point-to-point (based on CCSDS frames) Relatively simple and static Manually configured CCSDS long-haul protocols A B Capable ground-based cross support A B A A Missionspecific relaying CCSDS-SLE forward & return frame relaying A There is no international agreement or common framework for in-space cross support or end-toend data exchange Missionspecific relaying CCSDS long-haul protocols CCSDS proximity protocol A B B B Rudimentary data relay capability at Mars A B B B A 6 Scenario for International Cross Support ~ 2015 - 2020 Next step in cross support: • Existing point-to-point SLE cross support maintained and generalized into Cross Support Transfer Services (CSTS) and Cross Support Service Management (CSSM) • Basic CSTS/CSSM services deployed and partial automation in place: • CFDP for file transfer • Packet-based relaying • Encapsulation for IP and DTN • Related Navigation, Timing, EDL CCSDS EDL CCSDS CSTS-based end-end data transfer and timing CCSDS CSTS-based ground relaying and tracking A B A Standard CCSDS in-space relaying B B B A A Upgraded in-space cross support via data relays A • In-space cross support formalized, CCSDS CSTS-based end-end data transfer and timing e.g., on data relays Extend international cross support agreements into space and develop new end-toend data exchange services B B B A A A B A 7 Scenario for International Cross Support ~ 2025+ Future scenarios (e.g., ILN, ISECG) indicate that international crosssupport will grow to become: CCSDS end-end space networking C B A A C C • Multilateral • Both space and ground-based • A mix of point-to-point and multipoint-to-multipoint • More complex and dynamic • More highly automated B B B \\\ C CCSDS end-end space networking A A A C CCSDS surface networks C C Emphasis on fullystandardized end-to-end networked data transfer CCSDS crosslinks Extensive in-space cross support via data relays and planetary surface communications B B A B C A B A A C 8 Networked Communications SCHEDULED Currently, end-to-end connectivity is configured manually by scheduling contacts. Humans predefine static routes and manually manage the end-to-end data flow Actual C C B B A B C A B A A C manual route reconfiguration With a networked approach, the networking protocol automatically makes the best routing decision - selecting the appropriate connections based on schedule information C C B B A B C A B A operator resources are focused on mission results, not on data management A C 9 Evolution of Terrestrial Networking 10 Networking The Terrestrial Internet 1969 1971 • • • • • Global “network of networks” (millions). Based on IP "packet switching“ technology Commercial, cheap, well-tested Automated routing – low ops cost, resilient Internet packets are routed from network to network and delivered to the destination in real time. • If a route cannot be found, these packets are discarded. • Assumes continuous connectivity, low latency 19602000 2000 2008 1982 The Space Internet 1987 Today • Uses commercial technology where possible • IP can be used only if there is a continuous, low latency end-to-end data connection; otherwise, the emerging Disruption Tolerant Networking (DTN) technology must be employed • DTN doesn’t depend on continuous connection: instead, each network node keeps “custody” of the data as needed until it can be transferred. • DTN uses a “store-and-forward” technique – information does not get lost when there is no immediate path to the destination. • Automated routing reduces manual setup of data paths, speeds failure recovery (by rerouting) 2015 2025 11 Notional Roadmap: Solar System Internet Infusion into international cooperative missions Phased mission support infrastructure upgrades SSI capability development 2008 2009 2010 2011 2012 ~2013 ~2015 ~2025 SISG SSI Strategy SIAG SSI Architecture CCSDS End to End and In-Space services CFDP Space Packet Relay Encapsulation DTN and IP suites Related Navigation, Timing, EDL protocols Initial IP + DTN operational demonstrations on ISS Early Lunar Network (ILN) + Upgraded Mars Network Mature Lunar Network + Initial Mars Network (Mars Sample Return) 12 Recommendations of the Strategy Group 1. IOP-2 agencies should endorse the IOAG’s plans to embark on a significant new international initiative to establish the vision and architectural framework for a Solar System Internetwork (SSI) 2. Space Internetworking Architecture Group (SIAG) should formalize a draft SSI Architectural Definition by October 2009 CCSDS agencies should begin developing the necessary suite of space internetworking standards 3. Standard in-space and end-to-end cross support services. Target completion date of 2012 to support early ILN IOP-2 Agencies should nominate representatives from their programs and projects to work with the SIAG to identify potential missions which may take benefit from adoption of the SSI related standards, leading to a gradual build up of SSI compatible in-space and ground-based infrastructure 4. Earth Network, Lunar Network and Mars Network Another IOP should be convened in <5 years to review progress 13 SSI Solar System Internetwork IOAG Space Internetworking Strategy Group: Process and Findings 14 Background: Evolution of Space Internetworking Simple routing of Space Packets over TM/TC Adopted as the ISS baseline in 1989: early networked operations 1. Packet TM/TC 2. Advanced Orbiting Systems (AOS) Adaptation of the “TCP/IP” stack for use near-Earth 3. IP-based SCPS Extension of TM/TC to short range orbiter-relay environments (Prox-1 protocol) and to ground network cross support (via SLE) Automated file transfer over TM/TC/AOS/Prox-1. 5. CFDP IP for real-time, short delay, connected environments. DTN custodial, store and forward routing for disconnected environments 1980s 4. Proximity-1 & SLE 1990s 6. IP & DTN 2000s 15 Projection of Cross Support: 2015-2030 Three sets of mission scenarios were analyzed: Earth Orbiting missions Moon Exploration Mars Exploration • Mars is representative of other deep space missions Four clear common trends were discerned: Increasing reliance on international cross support -- a missionenabling capability • • Increasing dependency on data relays • • Founded in spectrum allocation Shifting from spectrum non-interference to spectrum-sharing Bent pipe below GEO, store and forward otherwise Store and forward relays will evolve to become routing nodes on a network Higher forward and return data rates Shift towards networked operations • Mix of multiple data types, with different service properties and multiple sources and destinations, sharing a common data communications infrastructure. 16 Lunar + Mars Scenario: 2010-2030 Agency “B” Science Orbiter Agency “A” Ground Site Agency “C” Rover Agency “B” Rover Agency “A” Science Orbiter (Store/Forward) Moon c. 2010 Mars c. 2020 Agency “B” Rover Agency “B” Ground Site Agency “B” Science Orbiter Agency “A” Science Orbiter Agency “C” Rover Moon c. 2020 Mars c. 2030 Manned Rover Agency “A” Rover Agency “A” Ground Site DTE/DFE Proximity Surface WLAN “B” Agency “A” Comm Relay Human Habitat Agency “B” Rover “C” 17 Earth Orbiting (Robotic) Scenario: 2015-2030 Agency “B” Science Orbiter Agency “B” Ground Site Agency “C” Ground Site Agency “C” Science Orbiter Agency “A” Science Orbiters Agency “A” Ground Site Earth Science Today Only Ground Cross-support Earth Science 2030 The Sensor Web Era Correlates spacecraft, surface sensors Rapid, automated response to alerts Enabled by automated routing across the spacecraft RF links Multiple Agencies Multiple Assets Internetworked 18 The Trend Towards Internetworking: 2015-2030 The complexity of the communications topology required by future missions cannot possibly be supported by manually- configured connectivity International cross support requires a long-term space communications architecture that: Drives the space community towards the need for automated routing and networking Shifts the data communications paradigm from simple point-to-point links towards a network of nodes provided and operated by different organizations Is engineered to match the unique space environment (which may include frequent disconnections, long delays, simplex links and possibly non-contemporaneous end-to-end connectivity) Supports a smooth evolution towards a fully internetworked configuration The IOAG recommends that the space community should start a bold new initiative: to establish the vision and architectural framework for a Solar System Internetwork 19 Conceptual SSI Architecture Elements: Agencies Rovers Surface relays Orbital relays Control Center Control Center GEO / Direct Comm Mission LEO/MEO Earth Orbit Inter-Network Lunar Orbit And Surface Inter-Network Mars Orbit And Surface Inter-Network Control Center 20 The Solar System Internetwork Provides networked data communications across the Solar System Secure, reliable, robust, end-to-end, packet based A confederation of independent, cooperative infrastructure assets Autonomously owned and operated by diverse space mission organizations Provides common, cross-supported network services for the benefit of all participants Terrestrial: ground stations, control facilities, ground data networks, etc. In space: data relays, surface communications networks, collaborative space mission elements, etc. Bound together by: Statements of Intent from individual organizations to contribute infrastructure capabilities in order to support an internetworked data flow for individual missions. Subject to bilateral or multilateral cross support agreements Standards: An agreed set of common, extensible interoperability standards Cross Support Services: An agreed and published catalog of commonly provided cross-support services - in space and on Earth – that are offered by individual agencies Management Processes: An agreed set of cross-support service management processes, mechanisms and capabilities (in space and on Earth) that allow internetworked data flow to be invoked and configured Governance mechanisms to administer the necessary core internetworking management, coordination and operations functions that enable end-to-end internetworked data communications. 21 Internetworking protocols for the SSI Three internetworking protocols to support the SSI architecture have been identified. Space Packet • Internet Protocol (IP) • Continued support of conventional space missions, with fairly static connectivity To support flexible, automated routing in short-delay space mission environments with continuous endto-end connections Delay and Disruption Tolerant Networking (DTN) • To support flexible, automated routing in variable delay space mission environments with no expectation of a continuous end-to-end data path CCSDS has defined a robust Encapsulation mechanism which allows all three of these Network layers to co-exist and be cross-supported without perturbing current space Link architectures and cross-support interfaces Fully evolutionary approach that preserves and respects prior agency investments Allows different protocols to be applied to different missions to accommodate changing requirements Space Applications (CFDP, etc.) DTN Space Packet Internet Protocol (IPv4/IPv6) CCSDS Encapsulation CCSDS Link – AOS, TM, TC, Prox-1 22 Governance Process A multi-agency governance process will be needed to transition to the space internetworking era The internetwork contains a variety of client and service nodes owned and operated by multiple agencies. Governance is anticipated to be more coordination than control Governance examples: Address space assignments and allocations Mechanisms for creating service agreements and for coordinating resource scheduling and priorities Governance will evolve, starting with some minimal governance during the nascent stage and ramping up when the internetwork matures. 23 Finis 24