1. Standard Onboard interface Services – Overview and status Chris Taylor Stuart Fowell October 09

2. SOIS - main drivers The SOIS set of recommendations are intended to standardise the communication services and protocols used within the flight data handling system. The main motivation for the work is cost reduction: –Provision of requirements for subnetwork services/protocols Standard protocols - less development and test, standardised test equipment Common services regardless of media - less changes in middleware –Standardisation of interfaces to subsystems, payloads and sensor/actuators Reduced vendor costs, opportunity for reusable multi-vendor building blocks Simpler payload integration and multi-Agency interoperability –Standardisation of services to mission application software Insulation from specific hardware and hardware changes Reduced porting costs across missions Opportunity to align with mission operations standards

3. Communication Management Time Access Service File Services Message Transfer Service Device Enumeration Service Packet Service Memory Access Service Synchronisation Service Device Discovery Service Test Service Datalink Extension Protocols Datalink Specific Protocols Application Layer Application Support Layer Transfer Layer Subnetwork Layer Network Protocol Transport Protocol SOIS – layered model CMD & Data Acquisition Services Applications

4. Device Data Pooling Service Device Access Service Device Virtualisation Service Command & data Acquisition Services SOIS C&DA service detail

5. SOIS - Protocols While SOIS CCSDS specifications initially concentrate on services there is also a need to specify protocols that implement the services The SOIS protocol specs are being developed in different ways –Subnetwork protocols are under preparation within the ECSS and SpaceWire working groups –Application support protocols: CMD & Data Acquisition and Enumeration Services will be supported by SOIS and proprietary developed protocols Time Access service will directly interface with a local application File Services will require a device specific access protocol Message Transfer service will adopt the CCSDS Asynchronous Message Service Protocol (last stages of publication)

6. Packet Service Memory Access Service Synchronisation Service Device Discovery Service Test Service Milbus ECSS available Subnetwork Layer SOIS – Subnetwork Protocol Standard CANbus ECSS in progress SpaceWire ECSS planned

7. SOIS input to SM&C discussion

8. Communication Management CMD & Data Acquisition Services Time Access Service File and Packet Store Services Message Transfer Service Device Enumeration Service Packet Service Memory Access Service Synchronisation Service Device Discovery Service Test Service Datalink Extension Protocols Datalink Specific Protocols Applications PUS etc Application Layer Application Support Layer Transfer Layer Subnetwork Layer Network Protocol Transport Protocol CFDP Users CFDP

9. SM&C, PUS AMS, SOIS relationships - Discussion In order for us to proceed in a coordinated way it is necessary to determine how these three standards relate (PUS is not yet adopted by CCSDS so serves here only as an example) SM&C defines a set of mission operations services, it does not define how these should be implemented PUS defines services for command and control, some of which are directly compatible with those defined by SM&C. It also defines a messaging protocol (SM&C message abstraction layer?) and a transport protocol (intimately coupled with the SPP) AMS provides a messaging service and protocol but does not define the contents on the messages (part of the SM&C message abstraction layer?) SOIS defines communication related services across the onboard subnets and application support services that insulate applications from the specifics of the underlying hardware

10. SM&C, PUS and SOIS relationships – Onboard Architecture It us unclear (to me) where the Standard SM&C API resides: –Is it provided BY, or provided TO, the applications implementing the SM&C services? The present architecture (fig 2.3. of the Green book) seems to indicate an API being provided TO the applications This is a crucial point for SOIS as we are not providing mission operations services, rather we provide communication related services in support of mission Applications Assuming that SM&C defines a standard API to be provided by onboard applications, then the mapping of between applications and SOIS is a local matter (although this should also be standardised) The collaboration needed with SOIS is therefore to ensure that the services provided by SOIS are sufficient to support the Applications providing the SM&C services

11. PUS Packets Application Support Layer Services Subnetwork Services File and packet store Command and Data Acquisition Services File Transfer Message Transfer Services Time Access Services File & Packet Store Services SOIS Flight Applications SMC Service 2 SM&C Service N SOIS, PUS, AMS and SM&C – (not 100%) Synchronisation service Test Service Device Discovery Service Memory access service Packet service SOIS Onboard sub-systems Sensors & Actuators Payloads Time Source TM/TC Spacelink SM&C PUS Services Ground Applications Cross Support I/F AMS SM&C service 1 AMS Messages SM&C Compliant API ? CFDP PUS

12. SOIS input to PUS Discussion

13. SOIS - main drivers The SOIS set of recommendations are intended to standardise the communication services and protocols used within the flight data handling system. The main motivation for the work is cost reduction: –Provision of requirements for subnetwork services/protocols Standard protocols - less development and test, standardised test equipment Common services regardless of media - less changes in middleware –Standardisation of interfaces to subsystems, payloads and sensor/actuators Reduced vendor costs, opportunity for reusable multi-vendor building blocks Simpler payload integration and multi-Agency interoperability –Standardisation of services to mission application software Insulation from specific hardware and hardware changes Reduced porting costs across missions Opportunity to align with mission operations standards

14. Communication Management CMD & Data Acquisition Services Time Access Service File and Packet Store Services Message Transfer Service Device Enumeration Service Packet Service Memory Access Service Synchronisation Service Device Discovery Service Test Service Datalink Extension Protocols Datalink Specific Protocols Applications PUS etc Application Layer Application Support Layer Transfer Layer Subnetwork Layer Network Protocol Transport Protocol CFDP Users CFDP

15. SOIS Specification Status (October 09) Subnetwork services –Completed, imminent publication by CCSDS Application support services –Ready for issue as Magenta Books Device Access Service Issue 2 Time Access Service Issue 2 –Ready for 2nd Agency Review File and Packet Store Services Issue 1.4 Message Transfer Service Issue 0.3 –Under Development Device Virtualisation Service Issue 0.1 Device Enumeration Service Issue 0.1 Device Data Pooling Service Issue 2

16. PUS Packets Application Support Layer Services Subnetwork Services File and packet store Command and Data Acquisition Services File Transfer Message Transfer Services Time Access Services File & Packet Store Services SOIS Flight Applications SMC Service 2 SM&C Service N SOIS, PUS, AMS and SM&C – (not 100%) Synchronisation service Test Service Device Discovery Service Memory access service Packet service SOIS Onboard sub-systems Sensors & Actuators Payloads Time Source TM/TC Spacelink SM&C PUS Services Ground Applications Cross Support I/F AMS SM&C service 1 AMS Messages SM&C Compliant API ? CFDP PUS

17. Packet Protocol SOIS subnetwork services SOIS Application support services PUS including File based services Space data link protocols ECSS protocols Onboard datalink Mass memory Protocols

18. Packet Protocol SOIS subnetwork services SOIS Application support services PUS including File based services Space data link protocols ECSS protocols Onboard datalink Mass memory Protocols

20. Ground Utilisation of Packets and File based On-board Services Spacecraft M&C Services On-board Data Management Services File Delivery File Management Packet and Data Link Protocols Packets File Store PFUS SOIS PUS SM&C/PUS CFDP SOIS Space Link Standards

21. Onboard Communications H/W (e.g. MIL-STD-1553B, SpaceWire, CAN RS422) System Services Application BB MTL services PUS library/ TMTC OBCP interpreter Plan/ Autonomy Framework Mission TL/ Mode mgmt Central FDIR AOCS P/L Manager Thermal Power Execution framework OBC Hardware CANRS422 TM/TC Devices Sensors (Star Trackers, Sun sensors, Gyros, Earth sensors, magnetometers) Actuators (Reaction wheels, magneto torquers, thrusters, etc) OBT Mgmt SSMM Mgmt Equipment Mgmt Context Mgmt MIL-1553SpW CPU/ NGmP EEPROM Boot PROM OBTimer SGM HW watchdog BSPHDSW Middleware services Software bus RTOS Security Unit Solid State Mass Memory File Mgt Compress Encrypt Payloads & Instruments SSMM RTU/ Intelligent IO Payload Control Computer SOIS Layers Legacy devices SOIS Application Suppport Layer Subnetwork Layer Standardized devices SOIS Layers ADCs / DACs SOIS Layers Sensor and actuators RAM DSP Digital Sensorbus Payload Data Processing DSP Libraries: Math, Security, Payload,… Reference Architecture and Building Blocks Space Avionics Open Interface Architecture (SAVOIR) SAVOIR Advisory Group : SAG : TEC-EC-ED-SW Nat. Agencies and Industry Networks Storage Compression High Speed Telemetry Encryption SOIS Layers

22. PUS- SOIS discussion In principle PUS and SOIS are complementary: –SOIS provides standard onboard communication related services to assist in harmonising flight implementations and insulating mission applications from specific hardware details –PUS standardises operational services and protocols and may take benefit from the SOIS flight services In practise, there are some overlaps and omissions which will need to be resolved: –The boundary of PUS within the flight system –The capability of the present SOIS to support all PUS services –The way in which file transfer is performed We will also have to take account of the emerging SM&C standards and how they influence both standards

23. Communication Management CMD & Data Acquisition Services Time Access Service File Services Message Transfer Service Device Enumeration Service Packet Service Memory Access Service Synchronisation Service Device Discovery Service Test Service Datalink Extension Protocols Datalink Specific Protocols Applications PUS etc Application Layer Application Support Layer Transfer Layer Subnetwork Layer Network Protocol Transport Protocol CFDP Users CFDP

24. PUS Packets PUS File transfer protocol CFDP Application Support Layer Services Subnetwork Services File and packet store Command and Data Acquisition Services etc. Message Transfer Services Time Access Services File & Packet Store Services SOIS Flight Applications PUS Service 1PUS Service 2PUS Service XPUS Service NPUS Service ------- SOIS, PUS Synchronisation service Test Service Device Discovery Service Memory access service Packet service SOIS Onboard sub-systems Sensors & Actuators Payloads Time Source TM/TC Spacelink PUS Services Ground Applications

25. PUS Packets Application Support Layer Services Subnetwork Services File and packet store Command and Data Acquisition Services File Transfer Message Transfer Services Time Access Services File & Packet Store Services SOIS Flight Applications SMC Service 2 SM&C Service N SOIS, PUS, AMS and SM&C – (not 100%) Synchronisation service Test Service Device Discovery Service Memory access service Packet service SOIS Onboard sub-systems Sensors & Actuators Payloads Time Source TM/TC Spacelink SM&C PUS Services Ground Applications Cross Support I/F AMS SM&C service 1 AMS Messages SM&C Compliant API ? CFDP PUS

26. Agenda for APPs WG

27. SOIS Meeting Objectives Application Services WG(Mon-Friday CF204) –Time Access serviceSubmission for publication –File and Packet Store servicesRID Processing before submission for final Agency review –Message Transfer ServiceRID processing before submission for Agency review –Device Enumeration serviceRid disposition and Update –Device Virtualisation ServiceRid disposition and Update –Device data Pooling Rid disposition and Update –Device Access serviceRid disposition and Update Subnetwork Services WG(No meeting) –All books finished Pending CESG check before publication and WG closure Wireless WG(Mon-Wed Room:Dj124/TB206) –Asset Tracking and ManagementDevelop Magenta first draft –Intra-vehicle communications Initiate Magenta book –Green Book Pending CESG check before publication Area/Joint WG –Plug & Play (Wed/Thu)WG Discussion and proposal for how to proceed –AMS (Tue PM)WG Discussion on possible testing –PUS(Thu PM)SOIS contribution to BOF –SOA(Tue AM)SOIS contribution to BOF –CFDP & DTN (Wed/Thu) WG Discussion 26 October 2009

28. Application support WG Main goals for this week –Finalise text for those books ready for publication (MTS, Time, File services) –These will all need modifying to refer to ISO 7498 and not define ISO definitions inline in the text. Remove MIB where applicable –Decide if file transfer is a service provided by SOIS, decide how it fits with CFDP –Decide how the other service definitions should proceed with or without plug and play –For the plug and play session, we must determine: The scope of the activity deciding what we will and will not cover in SOIS What is needed within this scope and if there are candidates for adoption If there is enough common ground with at least two Agencies in order to proceed If we should raise a separate WG or continue the topic within the APS WG –The more examples we have of how SOIS operates in practice the better. –We must update the Green book to better reflect the latest SOIS approach, identify actions and victims