1. Systems Architecture WG: Charter and Work Plan
October 23, 2003
Takahiro Yamada, JAXA/ISAS

2. Introduction This presentation reviews:
the charter of the Systems Architecture WG, and
the current status of each work item described in the charter.

3. Goals and Deliverables Defined in the Charter, Draft 4
Define a reference architecture that provides a framework for generation of space data systems standards and development of space data systems.
Document the reference architecture identifying basic elements.
Develop a document that provides to the other Working Groups and BoFs guidelines on how to apply the reference architecture.
Develop formal methods for representing space data systems architectures that will enable sharing of architectural information among engineers.
Develop tools that will facilitate design, modeling, and simulation of system architectural designs.

4. Schedule Defined in the Charter, Draft 4 (1/2)
Date
Milestone
19 May 2003
WG chartered and active.
30 June 2003
Publish a revised version of the reference architecture document (Issue 0.8).
July 2003
Selection of candidate languages and tools.
Prototyping (phase 1) of selected languages and tools starts.
October 2003
WG meeting.
Reports of prototyping (phase 1).
Publish a draft report (Issue 0.1).

5. Schedule Defined in the Charter, Draft 4 (2/2)
Date
Milestone
December 2003
Publish
a revised reference architecture document,
a draft representation method document
a draft tool usage document.
Prototyping (phase 2) starts.
April 2004
WG meeting.
Reports of prototyping (phase 2).
Publish the final version of
the reference architecture document,
the report,
the representation method document,
the tool usage document.

6. Schedule sorted by deliverables
Milestone
Date
Reference Architecture (Standard)
Develop a Reference Architecture
Publish a revised draft
Publish a revised draft (RB)
Publish the final documents (BB)
04/02-06/03
12/03
04/04
Report (Informational)
Publish a draft document (dGB)
Publish the final document (GB)
10/03
Representation Methods (Standard)
with Software Tools
Selection of languages and tools
Prototyping (phase 1)
Publish a draft document (RB)
Prototyping (phase 2)
Publish the final document (BB)
07/03
07/03-10/03
12/03-04/04

7. Items added to the Charter (Draft 5) by Peter
B. GOALS AND DELIVERABLES
Provide a consistent set of views and terminology across all of the other Areas and Working groups. Use existing CCSDS terms where they are clear and unambiguous. Resolve to develop a single agreed approach where there are ambiguous or conflicting uses of terms or definitions.
C. SCHEDULE
In collaboration with at least one other Working Group, develop a domain specific reference architecture and publish the resulting document.

8. Status of the Reference Architecture
The current document is Issue 0.7 released in March, 2003.
In the document, the following five Views are defined, each with its basic constituents.
Enterprise View with Enterprise Objects,
Connectivity View with Nodes and Links,
Functional View with Functional Objects,
Information View with Information Objects,
Communications View with Communications Objects.

9. Issues on the Reference Architecture (1/2)
The Reference Architecture defines basic Objects (e.g., Functional Objects).
However, I do not think it should define sub-classes of Objects (e.g., Mission Planning Functional Objects) because they should be defined in individual architectures. (Some examples should be shown in the Reference Architecture.)
I thought the Reference Architecture should define a set of standard terms to characterize Objects in each View.
For example, the OSI Basic Reference Model defines a set of standard terms to characterize protocols (e.g., connection, relay, multiplexing, sequencing, flow control, etc.).

10. Issues on the Reference Architecture (2/2)
However, my current thinking is that we should publish the document without the definition of standard terms to characterize Objects as the first version because:
Defining such standard terms is not easy, and
The basic architecture should be exposed to CCSDS WG’s as soon as possible.

11. Report (GB) on the Reference Architecture
We should publish a Green Book to show how the Reference Architecture should be used by CCSDS WGs and Agencies.
This GB will:
briefly introduce RASDS (based on the Overview section of the RASDS document),
show the relationship between the Reference Architecture and individual architectures, and
include examples of individual architectures:
Architectures for standards
Architectures for services
Architectures for systems

12. Reference Architecture and Individual Architectures
We can develop multiple architectures, each for a different system or for a different purpose, in a coherent way.

13. Architecture for standards (Example)
This diagram is a fragment of an architecture that shows the relationship among space link protocols.
Onboard End System
Onboard Relay System
Ground Relay System
Ground End System
IPv4
IPv4
IPv4
IPv4
Space
Packet
Space
Packet
Space
Packet
Space
Packet
AOS
Data Link
AOS
Data Link TM
Data Link TM
Data Link TC
Data Link TC
Data Link
RF & Mod
RF & Mod

14. Architecture for Services (Example 1)
This diagram is an example of an architecture that shows services provided by a tracking network.
TLM acquisition service
CMD radiation service
Radiometric data acquisition service
Service management
Tracking Network of an Agency
Supporting Communications Services

15. Architecture for Services (Example 2)
This diagram is an example of an architecture that shows services provided by middleware to applications.
Frame Receive Service
Frame Send Service
Packet Receive Service
Packet Send Service
Publish Service
Subscribe Service
Message Receive Service
Message Send Service
Data Store Service
Data Retrieve Service
Data Catalog Service
Data Discovery Service
On-Line Transfer
Middleware
Messaging
Middleware
Store and
Retrieve
Middleware
Supporting Communications Services

16. Architectures for Systems (Example)
This diagram is an example of an architecture that shows what functions exist at a tracking station and a control center and how they communicate.
Telemetry Acquisition
Data
Analysis
Radiometric
Acquisition
Orbit Determination
Online
Transfer
File
Transfer
Online
Transfer
File
Transfer
TCP/UDP/IP
TCP/UDP/IP
Tracking Station
Control Center

17. Status of the Selection of Languages and Tools
We have not been able to discuss this until now.
We will have a session on this subject tomorrow morning.
My proposal is to develop a Space (Data) System Metamodel based on MOF/UML (But this will be a big task.)