Elements of an ICD and a Communication Standard

1. Elements of an ICD and a Communication Standard Feb 7, 2014

2. Standard • Minimal set of specifications to ensure signal compatibility between communications systems • Example contents: clock rates, modulation formats, framing details, etc • Generic • Applicable to wide range of systems • Allows flexibility in key system trades • Aperture sizes, transmit powers, etc. • Excludes details such as power delivery requirements, EIRP, etc.

3. Interface Control Document • Complete specification of optical interface between two specific terminals • Sufficient to allows terminals to be developed and tested independently • Includes details such as power requirements at a common interface between the terminals • Incorporates Standard • Does not specify implementation details

4. Terminal Design Specification • Includes all details of terminal implementation • Incorporates Interface Control Document

5. Terminal Requirements Interface Control Document Standard Terminal Design Specification Terminal Design Specification

6. Categories of Interoperability Requirements • Resource scheduling • Spatial acquisition • Communications • Temporal acquisition (i.e. clock recovery) • Signaling scheme • Data link layer • Interface with other network assets • Host spacecraft, ground networks, RF assets, etc. Subsequent slides will discuss each category with more detailed examples.

7. Resource Scheduling

8. Spatial Acquisition (1)

9. Spatial Acquisition (2)

10. Communications System – Optical

11. Communications System – Optical

12. Communications System – Data Link

13. Criteria for judging standards proposals • Cost of implementation • Re-use of existing infrastructure • Capital vs. operating costs • Cost division (i.e. flight vs. ground) • Competitive vendor base • Performance • Scalability and extensibility • Interaction with other network assets • Architecture