1. Office Name Goddard Space Flight Center 1 Proposed SCaN-Cx Interface Study Approach Dave Israel August 24, 2007

2. Office Name Goddard Space Flight Center 2 Study Subject Fundamental question: “Should the baseline plan for SCaN support of Cx ISS phase include a service interface to the ground stations at the link layer or network layer?” Two basic options for initial Cx support: One uses SLE, one does not. –Out of scope of this initial activity AOS/HDLC discussions Use of IP discussions LDPC Requirements are based on SCaN-Cx MOA and its referenced documents

3. Office Name Goddard Space Flight Center 3 Specific Trade Study Only focus on items that are different between the two options Small team –Bring in technical expertise as needed for testing, demonstrations, or review –Use existing work from other activities for starting points and work with single points of contact for more information –Maintain alignment with CNST, SCIP, SNIS, Standards, and other related activities Provide updates and receive concurrence from SCaN (J. Rush & A. Hooke) and SCIP (R. Miller & J. Hudiburg) throughout the activity

4. Office Name Goddard Space Flight Center 4 Deliverables and Schedule Assumptions used for study Itemized documentation of each option’s ability to meet Cx requirements Performance study results Demonstration of both options performed with GSFC CSTL and JSC Delta cost between two options –Implementation –Operations –Future expansion Documentation of role and responsibility allocation between Cx and SCaN for each option Risk Identification and mitigation strategies List of open issues Pros/Cons/Recommendations Final Report Goal: November 30, 2007

5. Office Name Goddard Space Flight Center 5 Next Steps Collect questions that need to be answered Collect assumptions Start forming teams/connections for different activities Define reference designs for baseline

6. Office Name Goddard Space Flight Center 6 Expected Subjects SLE performance impacts Security implications Service management implications Shift of Roles and Responsibilities Implementation costs Operations costs Future upgrade costs Interoperability considerations Demonstrations and tests including data flows with JSC

7. Office Name Goddard Space Flight Center 7 Discussion Questions Is this an acceptable course of action? What are the schedule drivers?

8. Office Name Goddard Space Flight Center 8 Reference Diagrams

9. Office Name Goddard Space Flight Center 9 SCaN-Cx Interfaces Diagram SCaN Cx Vehicles RF Cx Ground Elements Service Management Data Transfer Tracking & Navigation Cx Ground Element Intercommunications

10. Office Name Goddard Space Flight Center 10 ? ? ? Simplified Option Diagram – Link Layer Interface MS GS AF KSC FDF SN NISN ? SLE

11. Office Name Goddard Space Flight Center 11 ? ? ? Simplified Option Diagram – Network Layer Interface MS GS AF KSC FDF SN NISN ?

12. Office Name Goddard Space Flight Center 12 Direct IP IP over SLE Side by Side Comparison (PHY) (IP Forwarder) (PHY) IP (LNK) End User (App.) UDP IP End User Internal Node (LNK) IP UDP (PHY) (App.) (LNK) (PHY) Control Center Internal Node Control Center AOS IP (IP Forwarder) HDLC (AOS Forwarder) (RF) AOS (RF) AOS Earth Ground Station HDLC SLE (LNK) IP TCP SLE IP TCP (PHY) (IP Forwarder) (PHY) IP (LNK) (App.) UDP IP (LNK) IP UDP (PHY) (App.) (LNK) (PHY) (IP Forwarder) IP (LNK) (PHY) (IP Forwarder) (RF) AOS HDLC AOS HDLC IP

13. Office Name Goddard Space Flight Center 13 Direct IP IP over SLE Cx-SCaN Basic Functional Allocations (PHY) (IP Forwarder) (PHY) IP (LNK) End User (App.) UDP IP End User Internal Node (LNK) IP UDP (PHY) (App.) (LNK) (PHY) Control Center Internal Node Control Center AOS IP (IP Forwarder) HDLC (AOS Forwarder) (RF) AOS (RF) AOS Earth Ground Station HDLC SLE (LNK) IP TCP SLE IP TCP (PHY) (IP Forwarder) (PHY) IP (LNK) (App.) UDP IP (LNK) IP UDP (PHY) (App.) (LNK) (PHY) (IP Forwarder) IP (LNK) (PHY) (IP Forwarder) (RF) AOS HDLC AOS HDLC IP Workstation SLE Gateway Processor RF Router SLE Gateway Router Workstation Router Processor RF Router

14. Office Name Goddard Space Flight Center 14 Common to Both Options RF Modulation and Coding Link layer framing Service Management interfaces Tracking and navigation Time services Line outage recording