1. BITTT—Beijing Institute of Tracking and Telecommunications Technology
General design of space internet experiment based on China Space Station project
Peng WAN November 2015

2. Index of Presentation I. Backgrounds
II. Data System of ISS & some experiments
III. Introduction of China Space Station project
IV. General design of space internet experiment
V. Experiment layouts
VI. Some simulation results

3. Part I: Backgrounds

4. Characteristics of Space Station
Space Station is an ideal platform to deal with space internet experiments.
Multi-users
Multi-services
Upgrade-enable
Cross-support
Service-Dynamic
Dynamic data services rely on the inter- network exchange between the experts or equipments on orbit and on ground.
Multi-modules need to communicate with each other through the inner-network.
With various QoS-guarantee space-ground links and astronauts on orbit long-time, the payloads and equipments could be updated or changed easily.

5. Part II. Data System of ISS & some experiments

6. International Space Station
International Space Station (ISS) integrates more than 15 countries’ space technologies, such as United State, Russia, Canada, Japan, etc.

7. Data system of International Space Station
ISS is managed and controlled mainly by the United State’s parts, the responsibility of data system on ISS is not only the transmission of commands, but also the distribution of various experiment data, which is the core part of the whole ISS.
The data system of ISS consists of three layers as follows:
Control the whole ISS, provide interfaces with other modules
Two independent FDDI networks, one for ISS platform, the other for payloads
1: Core Layer
FDDI
The inner network of the ISS’s subsystems
Provide the transmission and process support of local services
2: Local Layer
1553B
Designed for the requirements of each ISS’s payload system
Provide the data acquirement and control services for payload network
3: Application Layer
1553B/CAN

8. Structure of the ISS data system

9. Some space internet experiments on ISS
In recent years, many organizations have made great efforts in the research of space internet technologies, such as:
Laser Communications
Russia : Oct. 2012, ~125Mbps
NASA JPL : OPALS, Jun. 2014, ~50Mbps
Interplanetary Internet : NASA & ESA, 2012, DTN test
Software Defined Radio: NASA, Apr. 2013, SCaN testbed

10. Part III: Introduction of China Space Station project

11. General plan of China Space Station project
~2018: Launch Core module from Wenchang Launch Site, Hainan, China, beginning of the construction of CSS
~2020: Launch Experiment module 1
~2022: Launch Experiment module 2, accomplishment of the construction of CSS
2018~2022: Launch some Manned Spacecrafts & Cargo Vehicles, to provide astronauts & cargos shuttle supports

12. Sketch map of China Space Station structure
Experimental module 1
Core module
Manned Spacecraft
Experimental module 2

13. Data system of China Space Station
The data system of CSS consists of three logically independent networks: Core Network, Local Network and Application Network. Notes: The last two networks are physically in the same Ethernet.
The most important part of the CSS
In charge of the whole CSS’s operation
1: Core Network
1553B
The inner network of the CSS’s subsystem
Provide data processing and delivery support for local units
2: Local Network
Ethernet/Subnetwork 1
Designed for the requirements of CSS’s payload
Provide data delivery support for payload
3: Application Network
Ethernet/Subnetwork 2

14. Integrated Data system of China Space Station project
The whole system consists of such parts: China Space Station, Ground TT&C Station, Data Relay Satellite System, private communication subsystem, Mission Control Center, Science Application Center, etc.

15. Protocol stacks of CSS data system
In China Space Station project, we decide to use the protocol stacks as follows, which is mainly based on the IP over CCSDS AOS.

16. PART IV: General design of space internet experiment

17. 1. Experimental Data System based on CSS project
The space internet experiment plan to add some interesting and useful data units to the CSS project, such as: public internet, security units, satellite communication terminals on CSS platform, etc.

18. 2. Protocol Stacks of Experimental Data System
Space internet experiment based on CSS would carry on multiple protocol stacks, such as:
Standard TCP/IP protocol stack
IP over CCSDS protocol stack, with some new applications
DTN protocol stack, with some new technologies
Gateways might be used in our experiment, to provide the protocol conversion supports.

19. IP over CCSDS Protocol Stack with new applications

20. DTN Protocol Stack with new technologies

21. 3. Protocol conversion examples

22. 4. Applications in the space internet experiment
Space internet experiment based on CSS would carry on multiple application services, such as:
TT&C：Command, Telemetry, etc.
Audio/Video：High definition video, high quality audio, etc.
Interactive Internet：Instant Communication, File Transfer, HTTP, SMTP, SNMP, Multimedia services, etc.
Science：Tele-operation, Science data transmission, etc.
The general design of the data system in the space internet experiment should satisfy the basic QoS requirements of each application services.

23. PART V : Experiment layouts

24. Suggestion of some space internet experiments
With the CSS as the test platform, we plan to arrange such space internet experiments as follows:
Data exchange technologies based on DTN in LEO missions
Mobile Access & Lossless Handover technologies in LEO missions
Space-Ground-in-One all-IP Inter-Networking technologies
Space-Ground-in-One Network Management technologies
Multi-services Quality of Service guarantee technologies
Welcome to join such project with great ideas and plans.

25. 1. Data exchange technologies based on DTN in LEO missions
Purpose:
Scene:
Test 1: TC&TM performance based on DTN
Test 2: Science data transport performance based on DTN
Test 3: New DTN technologies in LEO missions

26. 2. Mobile Access & Lossless Handover technologies in LEO missions
Purpose:
Scene:
Test 1: Schemes on movement prediction
Test 2: Schemes on non-movement prediction for large coverage & high dynamic target

27. 3. Space-Ground-in-One all-IP Inter-Networking technologies
Purpose:
Scene:
Test 1: Schemes for mobile IP
Test 2: Schemes for IP routing under “LEO-GEO” satellite constellation

28. 4. Space-Ground-in-One Network Management technologies
Purpose:
Scene:
Test: Management schemes and interfaces between different units for the Space-Ground-in-One Network

29. 5. Multi-services Quality of Service guarantee technologies
Purpose:
Scene:
Test 1 : “IP+VC” cross-layer QoS schemes based on genetic algorithm
Test 2 : Adaptive Coding & Modulation schemes for the QoS improvement

30. PART VI : Some simulation results

31. 1. Simulation Scene

32. 2. Proto-type test platform in lab
Test equipment
Service simulator
Ground Gateway simulator
Wireless Links simulator
Space Gateway simulator

33. 3. Performance Simulation of our new technologies
(1) Hybrid Multi-Copy Routing (HMCR)

34. 3. Performance Simulation of our new technologies
(2) Network Coding CGR (NC-CGR)

35. 3. Performance Simulation of our new technologies
(3) Network Coding LTP (NC-LTP (version 1))

36. 3. Performance Simulation of our new technologies
(4) Hiberarchy- SNMP (H-SNMP)

37. Thanks.