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

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

Part I: Backgrounds

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.

Part II. Data System of ISS & some experiments

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

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

Structure of the ISS data system

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

Part III: Introduction of China Space Station project

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

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

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

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.

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.

PART IV: General design of space internet experiment

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.

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.

IP over CCSDS Protocol Stack with new applications

DTN Protocol Stack with new technologies

3. Protocol conversion examples

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.

PART V : Experiment layouts

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.

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

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

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

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

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

PART VI : Some simulation results

1. Simulation Scene

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

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

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

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

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

Thanks.