VHiSSI - Very High Speed Serial Interfaces

VHiSSI - Project Overview

Space-based Earth observation and scientific instrumentation currently under development will push the limits of on-board data-handling technology. Several future space-based instruments, for example synthetic aperture radar (SAR) and hyper-spectral imagers, will be capable of producing data at data rates of several Gbits/s.

Telecommunications satellites also have to handle many Gbits/s data on-board. To support the growing demand for on-board communications network bandwidth, ESA has been developing a standard multi-Gbits/s network technology called SpaceFibre. At present this important ESA technology is dependent upon the USA for the radiation-tolerant physical layer devices. USA International Trade in Arms Regulations (ITAR) severely restricts the use of these technologies on European space missions.

The VHiSSI research programme aims to create very high-speed data-interface technology. Levering prior and concurrent research on the emerging ESA SpaceFibre on-board communication standard, it will provide a complete solution for spacecraft on-board data-links and networks. It will provide a non dependent (ITAR free) technology, allowing unrestricted use on European spacecraft and creating substantial export opportunities.

Non space applications expected to benefit from the anticipated technological advancements and resultant European capability include terrestrial avionics, robotics, and automobile networks.

Project Background

Driving Space Applications

Future Earth Observation missions will have increasing demands for high speed interfaces. For example, future synthetic aperture radar (SAR) instruments like HRWS (High Resolution Wide Swath) which generate a large amount of data. HRWS is a demonstrator for typical near future instruments defining the needs for interfaces and other onboard functions like mass-memory systems and downlink bandwidths. The expected total data rate from this instrument is about 14 Gbit/s. The goal of the HRWS study is the conceptual design of an advanced Digital-Beam-Forming (DBF) SAR instrument operating in C-band. This kind of instrument including advanced technologies is to be ready for launch in 2020. A SAR reference instrument which satisfies the system requirements has been defined with ESA (Active Receive-only Digital Frontend for Radar and SAR) and DLR.

Increased demands for high-speed interfaces can be also expected with a view to the next, future downlink communication technologies. There are studies and implementations for data downlink via Ka-Band and by means of laser technology. These technologies will lead to downlink data rates in the area of up to 5 Gbit/s.

These requirements are well beyond the capabilities of SpaceWire and ad hoc solutions are being developed using dependent (ITAR restricted) technologies.

Terrestrial Serial Data-Link Technology

Over the past decade serial data-link technology has become ubiquitous in terrestrial applications. PCI Express is used for device interconnection inside the PC, SATA is used for interconnecting disc drives, Universal Serial Bus (USB) is used to connect local peripherals to a PC, and Gigabit Ethernet is used for internet connection. All of these communication technologies are based on serial communications. While these terrestrial technologies may appear attractive for space applications, they generally have complex protocol stacks that rely heavily on software and complex chip designs. There are no radiation tolerant devices available that support these serial link technologies.

SpaceWire

In parallel with these commercial developments the European space community developed a standard serial data-link specifically designed to meet the demanding requirements of space applications and to be implementable in radiation tolerant chip technology. SpaceWire is a data-handling network for spacecraft which combines simple, low-cost implementation, with high performance and architectural flexibility. Its advantages over competing technologies have been demonstrated by its rapid take up by the normally conservative international space agencies and space industry. SpaceWire is now being used on more than 30 high profile missions and by all of the major space agencies and space industry across the world. SpaceWire is ideal for spacecraft payload data-handling applications up to 200 Mbits/s and can achieve higher data rates by using multiple SpaceWire links in parallel. For data rates above 1 Gbit/s SpaceWire is not an effective solution.

SpaceFibre

SpaceFibre is a very high-speed serial data-link being developed by ESA which is intended for use in data-handling networks for high data-rate payloads. SpaceFibre is able to operate over fibre optic and copper cable and support multi-Gbits/s data-rates. It aims to complement the capabilities of the widely used SpaceWire onboard networking standard: improving the data rate by a factor of at least 10, reducing the cable mass by a factor of four and providing galvanic isolation.

SpaceFibre will support high data-rate payloads, including synthetic aperture radar and hyper-spectral optical instruments. It will provide robust, long distance communications for launcher applications and will support avionics applications with deterministic delivery constraints through the use of virtual channels. SpaceFibre will enable a common onboard infrastructure to be used across many different mission applications resulting in cost reduction and design reusability.

VHiSSI Project

The primary motivation for the VHiSSI project is to provide Europe with important very high-speed serial interface technologies, enhancing the technical capabilities and overall competitiveness of the European space industry, enabling it to compete effectively on the world market.

To achieve these goals technological spin-in from the European microelectronics research community and multi-lateral collaboration between leading European institutions and industry, both large prime contractors and SMEs, has been gathered to provide the necessary breadth of technical knowledge, capability and experience. The VHiSSI consortium brings together partners that each hold a piece of the technological jigsaw puzzle needed to make SpaceFibre-HSSI a reality.

Aims of Research Project

The VHiSSI research programme aims to create very high-speed data-interface technology, suitable for a wide range of demanding space applications where large amounts of data have to be moved rapidly from a sensor to a mass-memory or processing unit, or from the mass-memory to the downlink telemetry unit. This is a critical component technology for future spacecraft payloads, particularly telecommunications and Earth observation payloads where data-rates well in excess of 1 Gbit/s are urgently needed.

The proposed research programme aims not just to solve the pressing problem of high-speed serial interfaces but to provide a complete solution to very high-speed data networking onboard spacecraft, levering research on SpaceFibre using a European fabrication facility, and to provide an ITAR free (non dependent) technology.

The VHiSSI research programme will:

Provide multi-Gbit/s serial data-link technology, essential for future spacecraft onboard data-handling systems.
Lever prior and concurrent research on the emerging ESA SpaceFibre standard, to provide a complete solution for spacecraft onboard data-links and networks, including essential link-initialisation, power management, FDIR, flow-control and QoS.
Provide a versatile chip architecture, which can be adapted and configured to support multiple applications.
Provide the critical clock recovery mechanism that provides high performance on existing European radiation tolerant chip technology with the potential for direct performance gains as device feature sizes shrink.
Use a European semiconductor fabrication facility, enhancing and developing its capabilities for radiation tolerant chip design and production, enabling it to compete in the international space chip market.
Provide a radiation tolerant library for that fabrication facility.
Provide a non-dependent technology (ITAR free), allowing unrestricted use on European spacecraft and substantial export opportunities - an important capability for Europe
Forge a strong partnership between the project partners that will go beyond the proposed research programme to provide a coherent capability for future European high-performance radiation tolerant chip design and manufacture, in support of the European space industry.

The principal focus of the proposed research is very high-speed serial interfaces for future telecommunications and Earth observation with terrestrial avionics, robotics, automobiles and other applications also expected to benefit from the anticipated technological advancements and resultant European capability.

Benefits

The principal benefits of the VHiSSI research programme will be:

Very high-speed serial interface technology which is applicable to many space missions, including large and small satellites, robotic missions, planetary landers and rovers, launchers and related EGSE, and is capable of spin-out to a wide range of terrestrial applications, including demanding robotics applications.
Reliable and radiation-tolerant, high-performance chip due to the application of novel and radiation hard standard cell library optimized for mature 130 nm CMOS process.
Know-how and capabilities, shared by the partners of this research, in the specification, design, manufacture, testing and delivery of mixed signal (analogue and digital) very high speed integrated circuits that are radiation-hardened for use in space.
Mixed-signal high-speed radiation hardened integrated circuits that are free from USA export restrictions (non dependent), that are fabricated and tested in Europe, and that are freely available to members of the European Union and of FP7 for use in space missions.

From the spacecraft prime contractors point of view, SpaceFibre-HSSI will provide:

An essential very high-speed serial data interface technology free of ITAR restrictions (non dependent).
A reduction of the harness and number of interconnections, resulting in improved reliability and lower mass.
A reduction of power consumption by means of a lower number of interfaces and related components.
A simplification of the unit architecture and backplane design.
A simplification of application and network control software, through the integrated QoS services.