The future of rugged COTS: A 30-supplier OpenVPX ecosystem supports VPX-based systems
A plethora of VPX (VITA 46) specifications prompted the need to develop a framework for system-level interoperability. Hence, OpenVPX interoperability is now in place, and its ecosystem is already maturing with products such as test backplanes, test equipment, and much more. With an experienced group of suppliers offering a variety of OpenVPX compliant technologies, the question is not if a military system designer will initiate a VPX-based application, but when.
VME has been the standard-bearer in rugged COTS military systems for quite some time. Developers have enjoyed unequaled flexibility, thanks to VME’s open architecture, proven reliability, and vast ecosystem. However, today’s systems designers need embedded computing technologies to handle the massive increase of data – as much as 10 times more – to be processed from advanced sensors. System designers also need to integrate enhanced radio communications with radar and other imaging systems powered by high-performance processors and chipsets. VME progeny VPX (VITA 46)-based platforms are the successor in helping designers achieve these goals.
Additionally, OpenVPX (VITA 65) is a major milestone in providing the necessary broad-based system-level-interoperability and resultant ecosystem for the modular serial switched backplane designs enabled by VPX. More than 100 compatible products from more than 30 suppliers are “at the ready” to support VPX-based military systems with a powerful combination of greater performance and lower Size, Weight, and Power (SWaP). This array of new rugged COTS VPX-based technologies has cleared the path for widespread OpenVPX adoption.
Building a sturdy foundation for VPX
VITA working groups have collaborated to secure the viability of the VPX standard by giving it a sturdy foundation. This foundation includes three important specifications: VPX/VITA 46, the board-level base electrical and mechanical standard; VPX-REDI/VITA 48, an enhanced mechanical ruggedization format; and OpenVPX/VITA 65 for system-level VPX interoperability. A major advantage of the board-level specification is that it will allow a steady and competitive ecosystem of connectors and backplanes to emerge. The defense market should realize the same benefits achieved with VME, such as the ability to secure a low-level mechanical and backplane signal interface. Without this secured foundation, it would not have been possible to future-proof VPX platforms.
While it is not expected that customers will start mixing boards from multiple suppliers in their first experience with VPX, OpenVPX is an achievement that will guide all VPX board, backplane, and computer designs from now on. It provides the needed framework for a reliable and continuous technology insertion approach, which is the very the essence of backplane-based computing systems as compared to limited, closed black-box designs. OpenVPX will also allow integrators to design boards to address specific application requirements that they can trust to be compatible with the ecosystem for many years to come.
Elements of a vigorous ecosystem
A healthy OpenVPX ecosystem requires a versatile offering of hardware components that includes backplanes and custom backplanes as well as boards and systems, software and operating systems, design tools, and other elements. Because VPX is based on point-to-point, high-speed links and not a parallel bus, designers need specific backplane routing to implement the most effective computing solution.
On top of the existing OpenVPX profiles that define backplanes slots and boards, a generic set of computer profiles will emerge. These profiles match the most popular application domains, like safety-critical computing, high-performance parallel computing, or embedded SBCs with multiple I/O boards as shown in Figure 1. Within the same computer profile, generic backplanes will become apparent, fostering reuse of the same backplane in multiple designs. Board suppliers such as Kontron are partnering with other suppliers to offer a complete family of generic backplanes.
Hybrid solutions combining legacy VME boards with leading-edge processor cores are also being implemented to meet specific market demand and help guarantee a smooth migration path to OpenVPX. Figure 2 illustrates one migration path option.
Military system designers will most likely evaluate the quality of the VPX technologies based on whether the board supplier also proposes a viable and compatible software road map. With software, there are two main aspects to consider: moving data on the backplane and managing the computer health.
Companies will move data via their preferred data plane serial link technology, and data pipes have been predefined by OpenVPX. The clear winners based on the recent VITA OpenVPX survey appear to be PCI Express (PCIe) and Serial RapidIO, with 10 GbE looming in the not-so-distant future. PCI Express is a plug-and-play, cost-effective hardware approach to data transmission and can be used to build very fast static routing crossbar topologies that are well-adapted to parallel multiprocessing found in many electronic warfare applications. An important consideration is price versus performance. A low hardware price tag is attractive, but may not seem like a deal when engineering resources spend many months trying to implement very complex code at the silicon level to achieve the simplest things such as organizing data flows on the backplane.
In most current VME deployments, health management is handled within low-level application code that is not vendor agnostic. This is why a VITA 46.11 subgroup is working on universal VPX health management that builds on the SMB signals implemented in VPX backplanes. The first successful VPX suppliers to offer a complete solution will likely be the ones who can leverage their experience from other industries such as telecommunications to provide a comprehensive approach to remote computer management. Designers should engage with proven suppliers who can offer software APIs designed for health management for existing applications running on VPX SBCs.
Applying the OpenVPX ecosystem to VPX designs
One of the first VPX benefits to military system designs is the opportunity to reduce size. To date, the physical dimensions of 6U VME-based systems could not take advantage of the reductions achieved from 10 years of silicon process and density advancements. For an application such as an airborne situational awareness system, size also equates to weight, power consumption, and hence mission time. With VPX, very powerful computers can be designed using 3U boards – a significant change thanks to a viable OpenVPX ecosystem.
Payloads in a UAV situational awareness application include video, radar, Electro-Optical/Infrared (EO/IR), and Electronic Countermeasures (ECM), which forces designers to balance performance and SWaP issues. These payloads demand higher-performance processing for differential signal processing. Once again, VPX comes through with higher multi gigabytes per second of data bandwidth at the backplane. Newer radar applications are designed to see finer details, extract tiny bits of information from noise, or detect objects or people at a farther distance. Using VPX for this application satisfies the requirement to move more data within the computer, not just offer more processing power.
For this kind of airborne image application, it is important to select the right components to handle signal processing and to process, exploit, and disseminate large amounts of multisensor data. Interoperability and a multisupplier approach are crucial to achieving SWaP, satisfying aggressive program deployment schedules, and meeting DoD mandates for the use of open standards.
An OpenVPX compatible 3U VPX board is an excellent choice for such an airborne imaging system. A SATA SSD storage solution fits well with this application, as does the integration of an OpenVPX-based XMC interface. This would allow the needed I/O to the backplane – a raw video stream for a high-definition camera can reach 400 MBps – as well as utilizing PCIe connectivity to deliver next-generation radar and full-motion video capabilities. Ground systems can tap into compressed, live video or other information that is easily handled by VPX-based platforms. These platforms provide higher-performance processing per slot and also higher-speed interconnects between processing and I/O elements using PCIe, 10 GbE, or Serial RapidIO. Another benefit of VPX is that it can be used to implement codecs such as ITU-T H.263, H.264 (MPEG-4 part 10) and JPEG2000, efficiently allowing software encoding on general processor boards.
A ruggedized VPX conduction-cooled board with a 0.8-inch pitch is also a good choice in this space-constrained application. Interestingly enough, the results of the recent VITA VPX survey indicate that a significant proportion of VPX planned deployment will be conduction-cooled designs. And, because the technology features of the different ecosystem elements are only part of the equation, interoperability also ensures high availability and reliability for this airborne application.
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