Traditionally, military electronics have been extremely expensive, usually purpose-designed, and uniquely built for each application. Systems often do not communicate with each other, making future net centric warfare difficult. Reuse of hardware and software has been the exception rather than the norm, and design cycles historically have been long and expensive.
Militaries are now moving towards open system design. An open systems design is a design approach for developing an affordable and adaptable open system. An open system is a system that employs modular design tenets, uses widely supported and consensus-based standards for its key Interfaces, and is subject to Validation and Verification, including Test and Evaluation, to ensure the openness of its key interfaces.
The use of open standards with a competitive supply chain can reduce cost and risk and accelerate products and solutions to markets. Without them, new platforms will be too expensive to procure and capability will make its way to the warfighter much too slowly to be useful at all against an ever-more-sophisticated adversary.
Wilson said the services see the open systems approach as critical to their continued emphasis on the concept of multi-domain operations. “Let me give you an example: the Air Force operates 80 satellites. Some of them provide communications, some of them do missile warnings. So an Air Force satellite detects and locates operations on the ground, that information can be sent directly to forces in the field a Navy ship or an Army battalion can that can direct fires and destroy things. Any sensor, any shooter. That’s where we want to get to,” she said. “It’s linking up in near-real-time, space, air, manned, unmanned, ground, and sea, so that when we detect a problem, everybody knows about it and the fires are directed to be able to overwhelm an enemy before they even know what’s going on.”
“We need an open mission systems architecture so that everybody has standards for communications and everybody knows what the other standards are,” Air Force Secretary Heather Wilson told an audience on Feb. 2019 at the Center for Strategic and International Studies. “We need to have the ability for any sensor to connect to any shooter at machine-to-machine speed. The ability to know what those standards are and that all of our equipment will be done that way in all three services — that’s a very big deal.”
A key to the design of open systems is the use of open standards. Open standards have driven open architectures in military systems, whether they are using commercial off-the-shelf (COTS) products or not. Whether on the ground, at sea, or in the air, military systems like monitors, sensors, and radios are filled with small-form-factor embedded computing technologies.
One of the earliest open standard embraced for military applications was the VME bus, that was first published more than 20 years ago. The original version of VME created in the 1980s, which eventually was standardized as IEEE 1014-1987, called for both 3U and 6U form factors. The 3U format was popular initially because there were enough pins on the single 96-pin P1 connector to support the popular 16-bit microprocessors of the era, and the board size was similar to contemporary standards such as STDbus, Multibus II (single), S-100, and others. However, over time the 3U VME format fell mostly out of favor as address and data bus widths increased, calling for more pins on the backplane. As 32-bit processors became the norm, the 6U format with both P1 and P2 connectors became the de facto size of choice for VME, dominating market offerings. As manufacturers embraced 6U VME more and more, they also realized the benefits of increased real estate for integrating more features on a single board, and created densely packed designs.
At first glance, a 3U board would appear to be half the size of a 6U board. Viewed from the front panel, this is very true: A 3U front panel is 132 mm long, while a 6U front panel is 265 mm long, and both are the same width. Based on this, it seems logical that a 3U board can contain 50 percent of the functionality of a 6U board. The outline of a 3U printed circuit card is 100 x 160 mm, but with the keep-outs required for the connectors and conduction cooling wedgelocks, the “useful” area is approximately 78 x 148 mm, or 11,544 mm2. The same considerations applied to a 6U outline of 233 x 160 mm result in a useful area of 211 x 148 mm, or 31,228 mm2. With this reasoning, the mathematical ratio of available real estate on 3U compared to 6U is only 37 percent – not nearly half. Thus, a system that could be implemented with three 6U boards would take as many as nine 3U boards.
Two PCI Industrial Computer Manufacturers Group (PICMG) standards, PICMG 1.0 (PCI-ISA Passive Backplane, 1994) and PICMG 2.0 (CompactPCI, 1995), were released 11 and 10 years ago respectively, and are used for a variety of military applications worldwide. Companies such as BES Systems Ltd. in Israel offer a complete range of ruggedized airborne, vehicle, and naval computers compliant to the PICMG 1.1 specification, additionally providing compliance to military standards including MIL-STD-810E, which dictates tough requirements for shock, vibration, humidity, fungus, salt and dust, and fog. This means that the 3U systems consume 150 percent of the total volume to deliver the same functional real estate for circuitry as an equivalent 6U system. This should cause many system designers to seriously consider a 6U solution when they thought they would be better off with 3U.
Released in 1995, the CompactPCI standard was developed for ruggedized industrial applications. It offered then state-of-the-art performance, based on ubiquitous PCI silicon available from virtually every microprocessor and peripheral chip manufacturer. It was based on the same IEEE 1101.1 mechanical standard used by VME, and it became very popular for communications applications worldwide. Specially ruggedized 3U CompactPCI products are being used for a wide variety of airborne, vehicle, and even space-based systems. One example is the AVC-CPCI 3009 system offered by SBS Technologies, developed for Unmanned Aerial Vehicle (UAV) applications . Its integrated frame grabber and MPEG-4 image compressor connect directly to the airframe’s onboard camera, forwarding data in real time to warplanners on the ground. Systems are also going into space. Aitech’s S950 3U CompactPCI SBC is conduction-cooled and offers a PowerPC 750FX CPU . It is rated to operate in Low Earth Orbit, Geosynchrounous Orbit, and Mars Terrestrial environments.
As developers continue to ask for higher performance and functional density, the need for a 3U format hasn’t gone away. This is especially true in light of considerations such as Size, Weight, and Power (SWaP). Given the examples where 3U formats have proven viable, the architects of VME specifications have likewise stepped back to reevaluate a 3U format for their technology. Serial interconnects are now to the point where speed, reliability, and robustness make them a viable option for board-to-board interconnect. By eliminating the parallel bus constraint – and defining an interconnect scheme leveraging new serial technologies such as Serial RapidIO, Ethernet, and PCI Express – pins can be freed up to support the right mix of data and control plane pins without sacrificing board-to-board bandwidth.
The 6U CompactPCI systems are also being used for military applications. Performance Technologies, Inc. builds a sophisticated Mission LAN System using the PICMG 2.16 CompactPCI Packet Switched Backplane standard. Intended to be part of a National Command Center aboard a heavily modified Boeing 707 aircraft known as the TACAMO, it maintains communication and control in the event that other command centers are damaged or destroyed. It provides networking and routing within the aircraft, handling packetized radio, satellite, radar, and laser transmissions, and ties together different systems on the plane
Much of today’s open-systems military embedded computing systems rely on OpenVPX standards of the VITA open standards, open markets trade association in Oklahoma City. Yet OpenVPX has allowed a proliferation of standards that can cause confusion rather than guidance. In fact, Littlefield calls only a qualified success. Yet the emerging SOSA standard has the potential to sharpen the OpenVPX standards such that these standards promote true interoperability among third-party suppliers, help prevent vendor lock, and affordable systems development in a relatively short period of time.
The US military is now making a new push for modular, open systems, with the secretaries of three military services have signed a joint memo telling their acquisition officials to align their programs around a common set of data interchange standards. The Army, Navy, and Air Force are directed to include Modular Open Systems (MOSA) standards in all requirements, programming, and development activities for future weapon-system modifications and new-start development programs to the furthest extent possible.
A key to the design of open systems is the use of open standards. The DoD Information Technology Standards Registry (DITSR) mandates the minimum set of standards and guidelines for the acquisition of all DoD systems that produce, use, or exchange information. Programs should design their system based on adherence to the following five (5) MOSA principles:
1. Establish an Enabling Environment:
Program Manager (PM) establishes supportive requirements, business practices, and technology development, acquisition, test and evaluation, and product support strategies needed for effective development of open systems.
2. Employ Modular Design:
Effective modular design is contingent upon adherence to four major modular design tenets:
- Cohesive (contain well-focused and well-defined functionality)
- Encapsulated (hide the internal workings of a module’s behavior and its data)
- Self-contained (do not constrain other modules)
- Highly binned (use broad modular definitions to enable commonality and reuse)
3. Designate Key Interfaces:
Interfaces should be group into key and non-key interfaces. Such distinction enables designers and configuration managers to distinguish among interfaces that exist between technologically stable and volatile modules, between highly reliable and more frequently failing modules, between modules that are essential for net-centricity and those that do not perform net-centric functions, and between modules that pass vital interoperability information and those with least interoperability impact.
4. Use Open Standards:
Interface standards should be well defined, mature, widely used, and readily available. The memo — titled “Modular Open Systems Approaches for our Weapon Systems is a Warfighting Imperative” — calls out existing and emerging open-systems standards that fall under the umbrella of the so-called Modular Open Systems Approach (MOSA) project, including SOSA; Future Airborne Capability Environment (FACE); Vehicular Integration for C4ISR/EW Interoperability (VICTORY); and Open Mission Systems/Universal Command and Control Interface (OMS/UCI), calling these standards “vital to our success”.
5. Certify Conformance:
Openness of systems is verified, validated, and ensured through rigorous and well-established assessment mechanisms, well-defined interface control and management, and proactive conformance testing. The program manager, in coordination with the user, should prepare validation and verification mechanisms such as conformance certification and test plans to ensure that the system and its component modules conform to the external and internal open interface standards allowing plug-and-play of modules, net-centric information exchange, and re-configuration of mission capability in response to new threats and evolving technologies.
Current Open System standards
Open-systems standards like C4ISR/EW Modular Open Suite of Standards (CMOSS), Sensor Open Systems Architecture (SOSA), and Future Airborne Capability Environment (FACE) help to ensure components share a common platform and can interchange information across military branches.
Future Airborne Capability Environment (FACE) and Sensor Open Systems Architecture (SOSA) consortia are both run by the Open Group for the Air Force, Army, and Navy. Membership in each consortium consists of the services, prime contractors, and system integrators as well as embedded-system suppliers. It will revolve around computer processing and networking for command, control, communications, computers, intelligence, surveillance, and reconnaissance (C4ISR) in a technical and business collaboration that involves such systems as radar, electro-optics, infrared sensors, signals intelligence (SIGINT), electronic warfare (EW), and communications.
The FACE Consortium has most recently released the FACE Technical Standard 3.0, while the SOSA Consortium is working toward the release of its first standard. Much of the progress from both was showcased at the U.S. Air Force-hosted FACE & SOSA Expo and Technical Interchange Meeting (TIM) event, held in Dayton, Ohio.
C4ISR Modular Open Suite of Standards (CMOSS)
Current generation of C4ISR/EW systems such as communications; EW; Position, Timing, and Navigation (PNT), and mission command systems are disparate systems which result in large size, weight, and/or power requirements exceeding that is available on current and planned future platforms. “Over the past 15 or so years, the military has rushed countless systems to the field to meet immediate operational needs with little thought as how those systems worked with each other or the platforms on which they would mount.”
However the core of many of C4ISR/EW systems consist of the same building blocks, e.g., amplifiers, filters, and processors but they are not shared or distributed between systems Each additional capability or function comes as its own “system” resulting in duplicative hardware such as processors, displays, amplifiers, and antennas.
“As a result, platforms are crammed full,” Jason Dirner, head of C4ISR Modular Open Suite of Standards (CMOSS) at the Army Communication-Electronics Research, Development and Engineering Center (CERDEC) Intelligence and Information Warfare Directorate, said. “We have integrated challenges in that each system has to have a custom integration kit developed, which increases the time and cost to field the capability.” It also results in complex, costly and weighty cabling, excessive heat generation and high cost of maintaining and upgrading. This also has resulted in cognitive stress in operators due to information overload.
The US Army’s C4ISR/Electronic Warfare (EW) Modular Open Suite of Standards (CMOSS), effort is to consolidate multiple vehicle C4ISR systems onto computer cards that could be easily swapped out and tailored to meet specific mission requirements is expected to be ready for implementation in early 2018.
Transitioning to CMOSS will reduce the footprint of C4ISR systems, and will also enable the army to be able to quickly reconfigure its vehicles for specific environment, terrain, or mission requirements, instead of reintegrating components into already cluttered platforms, according to the service’s Communications-Electronics Research, Development and Engineering Center (CERDEC).
“CMOSS can radically change how EW systems are fielded,” Dirner said. “Probably most importantly, it allows flexibility that’s required in order to keep pace with emerging technology and allows us to rapidly change capabilities based on urgent needs. It also allows us to quickly field capabilities that are innovative but may not have been planned.”
CMOSS defines a converged architecture that provides open interfaces to enable rapid insertion of new capabilities, interoperability and a reduced SWaP footprint. Jason Dirner, said the Army must require open architectures that would allow system upgrades for software-defined weapon systems at most every five years.
CMOSS calls for specially designed boxes, known as common chassis, to be developed for specific platform types. This will enable the service to better synchronise vehicles within the same family during their upgrade cycles – especially between older platforms and their new-built counterparts – and maximise the potential for lifecycle cost savings.
CMOSS is a “suite” of layered standards that defined everything from the network connectivity of a specific system to the physical interface–think USB plug–through which a subsystem connects to the network.
CERDEC has defined a set of hardware and software standards to support reusable and portable software applications open up network buses on platforms, and to determine standard form factors for hardware. By requiring systems be built to those standards, the Army can integrate the best emergent technologies while ensuring they work with legacy platforms and can accept future upgrades, Dirner said.
The network layer, which is the “lowest layer,” allows services to be discovered, managed and monitored on a platform. Standards at this level dictate how a sensor lugs into the vehicle and how its software should distribute the information it gathers.
On top of that is a hardware standard that requires a card-based interface that will allow all integration to be plug-and-play. This helps to reduce the amount of cables, power supplies and processors on board an MRAP or Humvee, Dirner said.
Another aspect of the army’s transition to modular and open vehicle systems architecture is the decision to move the power amplifier from inside the vehicle and co-locate it with the antenna. Referred to as the Radiohead concept, the strategy is to design a radio-based mount with a low profile mechanical footprint that includes the electronics necessary to serve as a high-powered amplifier. The effort will free up space inside the vehicle while reducing signal loss to the antenna.
While CMOSS and Radiohead are targeted toward existing and emerging vehicles within the army’s Brigade Combat Teams (BCT), the technology can be applied to other air and ground platforms. CERDEC will demonstrate CMOSS and Radiohead to US Department of Defense and army leadership in late January, before handing it over to army acquisition officials for use in programmes of record.
“We wanted to sew all that together into a coherent suite of standards and then start developing and building prototypes that would give our partners in the acquisition community the confidence they needed to be able to procure systems this way,” Peddicord said.
The high-level goals of SOSA include openness and being platform- and vendor-agnostic while being aligned with Modular Open Systems Approach (MOSA) using standardized software and hardware. The consortium aims to leverage existing and emerging open standards and align with U.S. Department of Defense (DOD) service objectives. Finally, SOSA aims to keep technology affordable and adaptable.
The SOSA standards group involves technical experts from the U.S. military services, and has support from top leaders in the Pentagon. A memo signed earlier this year by U.S. secretaries of the Army, Navy, and Air Force, calls for military service acquisition executives and program executive officers to use open-systems standards like SOSA “to the maximum extent possible.”
The SOSA standard, supervised by the Open Group in San Francisco, aims generally at high-performance embedded computing, but is being developed specifically with signal processing in mind. The standard seeks to tame the proliferation of open-systems VPX standards and create a manageable set of interoperability guidelines for aerospace and defense systems to enable a broad variety of components from separate vendors to work together easily.
“SOSA stands for sensor [Sensor Open Systems Architecture], and they are trying to make things more interoperable with fewer different flavors of modules, interfaces, and backplanes,” explains Rodger Hosking, vice president of embedded computing and signal processing specialist Pentek Inc. in Upper Saddle River, N.J. “The SOSA effort is to reduce the degree of variability and to standardize such that multiple vendors can supply systems that are reusable and upgradable,” Hosking continues. “It’s driven by trying to save costs, and to deal with the complexity of any given system. Designers have to attack at least the part of a system at a higher, or common, level so the modules can talk to each other.”
Hosking calls this trend “an abstraction away from the very lowest level of system functions to higher-level, more consistent interfaces.” Consistency is the key, he says. “The whole mission of SOSA is to keep those interfaces as consistent as possible so you can have compatibility among different systems vendors.” Consistent interfaces, as well as higher levels of systems integration and complexity, are at the heart of SOSA — particularly for sensor and signal processing applications — says Predrag Mitrovic, senior systems architect at high-performance embedded computing expert Abaco Systems in Huntsville, Ala. “Everything is becoming more dense and integrated, which is reflected in the RF and optical backlink connectivity in the VPX ecosystem,” Mitrovic says. “In the past you have four to eight RF connects in a very dedicated space on the VPX backplane. Now this is going to 10 or 20 of those. This will allow for more connections over the backplane to ease maintenance in the future without worrying about doing the pre-wiring up-front.”
Patrick Collier, the SOSA and systems engineer for Aspen Consulting Group in Manasquan, N.J., explained that the SOSA standard applies to each module of a system rather than the entire embedded computing system itself. “The degree to which a system or element is composed of individually distinct physical and functional units that are loosely coupled with well-defined interface boundaries,” Collier says. Susan Harper, the manager of standards and certifications at The Open Group in San Francisco informed that get the “green light” as a SOSA-certified, each module will have to be verified by an accredited authority outside the company as “self-verification” is not allowed by The Open Group. In addition, certification will be done by The Open Group to “verify the verification.” The cost for certification has yet to be determined by the SOSA consortium. Verification, on the other hand, is a cost that will have to be determined by the company and the verifying authority.
Several embedded computing companies have introduced SOSA-aligned products — among them Abaco Systems in Huntsville, Ala.; Kontron; Pentek Inc. in Upper Saddle River, N.J.; Elma Electronic in Fremont, Calif.; Curtiss-Wright Defense Solutions; and Annapolis Micro Systems Inc. in Annapolis, Md.
Pentek in Upper Saddle River, N.J. announced the company’s Quartz model 5550, a SOSA-aligned eight-channel A/D and D/A converter, 3U OpenVPX board based on the Xilinx Zynq UltraScale+ RFSoC. Xilinx remarkable Zynq Ultrascale+ RFSoC [radio frequency system-on-chip] technology, integrates multi-gigasample RF data converters and soft-decision forward error correct (SD-FEC) into a MPSoC architecture. “The model 5550 is leading the industry in the rollout of products developed in alignment with the Technical Standard for the SOSA Reference Architecture,” said Bob Sgandurra, director of product management of Pentek. “Pentek continues to be very active in the development of the SOSA technical standard and we are now demonstrating our commitment with supporting products and demonstrations.”
A development decision sought to implement connector technology that enables one of the major goals of SOSA reference architecture: backplane-only I/O. The model 5550 incorporates the ANSI/VITA 67.3D VPX backplane interconnect standard for both coaxial RF and optical I/O. In addition, the model 5550 includes a 40-Gigabit-Ethernet interface and a shelf-management subsystem that also are required in the SOSA reference architecture.
The front end accepts analog RF inputs on eight coax connectors located within a VITA 67.3D backplane connector. After balun coupling to the RFSoC, the analog signals are routed to eight 4 GSPS, 12-bit A/D converters. Each converter has built-in digital downconverters with programmable 1x, 2x, 4x and 8x decimation and independent tuning. The A/D digital outputs are delivered into the RFSoC programmable logic and processor system for signal processing, data capture or for routing to other resources. A stage of IP based decimation provides another 16x stage of data reduction, ideal for applications that need to stream data from all eight A/D’s. Eight 4 GSPS, 14-bit D/A converters deliver balun-coupled analog outputs to a second VITA 67.3D coaxial backplane connector. Four additional 67.3D coaxial backplane connections are provided for clocks and timing signals.
Abaco’s SBC3511 rugged 3U VPX single-board computer was developed specifically in response to the requirement for alignment with the SOSA and CMOSS standard. The SBC3511 offers memory resources including 32 gigabytes of high speed DDR4 SDRAM and as much as 256 gigabytes NAND Flash (NVMe solid-state drive), plus a range of I/O including DisplayPort, USB, GPIO and serial comms. An on-board mezzanine expansion site is also provided for enhanced system flexibility.
The SBC3511’s Data Plane fabric connectivity is via a 40G-capable Ethernet fat pipe, with a Gen 3 capable PCI Express fat Abaco’s SBC3511 rugged 3U VPX single-board computer was developed specifically in response to the requirement for alignment with the SOSA and CMOSS standard pipe providing the Expansion Plane. Control Plane connectivity on the backplane is via two 10G capable Ethernet ultra-thin pipes with an additional 1000BASE-T thin pipe for external connection. Available in a range of air- and conduction cooled build levels with extended temperature capability, the SBC3511 is designed to meet the requirements of a wide range of applications from industrial through to fully rugged defense and aerospace programs.
“Recently, at the Georgia Tech Research Institute (GTRI) Tri-Service Open Architecture event in Atlanta, we were able to highlight our experimentation successes with the Army and the EW Planning and Management Tool,” said Peter Thompson, vice president of product management at Abaco Systems in Huntsville, Ala. “Prolonged efforts with the Army to demonstrate Abaco CMOSS alignment and SBC3511 capabilities culminated in a successful “plug and play” demonstration in a government-designed chassis.”
He continues, “What’s interesting is that demand for CMOSS- and SOSA-aligned solutions isn’t only coming from the U.S. armed forces. As the U.S. represents the majority of the market for military embedded computing, armed forces in other territories can clearly see what the future holds and are asking for similar solutions.”
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