Military Embedded Systems

SAVE this space: Defining the C5ISR space for Army vehicles


February 04, 2022

Jason DeChiaro


[Figure 1 | The eight-slot CMOSS/SOSA enclosure is a powered enclosure aligned to CMOSS/SOSA Technical Standard 1.0.]

To lower the cost and help speed the pace of technology upgrades for C5ISR [command, control, computers, communications, cyber, intelligence, surveillance, and reconnaissance] systems on Army vehicles – while supporting the U.S. Department of Defense (DoD) mandate for modular open system architecture (MOSA) solutions – the U.S. Army’s Program Executive Officer (PEO) for Ground Combat Systems (GCS) has issued an Interface Description Document (IDD) that describes the Standardized A-Kit/Vehicle Envelope (SAVE), a new physical SWAP and connector standard for fielding new C5ISR capabilities.

The Standardized A-Kit/Vehicle Envel­ope (SAVE), which stipulates the internal mounting and physical interfaces for connecting CMOSS [C5ISR Modular Open Suite of Standards] solutions such as radios, to platforms, is primarily intended for new integrations and systems. SAVE is only intended for modular systems that electrically or digitally integrate into Army platforms, and isn’t relevant to stowed equipment, vehicle elements such as engines or weapons, or external components such as antennas or armor.

Intended to speed and simplify the installation of C5ISR [command, control, computers, communications, cyber, intelligence, surveillance, and reconnaissance] systems in Army vehicles, SAVE regularizes the size, shape, and physical interfaces (RF, data, power, etc.) for mounting those systems. SAVE joins the CMOSS standards – such as VICTORY, MORA, and OpenVPX – already called out by the GCS Common Infrastructure (GCIA) framework, but SAVE covers only the purely physical elements instead of how data flows between the systems integrated on a vehicle.

One of the key goals of SAVE is to lower the cost of deploying new C5ISR capabilities on combat vehicles. It accomplishes this by minimizing the time and effort of integrating SAVE-compliant systems into SAVE-compliant vehicles by ensuring that systems fit into the same size envelope, use the same mounting holes, and have the same connector types. The standard provides extra cable loops to support adaptation between systems without requiring new wiring.

The SAVE IDD [Interface Description Document] recognizes the need for flexibility, so instead of taking the approach of a rigid military specification, it understands that vehicle and system PMs will sometimes only call out a subset of the SAVE IDD language in formal proposals and contracts as appropriate. The IDD states that “perfect compliance across all vehicles and PMs is not expected” and provides direction for handling those cases where variations are needed.

Because the SAVE IDD defines only the outer envelope (maximum dimensions), a wide variety of possible configurations are permitted within the envelope. The idea is to provide flexibility within the standard to encourage innovation and competitive acquisition. The standard physical volume defined by SAVE is based on the standard existing radio shelves envelope, measuring 15.9 inches wide by 16.1 inches deep and 9.3 inches tall, about the size of a dorm room microwave. Within those maximum rectangular dimensions any size and shape of subsystem is allowed, and adaptor plates can be used to mount smaller devices as long as they fit within the set dimensions. Connectors defined within SAVE include RF cables at radio, RF cables at antennas, RF-GPS, power input, power output, plus audio and data cable types.

SAVE specifies ATPD 2407A 2404A Interface Standard Environmental Conditions for Ground Combat Systems and ATPD Electromagnetic Environmental Effects (E3) for U.S. Army Tank and Automotive Vehicle Systems tailored From MIL-STD-464C for vibration, operating temperature, and RF tolerances.

Examples of C5ISR solutions addressed by the SAVE standard include handheld, manpack and small form fit – manpack (HMS-MP) data radio; legacy SINCGARS radios; future CMOSS systems; capability set (CS, ITN) systems; IVAS Mounted Soldier and Nett-Warrior support kits; and robotic systems with manned ground vehicles. SAVE will facilitate the integration of new radios, waveforms, Assured Position Navigation Timing (A-PNT) systems, electronic warfare (EW) systems, and vehicle protective systems (VPS) components and subsystems.

Examples of CMOSS chassis designed to meet SAVE requirements are the Curtiss-Wright CMOSS/SOSA Starter Kit (CSSK), which carries a preintegrated four-slot SWaP-optimized SOSA aligned 3U VPX system combining a VICTORY network module, A-PNT module, single-board computer, and 3U VPX power supply unit; another is the eight-slot CMOSS/SOSA enclosure (Figure 1), a powered enclosure aligned to CMOSS/SOSA Technical Standard 1.0.

[Figure 1 | The eight-slot CMOSS/SOSA enclosure is a powered enclosure aligned to CMOSS/SOSA Technical Standard 1.0.]

Jason DeChiaro is a system architect at Curtiss-Wright.

Curtiss-Wright Defense Solutions •

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