Prepare for Network-Centric Military Systems

Can modularity and fabric throughput hold together the next generation?

Today, military-force transformation is guided by a vision of network-centric operations. The goal of this effort is to accelerate the use of technology to provide seamless communications, collaboration, and situational awareness across all branches of service—securely and reliably. This movement requires VMEbus technology to evolve and offer greater performance, higher I/O bandwidth, and backward compatibility with the VME64 protocol.

“VME was all about I/O and the applications they directly supported. As a result, communications were more localized and information sharing was limited—and as such, tanks didn’t send data back to the command center. Now, there’s a network that connects the command center, troops in the battlefield, unmanned vehicles, and other military assets, providing more information from the theatre of operations. It boils down to having actionable information at the tip of the spear,” says Clayton Tucker, senior marketing manager for the Embedded Computing business of Emerson Network Power.

VPX, one of the successors to VME, delivers the requisite performance and bandwidth for most next-generation military systems. But other factors, including modularity and fabric throughput, are also crucial. The following expresses the views of several industry participants.

Modularity Is Key

The network-centric warfare vision imposes significant system- level requirements, including the need for complex systems to interoperate and provide backward compatibility with current force systems. “Modularity will enable the network-centric vision put together by the DoD. Modularity is the only way that the DoD will be able to achieve network-centric systems,” asserts Joe Jensen, general manager of the Intel® Embedded Computing Division.

The root of modularity is interoperability. VPX is experiencing some growing pains in this area that are partly due to an early proliferation of board-level architecture options. Recognizing the VPX interoperability and system-management challenges, Mercury Computer Systems initiated the OpenVPX™ Industry Working Group. Its charter is to publish a comprehensive system design guide addressing interoperability for VPX boards, 3U and 6U. “The OpenVPX systemlevel approach will enable prime contractors to greatly reduce the time required to create integrated COTS solutions in 3U and 6U form factors,” says Didier Thibaud, senior vice president and general manager of Advanced Computing Solutions at Mercury. “It will also lower the risk of adoption and expand the addressable market for VPX solutions while accelerating deployment into real-world applications.”

Fabric Is 10 Gigabit Ready

Network-centric military systems, which access data from anywhere, must guarantee fast, secure, and reliable information sharing. Therefore, it’s essential that the switch fabric can withstand the test of time in terms of throughput and longevity.

“VPX is the future of rugged COTS computing, already mandated by the larger defense programs and the high-frequency processing required by many of the modernized battlefield applications. With connectors designed to support high-frequency signals—unlike VME—military designers now have a reliable fabric solution with checking and retransmission that will be easy to work with and offered on board. For example, 10 Gigabit Ethernet can take in a fast data rate and dispatch it to several processors that manage the workload in parallel. The ability to design in this kind of functionality makes VPX an ideal platform for network-centric military systems, leveraging more I/O per slot and the highest computing density of today’s silicon,” says Joe Eicher, director of sales for military, aerospace, and government for the eastern North America region at Kontron.

VITA 46.20 defines a central switch slot with x1 and x2 channels that will enable an Ethernet control plane for out-of-band communication. The Figure shows an implementation in which the primary fabric is implemented in a twisted ring that makes use of only two fat pipes on each of the five node cards. The implementation also supports two x2 thin pipes utilizing a VITA 46.20 Ethernet switch card in slot 6.

Figure: 3U VPX Port Configuration implementation where the primary fabric is implemented in a twisted ring that makes use of only two fat pipes on each of the five node cards.

Justin Moll, director of marketing at Elma Bustronic, explains, “The VITA 46.20 configuration shown in the Figure supports:

  • Two x4 primary fabric channels (A-D) in each slot, which support two bi-directional 10G Ethernet or bi-directional 10G Serial RapidIO channels in a twisted ring
  • Two x4 10 Gigabit channels (G-H) that could be dual 1GBASE-KX Ethernet or 1GBASE-T Ethernet plus all J2 channels (A-H), which allow up to 24 bi-directional ports that can be utilized entirely for rear-panel I/O.”

“VPX provides equipment manufacturers the opportunity to leverage industry-standard fabric interconnects (e.g., VITA 46.3 VPX Serial RapidIO or VITA 46.4 VPX PCI Express) to ensure successful interoperability between COTS solutions. A single VPX system design is often very complex and will support multiple interconnects, such as VME64, PCI Express, and Serial RapidIO. Support for these protocols enables a powerful and flexible design by providing backward compatibility with legacy systems (VME64 protocol), processor- to-I/O connectivity (PCI Express protocol), and peer-to-peer multiprocessing (Serial RapidIO protocol) within a single system,” says Tracy Richardson, vice president of marketing at Tundra.

Network-centric systems will push the limits on performance and I/O bandwidth. To succeed, they will use modularity and fabric throughput as the glue that enables seamless communications.

Craig Szydlowski is a contributing editor to Embedded Intel® Solutions. His has over twenty years of semiconductor and embedded market experience. He holds a BSEE from Yale University and an MBA from the Wharton School.