SWaP gains enlist MicroTCA in the military

SWaP gains enlist MicroTCA in the military

As the trend continues towards low Size, Weight, and Power (SWaP) Unmanned Systems (USs), MicroTCA's small footprint, rugged characteristics, and robust bandwidth are catching the eyes of military leaders.

4Network-centric architectures are now a prevalent requirement in today’s military systems, such as those that manage communications across multiple security enclaves. Even applications that aren’t seemingly network centric, such as radar beamforming and processing, often are implemented using network-centric COTS architectures with multiple compute nodes networked together to essentially implement a mini-supercomputer. At the same time, SWaP reduction is always desired, if not required, especially for aerial and unmanned platforms.

MicroTCA’s switched serial network architecture and small form factor make it a logical option for these types of applications. Growth of MicroTCA in military deployments has been fueled by additional MicroTCA specifications that add the ruggedness required for harsh deployments. Conduction-cooled and rugged air-cooled specifications have been ratified by PICMG, and these types of MicroTCA systems are being deployed in military environments worldwide. Looking forward, another rugged MicroTCA specification will be available later this year that allows higher power modules to be used in these rugged environments.

’s switched serial network architecture and small form factor make it a logical option for these types of applications. Growth of MicroTCA in military deployments has been fueled by additional MicroTCA specifications that add the ruggedness required for harsh deployments. Conduction-cooled and rugged air-cooled specifications have been ratified by , and these types of MicroTCA systems are being deployed in military environments worldwide. Looking forward, another rugged MicroTCA specification will be available later this year that allows higher power modules to be used in these rugged environments.

Meeting the need for high bandwidth and high-end processing in a standards-based small form factor is attractive to military designers seeking advantages in size, scalability, and communications bandwidth. These same demands are typical for telecommunications designers. In fact, many of the demands typical of a deployed telecommunications system are similar to the network-centric systems being used in military settings, making MicroTCA (“TCA” stands for “Telecommunications Computing Architecture”) an effective mission-critical platform that offers high communications bandwidth, high processing capacity, and high reliability.

Making MicroTCA tick

The heart of MicroTCA is the Advanced Mezzanine Card (AMC) payload board, a 2U circuit card Assembly with 21 high-speed serial connections to the backplane, each capable of delivering bandwidth of at least 2.5 Gbps. A single system can include up to 12 AMCs communicating with each other via the high-speed serial links, typically implementing a combination of Gigabit Ethernet (GbE), 10 GbE, PCI Express, Serial , SATA and/or SAS connections. MicroTCA also defines a standard profile for how each of the 21 serial connections (ports) should be used if implemented. For example, ports 0 and 1 are typically GbE for the control plane, while ports 4-11 can be used as x1, x2, x4, or x8 fat pipes for data plane communications. Figure 1 shows the port mapping for a typical processor AMC SBC.

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Figure 1: MicroTCA defines the port mapping of typical AMC SBCs.

Communications topologies can be a combination of star, dual star, or point-to-point. The star or dual star topology is typical for the control plane. A system’s communications bandwidth capacity can range from 40 Gbps to greater than 1 TBps, depending on how the system is implemented. An example topology including both star and point-to-point topologies is shown in Figure 2.

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Figure 2: An example of the star and point-to-point topologies found in communications systems.
(Click graphic to zoom by 1.4x)

Making MicroTCA rugged

Even the telecom-focused version of MicroTCA has some rugged underpinnings. MicroTCA boards and systems by specification must allow compliance to Network Equipment Building Systems (NEBS) Level 3 requirements, which validates thermal margins, fire suppression, emissions, and the ability to remain operational during a severe earthquake. NEBS-certified MicroTCA boards and systems are validated to withstand extreme heat, humidity, altitude, and up to Zone 4 earthquake shock (7.0 Richter scale and higher), as well as an extensive range of other extreme environmental conditions. Being smaller than a 3U or board, an AMC’s small size helps in rugged environments. Smaller size means less bending and flexing under shock and vibration loads.

Further growth of MicroTCA in military deployments is fueled by add-on specifications that make the most of its rugged family tree. Certified by PICMG, these new specifications for rugged air-cooled and conduction-cooled derivatives leverage the ANSI/VITA 47 specification and define the environments in which these certified boards will perform.

For example, in 2011 PICMG announced the adoption of the (.3) specification. This specification defines the requirements for systems needing to meet more stringent levels of temperature, shock, vibration, and other environmental conditions, addressing military and some commercial systems in sealed environments with no airflow at all. MTCA.3 does this by placing the AMCs inside of a metal clamshell, with wedge locks to stiffen the board and also provide a conductive path for thermal dissipation through the chassis. Typical applications include military systems hard mounted to a mobile platform (an ATR is one example), or military communications systems deployed outdoors.

Similarly, MTCA.1 specifies a rugged air-cooled flavor of MicroTCA. Currently underway is MTCA.2, which employs a novel hybrid air- and conduction-cooling approach to maximize the amount of heat that can be effectively dissipated. The result will mean that systems in higher temperature environments will be able to more effectively use higher power modules.

There may be multiple MTCA derivatives that answer a system architect’s long list of design issues. With each of these related specifications, the goal is to reuse the exact same AMC printed circuit board and as much of the MTCA base specification infrastructure as possible. Figure 3 shows an overview of the PICMG MicroTCA specifications.

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Figure 3: An overview of the PICMG MicroTCA specifications.

MicroTCA for net-centric applications

When it comes to network-centric applications, MicroTCA’s telecom heritage makes it a logical COTS architecture choice. For example, when considering a secure network application, system designers must first determine the level of inbound and outbound data, as well as what tasks must be performed while the data is moving through the network. Once the performance environment indicates that data processing is approaching the demands of 10 GbE, MicroTCA becomes an ideal option. An example of one such system is the Space Network Ground Segment Sustainment (SGSS) project, an effort to modernize the ground segment of the satellite communications network used by the National Aeronautics and Space Administration (NASA).

SGSS relies on satellites and spacecraft in low-Earth orbit to continuously relay data to ground stations in White Sands, New Mexico and in Guam. Data is relayed through the Tracking and Data Relay Satellite System (TDRSS) network, the central focus of the SGSS initiative. Modernization will improve situational awareness for TDRSS network operators by upgrading computing and equipment, as well as enhancing reliability and maintainability, improving efficiency, and reducing operations and sustainment costs.

MicroTCA in applications

While systems deployed on most military platforms struggle with SWaP (Size, Weight, and Power) requirements, SWaP comes to the forefront most when designing systems for unmanned applications.

For example, consider an unmanned platform for ISR (Intelligence, Surveillance, and Reconnaissance). These platforms are typically performing computationally intensive tasks onboard such as beamforming and filtering to sift through multiple streams, which are typically coming in at less than 1 Gbps. Although the network bandwidth alone would not necessitate the use of MicroTCA, the compute payload can be significantly smaller and lighter when using MicroTCA as compared to a 6U or even 3U COTS architecture. This has led to the adoption of rugged MicroTCA in unmanned platforms.

The future of MicroTCA

MicroTCA has proven itself as a military computing architecture, and will only become more relevant as the move toward secure network communications and higher bandwidth data grows steadily throughout military operations. Military leaders are under constant pressure to choose the right technology path – investing in the future versus maintaining and expanding current systems. MicroTCA’s high connectivity in a small footprint ensures that its adoption will continue to grow in this space, as do its newer rugged variants.

David Pursley is an Applications Engineer with Kontron, responsible for business development of the MicroTCA, , CompactPCI, and ThinkIO product lines in North America.

Kontron

david.pursley@us.kontron.com

www.kontron.com