Ruggedized network components keep critical data flowing

Networks are pushing ever closer to the edge to give commanders and troops immediate and enhanced situational awareness. Yet long before critical data begins flowing, components and systems such as switches, routers, access points, base stations and mobile devices must be ruggedized to cope with any environment they may eventually be deployed into.

Getting network components and systems to work reliably in tactical settings requires a constant struggle against the forces of man and nature, said Maj. Nathan Cahoon, C4 branch head at the Marine Corps Warfighting Laboratory’s technology division in Quantico, Va, "We take into account cold, heat, water, shock and vibration," he said. "We try to take a look at all these things, because as the Marine Corps and an expeditionary force we could end up anywhere."

Harden and Test

Building ruggedized switches, routers, network access points and other types of network hardware requires a level of physical hardening that goes well beyond the requirements and needs of virtually any civilian customer. "There will always be minimum goals for ruggedness—from altitude to shock and vibration to thermal conditions," said Wayne Eagleson, general manager at Herndon, Va.-based LGS Innovations, which supplies network technologies to the federal government.

Most ruggedized network components and systems are based on MIL-STD-810, which includes some two dozen defined areas covering both testing and environmental evaluation, Eagleson said, adding that “specific benchmarks depend upon the unique procurement document.”

Chris Boutilier, president of SIE Computing Solutions, a Brockton, Mass.-based company that specialized in ruggedized systems for use in mission critical environment, noted that Defense Department typically supplies the benchmark as a flow-down document to all of the parties involved ruggedized equipment production and procurement. "These benchmarks are tried and proven testing requirements that serve as guidelines within the military industry," he said.

Ruggedization begins during the product’s initial design phase, including the placement of wires, the type of solder used and even circuit device attachment methods. The product’s final form factor also plays a major role in ensuring durability and reliability. “The physical design, aerodynamics and heat resistance all have to be accounted for and built in to meet specifications," Eagleson said. "Ruggedization is planned from inception, it can’t be an afterthought."

Manufacturers must also ensure that ruggedization doesn't interfere with the attachment of external accessories or blocks future internal upgrades. "From a design perspective, leaving a bit of headroom is important to provide a margin for system enhancements that are typical as equipment evolves," Boutilier said.

Koroush Saraf, senior director of product management for network security appliance vendor Fortinet, headquartered in Sunnyvale, Calif., noted that his firm's FortiAP-222B outdoor access point is built to withstand rain, humidity, salt fog, sand/dust, vibration, shock and extreme temperature ranges. "The main goal is to provide customers with equipment that meets or exceeds their [desired] MTBF when subjected to these extreme conditions," he said. Saraf added that tests on the Forti AP-22B include a water depth test that's designed to ensure full operation at a depth of 1 meter, as well as drop, temperature and corrosion tests.

For its base station products, Eagleson says that LGS runs localized tests that include placing the product inside a heat chamber, RF interference testing and testing for environmental factors such as humidity, shock and vibration.

Parts and Boards

When it comes to network deployment on the tactical edge, even something as basic and simple as an RJ-45 network connector may require ruggedization. Mike Southworth, marketing director for Parvus, a Salt Lake City-based company that ruggedizes network hardware for military applications, noted that the widely used connectors are "notoriously prone to failure under extreme vibration and do not provide ingress protection against dust and water." To address these issues, Parvus engineers remove and replace commercial-grade RJ-45 connectors with locking headers that terminate into circular MIL-DTL-38999-type connectors designed for resistance against dust, water, vibration and shock.

Tactical edge deployments can literally stress systems down to their very core, subjecting circuit boards and electronic components to extreme levels of shock, vibration, heat and moisture. To achieve ruggedization on its products, LGS hardens systems all the way down to discreet board-level components. "LGS selects capacitors, resistors and other components rated to specific, stringent environmental conditions," Eagleson said.

Chips and other circuit board components need to remain firmly in place as they're subjected to extreme levels of vibration and shock, often requiring vendors to resort to exotic adhesive approaches. One such technique is underfilling—injecting a specialized glue that's designed to keep the chips in place as they're buffeted about. "Its application provides a strong mechanical bond between the ... component and the corresponding connection to the circuit board, protecting the solder joints from mechanical stress," Southworth said.

User Devices

Beyond the network itself user access devices such as fixed, portable and mobile computers, as well as radios, smart phones and tablets, all require at least some ruggedization to be able to function dependably within extreme environments. Austin, Texas-based Xplore Technologies, which sells a ruggedized tablet designed for tactical military use, addresses the challenge by adding extra protection both inside and outside the system. Mark Holleran, Xplore's president, notes that the firm protects tablets by installing "a flexible but stabilizing inner frame, combined with a mag alloy housing and a bumper system [that's] optimized to protect the operating components, display and user data." According to Holleran, the added protection is sufficient to allow the system to operate under a variety of hostile conditions. "Hot and cold, dry talcum—like dust—and driving rain, salt water and salt fog, even operating 1 meter under water for 30 minutes," he said.

With smaller, lighter mobile devices such as smart phones, which are inherently more shock resistant, it's often possible to create an acceptable amount of ruggedization simply by inserting the unit into a consumer-grade hard case. "There are multiple levels of commercial, off the shelf solutions available to protect devices," Cahoon said. He observed that OtterBox, a mobile device case manufacturer located in Fort Collins, Colo., provides products that are designed to absorb a great deal of shock and vibration. "You have a hard case with rubber that goes over the case, so you not only have the rubber for [shock] absorption, but you have the hard shell for even more absorption," he said.

Cahoon observed that he also evaluated consumer off-the-shelf cases that are designed to protect systems against water intrusion as well as shock. "OtterBox has a case with sealed input/output ports so it could be submerged in water," he said. "If you had to ford across a canal or something like that ... it could be under water and you could still be plugged into it."

Most vendors ultimately view ruggedization not only as a process that helps them win contracts, but as a duty to troops whose lives depend on access to highly functional and dependable networks. "Ruggedization is like a badge of honor," Eagleson said.