Avionics data bus users demand more reliability and flexibility

Military Embedded Magazine

Published in Military Embedded Magazine. John McHale speaks to Mark Grovak from Curtiss-Wright Defense Solutions - excerpt below:

New and old military aircraft platforms are continuing to embrace high-speed networks in their new avionics data bus selections, choosing protocols such as high-speed Ethernet and ARINC 429. Meanwhile, MIL-STD 1553 continues to live on in new designs and sustainment contracts despite its slower speeds.

Reliability and flexibility in design are what military avionics integrators want from a data bus solution, whether it is MIL-STD 1553 or 40 GBit Ethernet. While this is a commercial off-the-shelf (COTS) market, avionics data bus users typically want the flexibility to tweak the COTS offerings for their specific needs from size, ruggedization, and cost perspectives.

“Both legacy and new-design aircraft are adding modern, high-speed networks where the requirements and the cost fit within the customers’ budgets,” says Mark Grovak of Curtiss-Wright Defense Solutions. “For new aircraft, it’s a no-brainer to go to 1 or 10 Gb Ethernet networks as they are laying out the wiring in a new aircraft. For legacy aircraft, the math is harder because of the additional cost of rewiring a legacy aircraft with the wiring that supports faster data rates.”

Ethernet, Ethernet, Ethernet

Grovak says he sees growing demand for Ethernet, as it’s the 1 Gb and 10 Gb Ethernet that are the main new data buses that Curtiss-Wright’s customers are requesting. “As the processing capability on aircraft continue to increase, the need for faster networks to move the resulting information around the aircraft will also increase. We see Ethernet as it increases from 10 GbE to 40 GbE and beyond as the main road map. Legacy applications of 2 Gb FibreChannel on F-35 and F/A-18 will be used for the foreseeable future because of the fiber-optic infrastructure in place.”

MIL-STD 1553 demand still strong

As mentioned above, reliability is the key demand from every avionics data bus customer, and what’s more reliable than 1553?

“Eventually, the transition of command/control to Ethernet data transfer buses will occur, enabled by the incorporation of enabling standards within Ethernet such as Precision Time Protocol version 2 (IEEE 1588-2008), Time Sensitive Networking, and other optimizations,” Grovak explains. “In the meantime, phased migration will occur – as the LRUs are replaced, Ethernet will be available on new hardware alongside 1553, giving platform architects options for changeover at a future point when fewer and fewer legacy LRUs are solely dependent on the existing 1553 cabling infrastructure on a platform.”

Immortalizing 1553

Some things are certain in life, such as death, taxes, and – it appears – 1553, as there are initiatives underway to give the venerable standard a touch of immortality and of course more speed.

“An important effort to extend the life of the 1553 cabling infrastructure is underway,” Grovak says. “In 2016, STANAG 7221 was released by NATO and was driven by an international effort over the last five years to standardize a high-speed data bus technology that could operate concurrently on the MIL-STD 1553B data bus without impacting the MIL-STD 1553B signaling and without modification to the existing data bus infrastructure. STANAG 7221 has been successfully validated in both fixed- and rotary-wing platforms.”

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