Dedicated bus architectures have been traditionally used in military applications, including UAVs, but resulted in heavier, proprietary and more inflexible systems. Ethernet has been shown as a viable alternative for military UAV applications for a number of reasons:
Robustness: Previous generations of connectivity were vulnerable to the elements that a UAV faced in normal conditions — dirt, moisture, temperature deviations and vibration can all reduce standard bus architecture connectivity efficacy and efficiency. Ethernet is a more solid and dependable connectivity platform; and interconnectivity between switches can make the connections even more reliable. For example, multiple switches can be used in UAVs to provide redundancy and to eliminate the possibility of a single point of network failure: switches are interconnected so that the failure of a switch or link between switches can be avoided by routing around the failure.
Diagnostics: Managed Ethernet switches can increase the resiliancy of the internal communication of the UAV. The system can be set to self-detect and self-manage modules, and add to the UAV’s uptime.
Failure Isolation: In some bus architectures, modules that communicate with each other via direct electrical connections can crash the entire system if one module fails. Modules are electrically isolated in Ethernet architecture, so if one module fails, the loss is limited to the loss of that module.
Flexibility: The modularity of Ethernet components allows for UAVs to have design and implementation flexibility. UAVs can be built for more than one function because of the flexibility of Ethernet components, and UAVs in the field can be modified and outfitted to fit specific needs.
Size/Weight/Power: Every ounce of decreased weight means more flight time for UAVs, so every ounce of component weight must provide and maintain optimal system performance. Each square inch must carry as much functionality as possible. Power management is also a challenge. Finding a balance is critical. Lightweight, rugged Ethernet switches are an excellent combination to make the most of SWaP-C (size, weight, power and cost) pressures and constraints, as they save real estate room on a UAV for other devices.
As the desired functions for UAVs grow, UAV technology constantly faces new requirements and tasks, which necessitates changing approaches to design and systems. On-board Ethernet connectivity facilitates much of the design flexibility to meet the ever-changing demands for UAVs. For this reason, Ethernet has become the connectivity platform of choice for military UAV system designers.
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