Browse Topic: Communication systems
ABSTRACT The authors studied the effects of different types of armor on the performance of spin-torque microwave detectors (STMD). Working prototypes of novel nano-sized spintronic sensors of microwave radiation for battlefield anti-radar and wireless communications applications are being integrated into Sensor Enhanced Armor (SEA) and Multifunctional Armor (MFA) and tested in SEA-NDE Lab at TARDEC. The preliminary theoretical estimations have shown that STMD based on the spin-torque effect in magnetic tunnel junctions (MTJ), when placed in the external electromagnetic field of a microwave frequency, can work as diode detectors with the maximum theoretical sensitivity of 1000 V/W. These STNO detectors could be scaled to sub-micron size, are frequency-selective and tunable, and are tolerant to ionizing radiation. We studied the performance of a STMD in two different dynamical regimes of detector operation: in well-known traditional in-plane regime of STMD operation and in recently discovered novel out-of-plane regime.
To this point in aviation history, a typical aircraft type certification program has focused on the constituent systems that make up the aircraft, decomposing them further and further down until reaching their elemental parts and how they interact. This approach has traditionally treated the actual communication technology as only an interface, with technology and implementation based on a decision between multiple stakeholders via an ICD and high-level requirements. This has been necessary to ensure the accurate and on-time delivery of safety-critical data between nodes. When using legacy point-to-point or bus-based data communication technologies like ARINC 429 or MIL-STD-1553, this approach has worked well enough as these technologies are relatively straightforward and proven technologies. However, as onboard bandwidth needs for safety-critical data increase, these legacy technologies are increasingly no longer capable of meeting the needs of system integrators. Ubiquitous, high-bandwidth Ethernet is the obvious solution to these needs and, indeed, it has been used for quite some time in onboard networking applications for low Development Assurance Level (DAL)/non-safety critical data. However, as Ethernet moves into high-DAL applications, the certification of the Ethernet network itself becomes a major complexity that must be addressed directly.
There is a shift in the industry driving avionics manufactures to provide more interactive connectivity than they have had to in the past. The increasing threat of cyber security attacks in our communication systems is an increasing problem in our society and the avionics industry cannot ignore the fact that the threats are real and they must protect the systems from these attacks. Another element driving these concerns is the implementation of the FAA's NextGen or EASA's SESAR technologies which will require avionics vendors to replace their proprietary, relatively isolated embedded computer systems with information systems that interoperate and share data throughout FAA's/EASA's operations. In order to make the National Airspace (NAS) operate in the most efficient way all aircraft and ground systems will need to share information. The FAA and EASA have released standards to address these systems. This paper is only going to address aspects of security from a software perspective; more specifically, what an operating system and its environment should provide as a foundation for the security requirements. It is important to note that a generic solution to any security problem does not exist. Providing a complete security solution is the result of going through and addressing the airworthiness security process (AWSP).
ABSTRACT
The security of connected health technology is often assumed to exist when it does not, or considered to be prohibitively expensive or complex, or, worst of all, relegated to an afterthought. This is dangerous thinking, especially as the industry increasingly moves to a smartphone-based command-and-control model for these safety-critical applications.
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