Due to harsher working environments, soft errors or erroneous bit-flips occur more frequently in microcontrollers during execution. Without mitigation, such errors result in data corruption and control flow errors. Multiple software-implemented mitigation techniques have already been proposed. In this paper, we evaluate seven signature monitoring techniques in seven different test cases. We measure and compare their detection ratios, execution time overhead, and code size overhead. From the gathered results, we derive five requirements to develop an optimal signature monitoring technique. Based on these requirements, we propose a new signature monitoring technique called random additive signature monitoring (RASM). RASM uses signature updates with random values and optimally placed validity checks to detect interblock control flow errors. RASM has a higher detection ratio, lower execution time overhead, and lower code size overhead than the studied techniques.

In this paper, different techniques and measures are described and discussed that are effective to reduce risks related to electromagnetic disturbances in mission- or safety-critical systems. The aim of these techniques and measures is to make a system EMI-resilient or fault-tolerant with respect to EMI. Whenever a fault occurs within the system, the techniques and measures should either allow that the system continues to work in a safe manner (possibly with reduced performance) or trigger that the system is switched to a safe-state. The techniques and measures align with the well-proven techniques and measures described in IEC 61508, the main standard in the field of Functional Safety. It is described how they have to be modified or optimized to be effective for EMI. At the end of the paper, the use of inversion and spatial diversity is studied in more detail, thereby giving guidance on possible pitfalls.

Bluetooth Low Energy (BLE) is a popular wireless communication protocol heavily used in Internet of Things applications. Nowadays, robustness is considered a key requirement in wireless communication. However, radio interference from various sources may affect the performance of BLE devices, leading to channel congestion. Therefore, there is a broadly recognized need of methodologies capable of sensing and avoiding interference. In this paper, two improvements at the data link layer for interference detection and channel selection are proposed to enhance the BLE connection robustness. This paper also presents a wide range of experimental evaluations aiming at validating the improvements and providing insights on both these improvements. Particularly, the communication performance of the BLE link layer is assessed in terms of channel usage distribution, supervision timeout ratio (STR) and packet loss rate (PLR) under different interference environments. Results from these experiments (reliability over 97% and 99% under two different harsh environments) highlight the effects of both improvements on the BLE robustness. Meanwhile, the authority of scheduling the whole mechanism is given to the link layer and even the higher application layer. This paper provides a set of solutions for BLE confronting interference in link layer.

In this paper, the effectiveness of applying an extra time delay to the data transmitted over redundant channels to cope with harsh electromagnetic interference is studied. The redundant system is compared with and without extra time delay and compared with a non-redundant system, which is the reference situation. The geometries under study are disturbed by strong incident fields, which represent reverberation room conditions. These conditions refer to the planewave integral representation, where multiple planewaves with random angles, polarisations and phases are combined and normalised, to create a reverberation room like environment. A reciprocity based technique is used to efficiently calculate the induced voltages and the resulting bit error rate for the different situations. Because of the properties of the geometries that are under test and the introduction of a time-delay in the transmitted datastream, the moment the induced voltage due to EMI is sampled is different, which causes an EMI-diverse system. The results show that using time-diverse signals optimized for the main disturbance frequency to be expected, is a very effective way of creating EMI-diverse behaviour. In a majority voting (2oo3) system it is possible to eliminate all triple occuring faults. Even for higher field strengths and different EMI frequencies, the time diversity method performs well (better than other EMI-diverse techniques).

Modern hi-tech systems rely heavily on communication networks while operating in increasingly harsher electromagnetic conditions. To protect transmitted data from corruption, Error Correcting Codes are widely used. In this paper, the effectiveness of the Hamming code is evaluated under harsh electromagnetic disturbances. Our simulations show that, under certain conditions, the impact of the introduced overhead cannot be compensated by the single error correcting capabilities of the Hamming codes. Moreover, for specific bit and disturbance frequencies and for larger data sets, the use of a Hamming code provides limited to no advantage.