Biblio

Global Navigation Satellite System (GNSS) jamming is an evolving technology where new modulations are progressively introduced in order to reduce the impact of interference mitigation techniques such as Adaptive Notch Filters (ANFs). The Standardisation of GNSS Threat reporting and Receiver testing through International Knowledge Exchange, Experimentation and Exploitation (STRIKE3) project recently described a new class of jamming signals, called tick signals, where a basic frequency tick is hopped over a large frequency range. In this way, discontinuities are introduced in the instantaneous frequency of the jamming signals. These discontinuities reduce the effectiveness of ANFs, which unable to track the jamming signal. This paper analyses the effectiveness of interference mitigation techniques with respect to frequency-hopped tick jamming signals. ANFs and Robust Interference Mitigation (RIM) techniques are analysed. From the analysis, it emerges that, despite the presence of frequency discontinuities, ANFs provide some margin against tick signals. However, frequency discontinuities prevent ANFs to remove all the jamming components and receiver operations are denied for moderate Jamming to Noise power ratio (J/N) values, RIM techniques are not affected by the presence of frequency discontinuities and significantly higher jamming power are sustained by the receiver when this type of techniques is adopted.

Aiming at the problems of poor stability and low accuracy of current communication data informatization processing methods, this paper proposes a research on nonlinear frequency hopping communication data informatization under the framework of big data security evaluation. By adding a frequency hopping mediation module to the frequency hopping communication safety evaluation framework, the communication interference information is discretely processed, and the data parameters of the nonlinear frequency hopping communication data are corrected and converted by combining a fast clustering analysis algorithm, so that the informatization processing of the nonlinear frequency hopping communication data under the big data safety evaluation framework is completed. Finally, experiments prove that the research on data informatization of nonlinear frequency hopping communication under the framework of big data security evaluation could effectively improve the accuracy and stability.

In cognitive radio networks (CRNs), secondary users (SUs) are vulnerable to malicious attacks because an SU node's opportunistic access cannot be protected from adversaries. How to design a channel hopping scheme to protect SU nodes from jamming attacks is thus an important issue in CRNs. Existing anti-jamming channel hopping schemes have some limitations: Some require SU nodes to exchange secrets in advance; some require an SU node to be either a receiver or a sender, and some are not flexible enough. Another issue for existing anti-jamming channel hopping schemes is that they do not consider different nodes may have different traffic loads. In this paper, we propose an anti-jamming channel hopping protocol, Load Awareness Anti-jamming channel hopping (LAA) scheme. Nodes running LAA are able to change their channel hopping sequences based on their sending and receiving traffic. Simulation results verify that LAA outperforms existing anti-jamming schemes.

Current BLE transmitters are susceptible to selective jamming due to long dwell times in a channel. To mitigate these attacks, we propose physical-layer security through an ultra-fast bit-level frequency-hopping (FH) scheme by exploiting the frequency agility of bulk acoustic wave resonators (BAW). Here we demonstrate the first integrated bit-level FH transmitter (TX) that hops at 1$μ$s period and uses data-driven random dynamic channel selection to enable secure wireless communications with additional data encryption. This system consists of a time-interleaved BAW-based TX implemented in 65nm CMOS technology with 80MHz coverage in the 2.4GHz ISM band and a measured power consumption of 10.9mW from 1.1V supply.

Practical intrusion detection in Wireless Multihop Networks (WMNs) is a hard challenge. It has been shown that an active-probing-based network intrusion detection system (AP-NIDS) is practical for WMNs. However, understanding its interworking with real networks is still an unexplored challenge. In this paper, we investigate this in practice. We identify the general functional parameters that can be controlled, and by means of extensive experimentation, we tune these parameters and analyze the trade-offs between them, aiming at reducing false positives, overhead, and detection time. The traces we collected help us to understand when and why the active probing fails, and let us present countermeasures to prevent it.