Equalization in redundant channels

A miscomparison between a channel's configuration data base and a voted system configuration data base in a redundant channel system having identically operating, frame synchronous channels triggers autoequalization of the channel's historical signal data bases in a hierarchical, chronological manner with that of a correctly operating channel. After equalization, symmetrization of the channel's configuration data base with that of the system permits upgrading of the previously degraded channel to full redundancy. An externally provided equalization command, e.g., manually actuated, can also trigger equalization

On the properties of device-free multi-point CSI localization and its obfuscation

The use of Channel State Information (CSI) as a means of sensing the environment through Wi-Fi communications, and in particular to locate the position of unaware people, was proven feasible several years ago and now it is moving from feasibility studies to high precision applications, thus posing a serious threat to people's privacy in workplaces, at home, and maybe even outdoors. The work we present in this paper explores how the use of multiple localization receivers can enhance the precision and robustness of device-free CSI-based localization with a method based on a state-of-the-art Convolutional Neural Network. Furthermore, we explore the effect of the inter-antenna distance on localization, both with multiple receivers and with a single MIMO receiver. Next we discuss how a randomized pre-filtering at the transmitter can hide the information that the CSI carries on the location of one person indoor. We formalize the pre-filtering as a per-frame, per-subcarrier amplitude multiplication based on a Markovian stochastic process, and we discuss different signal clipping and smoothing methods highlighting the existence of a trade-off between communication performance and obfuscation efficiency. The methodology can in any case guarantee almost unhampered communications with very good localization obfuscation. Results are presented discussing two different ways of exploiting the multi-receiver or multi-antenna redundancy and how, in any case, properly randomized pre-distortion at the transmitter can prevent localization even if the attack is carried out with multiple localization devices (receivers controlled by the attacker) and not only with a multi-antenna (MIMO) receiver

AntiSense: Standard-compliant CSI obfuscation against unauthorized Wi-Fi sensing

Channel State Information (CSI)-based localization with 802.11 has been proven feasible in multiple scenarios and is becoming a serious threat to people's privacy in workplaces, at home, and maybe even outdoors. Countering unauthorized localization without hampering communications is a non-trivial task, although some very recent works suggest that it is feasible with marginal modification of the 802.11 transmission chain, but this requires modifying 802.11 devices. Furthermore, if the attacker controls two devices and not just a receiver, transmission side signal manipulation cannot help. This work explores the possibility of countering CSI based localization with an active device that, instead of jamming signals to avoid that a malicious receiver exploits CSI information to locate a person, superimpose on frames a copy of the same frame signal whose goal is not destroying reception as in jamming, but only obfuscate the location-relevant information carried by the CSI. A prototype implementation and early results look promising; they show the feasibility of location obfuscation with high efficiency and excellent preservation of communication performance, and indicate that the technique works both against passive attacks, where the attacker controls only a receiver, and active ones, where he/she controls both a transmitter and a receiver. These results pave the road for further research on smart spaces that preserve users’ privacy with a technical solution and not only via legal prescriptions

Integrating CSI Sensing in Wireless Networks: Challenges to Privacy and Countermeasures

The path toward 6G is still long and blurred, but a few key points seem to be already decided: integration of many different access networks; adoption of massive MIMO technologies; use of frequencies above current radio spectrum up to THz and beyond; and inclusion of artificial intelligence and machine learning in standard management and operations. One additional point that is less discussed, but seems key for success, is the advanced use of channel state information (CSI) for both equalization and decoding purposes as well as for sensing ones. CSI-based sensing promises a plethora of new applications and a quantum leap in service personalization and customer-centric network management. At the same time, CSI analysis, being based on the physical characteristics of the propagated signal, poses novel threats to people's privacy and security: No software-based solution or cryptographic method above the physical layer can prevent the analysis of CSI. CSI analysis can reveal people's position or activity, allow tracking them, and discover details on the environment that today can be seen only with cameras or radars. In this article, we discuss the current status of CSI-based sensing and present some technologies that can protect people's privacy and at the same time allow legitimate use of the information carried by the CSI to offer better services

On the Implementation of Location Obfuscation in openwifi and Its Performance

Wi-Fi sensing as a side-effect of communications is opening new opportunities for smart services integrating communications with environmental properties, first and foremost the position of devices and people. At the same time, this technology represents an unprecedented threat to people’s privacy, as personal information can be collected directly at the physical layer without any possibility to hide or protect it. Several works already discussed the possibility of safeguarding users’ privacy without hampering communication performance. Usually, some signal pre-processing at the transmitter side is needed to introduce pseudo-random (artificial) patterns in the channel response estimated at the receiver, preventing the extraction of meaningful information from the channel state. However, there is currently just one implementation of such techniques in a real system (openwifi), and it has never been tested for performance. In this work, we present the implementation of a location obfuscation technique within the openwifi project that enables fine manipulation of the radio signal at transmitter side and yields acceptable, if not good, performance. The paper discusses the implementation of the obfuscation subsystem, its performance, possible improvements, and further steps to allow authorized devices to “de-obfuscate” the signal and retrieve the sensed information

MRP transporters and low phytic acid mutants in major crops : main pleiotropic effects and future perspectives

Phytic acid (PA) represents the major storage form of seed phosphate (P). During seed maturation, it accumulates as phytate salts chelating various mineral cations, therefore reducing their bioavailability. During germination, phytase dephosphorylates PA releasing both P and cations which in turn can be used for the nutrition of the growing seedling. Animals do not possess phytase, thus monogastric animals assimilate only 10% of the phytate ingested with feed, whilst 90% is excreted and may contribute to cause P pollution of the environment. To overcome this double problem, nutritional and environmental, in the last four decades, many low phytic acid (lpa) mutants (most of which affect the PA-MRP transporters) have been isolated and characterized in all major crops, showing that the lpa trait can increase the nutritional quality of foods and feeds and improve P management in agriculture. Nevertheless, these mutations are frequently accompanied by negative pleiotropic effects leading to agronomic defects which may affect either seed viability and germination or plant development or in some cases even increase the resistance to cooking, thus limiting the interest of breeders. Therefore, although some significant results have been reached, the isolation of lpa mutants improved for their nutritional quality and with a good field performance remains a goal so far not fully achieved for many crops. Here, we will summarize the main pleiotropic effects that have been reported to date in lpa mutants affected in PA-MRP transporters in five productive agronomic species, as well as addressing some of the possible challenges to overcome these hurdles and improve the breeding efforts for lpa mutants

The EASEL project: Towards educational human-robot symbiotic interaction

This paper presents the EU EASEL project, which explores the potential impact and relevance of a robot in educational settings. We present the project objectives and the theorectical background on which the project builds, briefly introduce the EASEL technological developments, and end with a summary of what we have learned from the evaluation studies carried out in the project so far

Assessment of Hermetia illucens larvae performance reared on raw or contaminated peanut by-products with Aspergillus flavus and Fusarium graminearum

The peanut supply chain is characterised by a high production of by-products, mainly shells and small pods, often discarded by processing companies. However, the richness of nutritive substances makes these products valuable as feed substrates for Hermetia illucens larvae rearing. Therefore, the aims of this work were to (1) evaluate the performance of H. illucens larvae reared on peanut by-products and (2) study the effect of various levels of fungal contamination in by-products on H. illucens larvae performance, focusing on growth and mortality. Two agro-industrial peanut by-products (rich by-product, R; poor by-product, P) were ground and mixed in different percentages (0-100%, step 10%) to obtain 11 different feeding substrates, then rehydrated to 70% moisture. Three different trials were conducted using these substrates, with three-day-old H. illucens larvae reared for 10 days. Whereas, the effect of fungal contamination was investigated by inoculating chicken feed (standard, S) and substrate P5R5 (50% P and 50% R) with two spore suspensions (Aspergillus flavus and Fusarium graminearum, 105 spore/mL), at three different inoculation times (5, 3 and 0 days before the addition of larvae). The substrate composition considerably impacted larval growth, with the highest larval weight increase obtained when R reached 50% in the substrate. Fungal contamination in by-products significantly reduced larvae performance, with a stronger negative effect from A. flavus. These findings suggest the potential for enhancing peanut by-products as a rearing substrate for H. illucens larvae, although the composition and the possible fungal contamination may reduce the effectiveness of the process

Design of an Acoustic Luneburg Lens via Topology Optimization of Pentamode Lattice

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Pyrethroid resistance in Italian populations of the mite Varroa destructor: a focus on the Lombardy region

Varroa destructor Anderson et Trueman (Acari Varroidae) is a major pest of honey bees and synthetic acaricide treatments remain the most effective tool to contain its infestations. In 1991, pyrethroid resistance was first reported in Lombardy, and is now spread worldwide. Recently, three different mutations (L925V/I/M) occurring in the voltage-gated sodium channel have been associated with tau-fluvalinate resistance. Furthermore, in the literature, indirect evidence from laboratory bioassays have indicated that high levels of esterases may be involved in mites resistant to tau-fluvalinate. This study provides an update on the actual spread of target-site resistance to tau-fluvalinate in V. destructor samples collected in the Lombardy region. TaqMan assays showed that mutation L925V is present in this area, however only low frequencies of this resistant allele were detected. The majority of resistant mites were found in the homozygous form (11%), and only a small fraction possessed the heterozygous genotype (2%). Additionally, a protocol was set up to detect esterase activity directly in single mites. Slight variability was observed among different populations collected in Lombardy. Additional studies are needed to confirm the involvement of esterases in resistance to pyrethroids in V. destructor and whether this can be correlated to changes in enzyme activity