Biblio
With the rapid development of radio detection and wireless communication, narrowband radio-frequency interference (NB-RFI) is a serious threat for GNSS-R (global navigation satellite systems - reflectometry) receivers. However, interferometric GNSS-R (iGNSS-R) is more prone to the NB-RFIs than conventional GNSS-R (cGNSS-R), due to wider bandwidth and unclean replica. Therefore, there is strong demand of detecting and mitigating NB-RFIs for GNSS-R receivers, especially iGNSS-R receivers. Hence, focusing on working with high sampling rate and simplifying the fixed-point implementation on FPGA, this paper proposes a system design exploiting cascading IIR band-stop filters (BSFs) to suppress NB-RFIs. Furthermore, IIR BSF compared with IIR notch filter (NF) and IIR band-pass filter (BPF) is the merely choice that is able to mitigate both white narrowband interference (WNBI) and continuous wave interference (CWI) well. Finally, validation and evaluation are conducted, and then it is indicated that the system design can detect NB-RFIs and suppress WNBI and CWI effectively, which improves the signal-to-noise ratio (SNR) of the Delay-Doppler map (DDM).
Aiming at the incomplete and incomplete security mechanism of wireless access system in emergency communication network, this paper proposes a security mechanism requirement construction method for wireless access system based on security evaluation standard. This paper discusses the requirements of security mechanism construction in wireless access system from three aspects: the definition of security issues, the construction of security functional components and security assurance components. This method can comprehensively analyze the security threats and security requirements of wireless access system in emergency communication network, and can provide correct and reasonable guidance and reference for the establishment of security mechanism.
With the development of computer technology and the popularization of network, network brings great convenience to colleagues and risks to people from all walks of life all over the world. The data in the network world is growing explosively. Various kinds of intrusions are emerging in an endless stream. The means of network intrusion are becoming more and more complex. The intrusions occur at any time and the security threats become more and more serious. Defense alone cannot meet the needs of system security. It is also necessary to monitor the behavior of users in the network at any time and detect new intrusions that may occur at any time. This will not only make people's normal network needs cannot be guaranteed, but also face great network risks. So that people not only rely on defensive means to protect network security, this paper explores block chain network intrusion detection system. Firstly, the characteristics of block chain are briefly introduced, and the challenges of block chain network intrusion security and privacy are proposed. Secondly, the intrusion detection system of WLAN is designed experimentally. Finally, the conclusion analysis of block chain network intrusion detection system is discussed.
This paper proposes a multi-modular AC-DC converter system using wireless communication for a rapid charger of electric vehicles (EVs). The multi-modular topology, which consists of multiple modules, has an advantage on the expandability regarding voltage and power. In the proposed system, the input current and output voltage are controlled by each decentralized controller, which wirelessly communicates to the main controller, on each module. Thus, high-speed communication between the main and modules is not required. As the results in a reduced number of signal lines. The fundamental effectiveness of the proposed system is verified with a 3-kW prototype. In the experimented results, the input current imbalance rate is reduced from 49.4% to 0.1%, where total harmonic distortion is less than 3%.
Researchers and industry experts are looking at how to improve a shopper's experience and a store's revenue by leveraging and integrating technologies at the edges of the network, such as Internet-of-Things (IoT) devices, cloud-based systems, and mobile applications. The integration of IoT technology can now be used to improve purchasing incentives through the use of electronic coupons. Research has shown that targeted electronic coupons are the most effective and coupons presented to the shopper when they are near the products capture the most shoppers' dollars. Although it is easy to imagine coupons being broadcast to a shopper's mobile device over a low-power wireless channel, such a solution must be able to advertise many products, target many individual shoppers, and at the same time, provide shoppers with their desired level of privacy. To support this type of IoT-enabled shopping experience, we have designed Aggio, an electronic coupon distribution system that enables the distribution of localized, targeted coupons while supporting user privacy and security. Aggio uses cryptographic mechanisms to not only provide security but also to manage shopper groups e.g., bronze, silver, and gold reward programs) and minimize resource usage, including bandwidth and energy. The novel use of cryptographic management of coupons and groups allows Aggio to reduce bandwidth use, as well as reduce the computing and energy resources needed to process incoming coupons. Through the use of local coupon storage on the shopper's mobile device, the shopper does not need to query the cloud and so does not need to expose all of the details of their shopping decisions. Finally, the use of privacy preserving communication between the shopper's mobile device and the CouponHubs that are distributed throughout the retail environment allows the shopper to expose their location to the store without divulging their location to all other shoppers present in the store.
We propose a crypto-aided Bayesian detection framework for detecting false data in short messages with low overhead. The proposed approach employs the Bayesian detection at the physical layer in parallel with a lightweight cryptographic detection, followed by combining the two detection outcomes. We develop the maximum a posteriori probability (MAP) rule for combining the cryptographic and Bayesian detection outcome, which minimizes the average probability of detection error. We derive the probability of false alarm and missed detection and discuss the improvement of detection accuracy provided by the proposed method.
Utilization of Wireless sensor network is growing with the development in modern technologies. On other side electromagnetic spectrum is limited resources. Application of wireless communication is expanding day by day which directly threaten electromagnetic spectrum band to become congested. Cognitive Radio solves this issue by implementation of unused frequency bands as "White Space". There is another important factor that gets attention in cognitive model i.e: Wireless Security. One of the famous causes of security threat is malicious node in cognitive radio wireless sensor networks (CRWSN). The goal of this paper is to focus on security issues which are related to CRWSN as Fusion techniques, Co-operative Spectrum sensing along with two dangerous attacks in CR: Primary User Emulation (PUE) and Spectrum Sensing Data Falsification (SSDF).
Key derivation from the physical layer features of the communication channels is a promising approach which can help the key management and security enhancement in communication networks. In this paper, we consider a key generation technique that quantizes the received signal phase to obtain the secret keys. We then study the effect of a jamming attack on this system. The jammer is an active attacker that tries to make a disturbance in the key derivation procedure and changes the phase of the received signal by transmitting an adversary signal. We evaluate the effect of jamming on the security performance of the system and show the ways to improve this performance. Our numerical results show that more phase quantization regions limit the probability of successful attacks.
This paper studies the physical layer security performance of a Simultaneous Wireless Information and Power Transfer (SWIPT) millimeter wave (mmWave) ultra-dense network under a stochastic geometry framework. Specifically, we first derive the energy-information coverage probability and secrecy probability in the considered system under time switching policies. Then the effective secrecy throughput (EST) which can characterize the trade-off between the energy coverage, secure and reliable transmission performance is derived. Theoretical analyses and simulation results reveal the design insights into the effects of various network parameters like, transmit power, time switching factor, transmission rate, confidential information rate, etc, on the secrecy performance. Specifically, it is impossible to realize the effective secrecy throughput improvement just by increasing the transmit power.
Modern automotive Cyber-Physical Systems (CPS) are increasingly adopting wireless communications for Intra-Vehicular, Vehicle-to-Vehicle (V2V), and Vehicle-to-Infrastructure (V2I) protocols as a promising solution for challenges such as the wire harnessing problem, collision detection, and collision avoidance, traffic control, and environmental hazards. Regrettably, this new trend results in new security challenges that can put the safety and privacy of the automotive CPS and passengers at great risk. In addition, automotive wireless communication security is constrained by strict energy and performance limitations of electronic controller units and sensors. As a result, the key generation and management for secure automotive CPS wireless communication is an open research challenge. This article aims to help solve these security challenges by presenting a practical key generation technique based on the reciprocity and high spatial and temporal variation properties of the automotive wireless communication channel. Accompanying this technique is also a key length optimization algorithm to improve performance (in terms of time and energy) for safety-related applications constrained by small communication windows. To validate the practicality and effectiveness of our approach, we have conducted simulations alongside real-world experiments with vehicles and RC cars. Last, we demonstrate through simulations that we can generate keys with high security strength (keys with 67% min-entropy) with 20× reduction in code size overhead in comparison to the state-of-the-art security techniques.
In Ad hoc networks the main purpose is communication without infrastructure and there are many implementations already done on that. There is little effort done for security to prevent threats in ad hoc networks (like MANETs). It is already proven that; there is no any centralized mechanism for defence against threats, such as a firewall, an intrusion detection system, or a proxy in ad hoc networks. Ad hoc networks are very convenient due to its features like self-maintenance, self-organizing and providing wireless communication. In Ad hoc networks there is no fixed infrastructure in which every node works like simply a router which stores and forwards packet to final destination. Due to these dynamic topology features, Ad hoc networks are anywhere, anytime. Therefore, it is necessary to make a secure mechanism for the ad hoc components so that with flexibility they have that security also. This paper shows the secure and flexible implementation about to protect any ad hoc networks. This proposed system design is perfect solution to provide security with flexibility by providing a hybrid system which combines ECC and MAES to detect and prevent Ad hoc network attacks using Intrusion detection system. The complete proposed system designed on NS 2.35 software using Ubuntu (Linux) OS.
We present an intelligent system that focus on how to ensure the stability of ZigBee network automatically. First, we discussed on the character of ZigBee compared with WIFI. Pointed out advantage of ZigBee resides in security, stability, low power consumption and better expandability. Second, figuring out the shortcomings of ZigBee on application is that physical limitation of the frequency band and weak ability on diffraction, especially coming across a wall or a door in the actual environment of home. The third, to put forward a method which can be used to ensure the strength of ZigBee signal. The method is to detect the strength of ZigBee relay in advance. And then, to compare it with the threshold value which had been defined in previous. The threshold value of strength of ZigBee is the minimal and tolerable value which can ensure stable transmission of ZigBee. If the detected value is out of the range of threshold, system will prompt up warning message which can be used to hint user to add ZigBee reply between the original ZigBee node and ZigBee gateway.
A Mobile ad hoc network (MANET) is a set of nodes that communicate together in a cooperative way using the wireless medium, and without any central administration. Due to its inherent open nature and the lack of infrastructure, security is a complicated issue compared to other networks. That is, these networks are vulnerable to a a wide range of attacks at different network layers. At the network level, malicious nodes can perform several attacks ranging from passive eavesdropping to active interfering. Wormhole is an example of severe attack that has attracted much attention recently. It involves the redirection of traffic between two end-nodes through a Wormhole tunnel, and manipulates the routing algorithm to give illusion that nodes located far from each other are neighbors. To handle with this issue, we propose a novel detection model to allow a node to check whether a presumed shortest path contains a Wormhole tunnel or not. Our approach is based on the fact that the Wormhole tunnel reduces significantly the length of the paths passing through it.
Recently, as the age of the Internet of Things is approaching, there are more and more devices that communicate data with each other by incorporating sensors and communication functions in various objects. If the IoT is miniaturized, it can be regarded as a sensor having only the sensing ability and the low performance communication ability. Low-performance sensors are difficult to use high-quality communication, and wireless security used in expensive wireless communication devices cannot be applied. Therefore, this paper proposes authentication and key Agreement that can be applied in sensor networks using communication with speed less than 1 Kbps and has limited performances.
With the frequent use of Wi-Fi and hotspots that provide a wireless Internet environment, awareness and threats to wireless AP (Access Point) security are steadily increasing. Especially when using unauthorized APs in company, government and military facilities, there is a high possibility of being subjected to various viruses and hacking attacks. It is necessary to detect unauthorized Aps for protection of information. In this paper, we use RTT (Round Trip Time) value data set to detect authorized and unauthorized APs in wired / wireless integrated environment, analyze them using machine learning algorithms including SVM (Support Vector Machine), C4.5, KNN (K Nearest Neighbors) and MLP (Multilayer Perceptron). Overall, KNN shows the highest accuracy.