No. 1 (2019)
Published:
2019-03-30
ARTICLES FROM THIS ISSUE
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ACO-Inspired Energy-Aware Routing Algorithm for Wireless Sensor Networks
Abstract
Multi-hop networks, such as WSNs, become an object of increasing attention as an emerging technology which plays an important role for practical IoT applications. These multi-hop networks generally consist of mobile and small terminals with limited resources, which makes them vulnerable to various network status changes. Moreover, the limited nature of terminal resources available, especially in terms of battery capacity, is one of the most important issues to be addressed in order to prolong their operating time. In order to ensure efficient communications in such networks, much research has already been conducted, especially in the field of routing and transmission technologies. However, conventional approaches adopted in the routing field still suffer from the so-called energy hole problem, usually caused by unbalanced communication loads existing due to difficulties in adaptive route management. To address this issue, the present paper proposes a novel routing algorithm that utilizes ACO-inspired routing based on residual energy of terminals. Operational evaluation reveals its potential to ensure balanced energy consumption and to boost network performance.
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Adaptive Load Balancing Ad Hoc Routing Scheme Inspired by True Slime Mold
Abstract
Engineering neo-biomimetics, i.e. imitation models based on body structures and behavior of living organisms, relied upon to solve complex problems, have been studied in various fields. In distributed networks, such as ad-hoc networks and wireless sensor networks, the behavior of a variety of true slime molds which are capable of constructing multipath flow networks based on the amount of body, has been studied. Ad hoc networks only consist of mobile terminals (nodes) that can relay packets along an established route. However, link relations and the available bandwidth of the nodes change dynamically due to the mobility of nodes. In addition, the speed of communication between nodes also varies due to node positions and their communication-related quality. Thus, practical use of ad-hoc networks still remains an issue, because it is difficult to establish stable routes under such environments. This study aims to propose an adaptive load balancing routing technique that adaptively diversifies the transmission paths based on the available bandwidth, residual battery life, and the data transmission volume, by applying a mathematical model of slime mold routing, known as the physarum solver. We confirm the effectiveness of its adaptive behavior in dynamic environments using computer simulations.
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Robot Local Network Using TQS Protocol for Land-to-Underwater Communications
Abstract
This paper presents a model and an analysis of the Tag QoS switching (TQS) protocol proposed for heterogeneous robots operating in different environments. Collaborative control is topic that is widely discussed in multirobot task allocation (MRTA) – an area which includes establishing network communication between each of the connected robots. Therefore, this research focuses on classifying, prioritizing and analyzing performance of the robot local network (RLN) model which comprises a point-to-point topology network between robot peers (nodes) in the air, on land, and under water. The proposed TQS protocol was inspired by multiprotocol label switching (MPLS), achieving a quality of service (QoS) where swapping and labeling operations involving the data packet header were applied. The OMNET++ discrete event simulator was used to analyze the percentage of losses, average access delay, and throughput of the transmitted data in different classes of service (CoS), in a line of transmission between underwater and land environments. The results show that inferior data transmission performance has the lowest priority with low bitrates and extremely high data packet loss rates when the network traffic was busy. On the other hand, simulation results for the highest CoS data forwarding show that its performance was not affected by different data transmission rates characterizing different mediums and environments.
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Fuzzy Clustering with Multi-Constraint QoS Service Routing in Wireless Sensor Networks
Abstract
This paper presents a fuzzy logic-based, service differentiated, QoS aware routing protocol (FMSR) offering multipath routing for WSNs, with the purpose of providing a service differentiated path meant for communication between nodes, based on actual requirements. The proposed protocol initially forms a cluster by fuzzy c-means. Next, the building of a routing follows, so as to establish multiple paths between nodes through the modified QoS k-nearest neighborhood, based on different QoS constraints and on optimum shortest paths. If one node in the path fails due to lack of residual energy, bandwidth, packet loss, delay, an alternate path leading through another neighborhood node is selected for communication. Simulation results show that the proposed protocol performs better in terms of packet delivery ratio, delay, packet drop ratio and throughput compared to other existing routing protocols.
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Neuroplasticity and Microglia Functions Applied in Dense Wireless Networks
Abstract
This paper presents developments in the area of brain-inspired wireless communications relied upon in dense wireless networks. Classic approaches to network design are complemented, firstly, by the neuroplasticity feature enabling to add the learning ability to the network. Secondly, the microglia ability enabling to repair a network with damaged neurons is considered. When combined, these two functionalities guarantee a certain level of fault-tolerance and self-repair of the network. This work is inspired primarily by observations of extremely energy efficient functions of the brain, and of the role that microglia cells play in the active immune defense system. The concept is verified by computer simulations, where messages are transferred through a dense wireless network based on the assumption of minimized energy consumption. Simulation encompasses three different network topologies which show the impact that the location of microglia nodes and their quantity exerts on network performance. Based on the results achieved, some algorithm improvements and potential future work directions have been identified.
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Empirical Approach in Topology Control of Sensor Networks for Urban Environment
Abstract
Research into the topology control of Wireless Sensor Networks (WSNs) is geared towards modeling and analysis of methods that may be potentially harnessed to optimize the structure of connections. However, in practice, the ideas and concepts provided by researchers have actually been rarely used by network designers, while sensor systems that have already been deployed and are under continued development in urban environments frequently differ from the patterns and research models available. Moreover, easy access to diversified wireless technologies enabling new solutions to be empirically developed and popularized has also been conducive to strengthening this particular trend.
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A P2P-based Communication Framework for Geo-Location Oriented Networks
Abstract
This paper proposes a novel peer-to-peer communication framework to implement geographical location oriented networks, called G-LocON. Location-based services have been gaining in popularity, as proven by ridesharing and mobile games. Although these services have to construct geolocation oriented networks based on their users’ geographical locations, they completely rely on client/server models to communicate with neighboring terminals. G-LocON provides geolocation oriented device-to-device communication only with the current wireless technologies, such as LTE and Wi-Fi, cooperating with the global positioning system and peer-to-peer overlay networking. G-LocON will serve as a type of a mobile ad-hoc network in which devices located within the focusing area are capable of communicating directly. We developed a primitive Android application to implement the GLocON framework. Evaluation of the solution’s performance has verified the usefulness of the proposed system that offers an admissive transmission delay. Moreover, to confirm the application-related potential of the G-LocON framework, we also show a practical map software in which all neighboring mobile devices present in the focusing area are displayed.
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LoCO: Local Cooperative Data Offloading System Based on Location Information
Abstract
The development of high speed mobile networks and the widespread use of smartphones have enabled users to easily obtain large data volumes via the Internet. This causes a heavy consumption of network resources, a burden on the available bandwidth. To solve such problems, a data offloading method with a wireless LAN access point has been used to distribute traffic from mobile to fixed networks. However, the method using wireless LAN access points can only change the communication paths but cannot reduce the overall traffic. This paper proposes a local cooperative data offloading system (LoCO) that reduces the overall traffic by sharing data, with direct communication between neighbors based on their location-related information. Moreover, the authors implemented the LoCO system on Android smartphones and clarified its performance in comparison with a traditional client/server system through experiments to download data in a real-world environment.
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Rectangular Dielectric Resonator Antenna with Single Band Rejection Characteristics
Abstract
In this paper, a rectangular dielectric resonator antenna (DRA) suitable for wideband applications is presented and a band notch of WLAN (5.15–5.75) GHz is proposed. The DRA is mainly composed of a 20 × 20 mm rectangular dielectric resonator, coated with metal on the top surface, and a circular monopole excitation patch with an air gap insert. A coaxial line feed is used to excite the circular, planar monopole. An open-ended quarter wavelength C-shaped slot is embedded in the circular patch to create the notched band. The simulated results demonstrate that the proposed design produces an impedance bandwidth of more than 80%, ranging from 3.10 to 7.25 GHz for a reflection coefficient of less than −10 dB and with a band rejection at 5.50 GHz. Band notch characteristics, VSWR, and radiation patterns are studied using the HFSS high-frequency simulator and CST Studio software.
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Product of Three Random Variables and its Application in Relay Telecommunication Systems in the Presence of Multipath Fading
Abstract
In this paper, the product of three random variables (RVs) will be considered. Distribution of the product of independent random variables is very important in many applied problems, including wireless relay telecommunication systems. A few of such products of three random variables are observed in this work: the level crossing rate (LCR) of the product of a Nakagami-m random variable, a Rician random variable and a Rayleigh random variable, and of the products of two Rician RVs and one Nakagami-m RV is calculated in closed forms and presented graphically. The LCR formula may be later used for derivation of average fade duration (AFD) of a wireless relay communication radio system with three sections, working in the multipath fading channel. The impact of fading parameters and multipath fading power on the LCR is analyzed based on the graphs presented
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Enhancement of Ground-to-Aircraft Communication Using Audio Watermarking
Abstract
This paper presents research on improving the intelligibility of spoken messages transmitted to aircraft from a ground station. The proposed solution is based on the selective calling (SELCAL) system and the audio watermarking technique. The most important elements of a spoken message (commands, numerical values) are transmitted as a watermark embedded in the speech signal and are displayed to the cockpit crew. The synchronization signal is embedded in SELCAL duo-tones. The proposed system is resistant to resampling and channel noise (at SNR > 25 dB).
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Method for Determining Broadcaster Advised Emergency Wake-up Signal for ISDB-T Digital Television Receivers
Abstract
There is a way to automatically wake up television receivers when a broadcaster sends out an emergency alert. In the Integrated Services Digital Broadcasting-Terrestrial (ISDB-T) digital television standard, the emergency wake-up procedure is called an Emergency Warning System (EWS). In ISDB-T, the special signal is embedded in a control message known as transmission and modulation configuration control (TMCC). However, improper identification of the wake-up signal, often encountered in mobile reception, leads to unnecessary wake ups. In this paper, a method of reliably determining a wake-up signal is proposed by assuming that broadcasters will not change the TMCC message except for the wake-up signal when the broadcaster sends out an emergency alert. A change in the wake-up bit leads to variation parity, and the proposed method also relies on such variations. Mutual information to be obtained by the wake-up receiver is evaluated using the memoryless binary asymmetric channel model. Results showed that the proposed method provided mutual information even at a Eb/N₀ being lower than 10 dB. Mutual information of the proposed method with intermittent reception is also analyzed as a function of the duty ratio of the intermittent receiver.
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WannaCry Ransomware: Analysis of Infection, Persistence, Recovery Prevention and Propagation Mechanisms
Abstract
In recent years, we have been experiencing fast proliferation of different types of ransomware targeting home users, companies and even critical telecommunications infrastructure elements. Modern day ransomware relies on sophisticated infection, persistence and recovery prevention mechanisms. Some recent examples that received significant attention include WannaCry, Petya and BadRabbit. To design and develop appropriate defense mechanisms, it is important to understand the characteristics and the behavior of different types of ransomware. Dynamic analysis techniques are typically used to achieve that purpose, where the malicious binaries are executed in a controlled environment and are then observed. In this work, the dynamic analysis results focusing on the infamous WannaCry ransomware are presented. In particular, WannaCry is examined, during its execution in a purpose-built virtual lab environment, in order to analyze its infection, persistence, recovery prevention and propagation mechanisms. The results obtained may be used for developing appropriate detection and defense solutions for WannaCry and other ransomware families that exhibit similar behaviors
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Theoretical and Experimental Analysis of Cryptographic Hash Functions
Abstract
The paper presents a theoretical introduction to the cryptographic hash function theory and a statistical experimental analysis of selected hash functions. The definition of hash functions, differences between them, their strengths and weaknesses are explained as well. Different hash function types, classes and parameters are described. The features of hash functions are analyzed by performing statistical analysis. Experimental analysis is performed for three certified hash functions: SHA1-160, SHA2-512 and SHA3-512. Such an analysis helps understand the behavior of cryptographic hash functions and may be very helpful for comparing the security level of the hashing method selected. The tests may serve as a basis for examination of each newly proposed hash function. Additionally, the analysis may be harness as a method for comparing future proposals with the existing functions.
