Статьи журнала - International Journal of Wireless and Microwave Technologies
Все статьи: 532
IPv6 Migration Strategy Using Carrier Grade Network Address Translation
Статья научная
Due to the increased strain each new Internet-connected item puts on the IPv4 infrastructure, the emergence of additional Internet-connected places and devices has accelerated IPv4 exhaustion. Service providers have been obliged to invest in infrastructure to handle greater traffic due to unexpected growth in subscribers and linked IoT devices. Service providers are struggling to maintain growth and business continuity due to the expiration of IPv4 globally and the adoption of IPv6. There is strongly a need to address both a short-term solution for the maintenance of their current IPv4 address allocation and a long-term solution for a seamless transition to an IPv6 infrastructure, various service providers will need to design an address translation strategy. This paper presents a solution using CGNAT towards the migration of IPv6 networks. A general overview of the various parts needed to manage the depletion of IPv4 addressing and the engagement of full carrier grade network address translation solution is also discussed in this paper along with the different types of NAT.
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Identifying Protein Structural Classes Using MVP Algorithm
Статья научная
A new method for the prediction of protein structural classes is constructed based on MVP (Maximum variance projection) algorithm, which is a manifold learning-based data mining method. DC (Dipeptide Composition) and PseAA (Pseudo Amino Acid) are used as conditional attributes for the construction of decision system. A DR (Dimensionality Reduction) algorithm, the so-called MVP is introduced to reduce the decision system, which can be used to classify new objects. Experimental results thus obtained are quite encouraging, which indicate that the above method is used effectively to deal with this complicated problem of protein structural classes.
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Identifying Sentiment in Web Multi-topic Documents
Статья научная
Most of web documents coverage multiple topic. Identifying sentiment of multi-topic documents is a challenge task. In this paper, we proposed a new method to solve this problem. The method firstly reveals the latent topical facets in documents by Parametric Mixture Model. By focusing on modeling the generation process of a document with multiple topics, we can extract specific properties of documents with multiple topics. PMM models documents with multiple topics by mixing model parameters of each single topic. In order to analyze sentiment of each topic, conditional random fields techniques is used to identify sentiment. Empirical experiments on test datasets show that this approach is effective for extracting subtopics and revealing sentiments of each topic. Moreover, this method is quite general and can be applied to any kinds of text collections.
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Impact of Mobility on MANETs Routing Protocols Using Group Mobility Model
Статья научная
The MANET routing protocols should be tested under realistic conditions of the network including various parameters such as network size, representative data traffic models, realistic movements of the mobile users, etc. Many factors impinge the performance evaluation of MANETs routing protocols. Mobile nodes are communicated with each other with the help of routing protocols. Unpredictable movement of a mobile node affect the routing information which directly interrupt the subsist communication. A mobility model is used to depict the realistic movements of mobile nodes in the designed scenario. In this study the group mobility model has been used to deploy the mobility effect in the scenario. The goal of this paper is to investigate the impact of group mobility on performance of routing protocols under group mobility model using QualNet simulator. In the paper it is illustrate that how the performance results of an ad hoc network protocol drastically change with the increasing node density.The various scenarios investigated with varying density of nodes in groups. Performance analysis is carried out on the basis of performance metrics under group mobility model. The outcome of this work shows that mobility has a detrimental impact on the performance of routing protocols. From the simulation results, it is shown that the DSR protocol clearly outperform all other routing protocols with increasing node density under group mobility model.
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Impact of Wall Coating on the Behavior of Indoor OWC under Diffuse Topology
Статья научная
Optical wireless communication (OWC) is an innovative technology that is gaining more attention as the demand for capacity continues to increase. It is one of the most promising alternative technologies for indoor and outdoor applications. In this paper, the effect of the inner wall coating material, color and roughness on the performance of OWC system implementing single-diffuse topology is studied. A new procedure is proposed to generate a rough surface model with predetermined statistical properties to simulate the matte painting material on the internal walls of a room. Additionally, a new technique that applies the geometrical theory of diffraction (GTD) in conjunction with a ray tracing (RT) scenario is developed to evaluate the scattered optical beam due to a primary ray incident on a Lambertian surface. The performance of the single-diffuse OWC strategy is assessed by investigating some important performance measurements such as signal strength and the bit error rate (BER) due to unavoidable ambient light which is modeled as an additive white Gaussian noise. It is shown that the surface roughness of the matte painting on the Lambertian diffuse surface has a major effect on the indoor OWC system performance.
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Implementation of a Locator-Based Route Switching Scheme for Improved Routing in Proxy Mobile IPv6
Статья научная
Proxy Mobile IPv6 (PMIPv6) is a promising IP mobility protocols that is being deployed in emerging wireless technologies. This however has a non-optimal packet route as a result of the triangular routing problem. This creates a bottle neck at the Local Mobility Anchor (LMA) thereby increasing packet delays. This paper presents the implementation of a locator-based route switching scheme on OPNET Modeler. The Mobility Access Gateway (MAG) and the LMA were enhanced by making them intelligent. This enables them to be able to check the position of the Corresponding Node (CN) with respect to the Mobile Node (MN) and also determine the available bandwidth on each link. From the checks made, a three-stage decision process is used to switch routing to the most optimal route that guarantees the best QoS. Node Models were developed for the MAG and LMA, network models were deployed and simulation tests were carried out. The results show that the developed scheme switched packets to a more optimal route according to the designed algorithm. The impact of this switching on differences between transmitted throughput at MN and the received throughput at CN was also evaluated. The receiver activity result shows a reduction in the bottleneck at the LMA-MAG link. The end-to-end delay results show over 50 milliseconds drop in packet delay as a result of the switching to a more optimal route. This shows that the packet delays result from the congestion at the LMA-MAG interface due to suboptimal routing.
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Implementing Video OCR along with SWT Technique for Video indexing and Analysis
Статья научная
The main purpose of this paper is to expand the usage of OCR (Optical character recognition) as this is only implemented over images and to extend this Video OCR is introduced in a way to help to retrieve the information from the video without playing the video. Video OCR is executed with the assistance of OpenCv2 module and PyTesseract [7] at the side of SWT approach which all pretty collectively make an ideal aggregate to offer an appropriate content from the video (i.e., Lecture video or any kind of video which has slides or text on the background of the video) [2,4].This technique is performed in a well-designed along with easy steps to provide us an correct end result of the facts from the video into textual files. In addition to this we also added Speech Recognition module within the project to support the video along with the text file. This speech delivered by the faculty (i.e., instructor/educator/teacher), or an educator will be also resulted in a text file.
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Improved Route Discovery Scheme under Blackhole Attack in MANET
Статья научная
A Mobile Ad Hoc Network (MANET) consists of numerous wireless mobile devices. It is a self-organizing network and does not require any pre-established infrastructure. Communication between devices sets up without any dedicated centralized server. A malicious node takes advantage of this vulnerability and attempts to integrate into the network in order to lower its overall performance. In MANET, one of the most dangerous types of attacks is the blackhole node assault. In order to join the route, a node with blackhole assault wrongly sends route information to the source node during the route discovery process and degrades the network performance. In order to address this problem, a novel Blackhole Detection Algorithm (BHDA) has been proposed in this work. To determine the existence of blackhole nodes, the protocol takes into account various factors including number of route request packets (RREQ) received, number of RREQ packets forwarded, and number of route reply packets (RREP) transmitted by nodes throughout the route discovery process. Apart from this, each node maintains a local neighbourhood information and for that all neighbourhood node has to pass the check before becoming a neighbour. The simulation results prove that the proposed technique BHDA shows drastic improvement in network performance under blackhole attack.
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Статья научная
The design of a double layer stacked microstrip loop shaped patch antenna for multiband operation has been proposed. The design has been evolved following the iterations of a rectangular patch and a single layer loop patch structure. The material considered for the substrate of both the layers is 1.6 mm thick FR4 epoxy and the feeding technique used for the bottom patch is coaxial/ probe feed. The radiations from the bottom layer patch have been electromagnetically coupled to the upper layer patch. The main results including the reflection coefficient, bandwidth, radiation pattern, gain, directivity and VSWR for single frequency operation in each case have been discussed separately and finally compared. The comparison shows that the proposed stacked structure is clearly advantageous over the conventional rectangular patch and the single layer designed prototype in terms of the standard parameters that have been obtained. The three stage designs are useful to serve the X-band aviation applications including radio location and fixed mobile radio location.
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Improvement of ZigBee Using by Thread and Backpressure Algorithm
Статья научная
In wireless sensor networks, two approaches of tree and mesh routing are introduced to determine the path of packets during the transition process. Tree routing is a simple routing protocol with low overhead that in this protocol father-child bonds for packet transmission from the source to the destination is used. The biggest problem of routing is the increase of the number of mutations in comparison with other routing protocols. In order to improve this problem, protocols have been introduced in recent years to determine a shortcut path on the basis of the tree routing. This study is an attempt to analyse and evaluate the existing routing algorithms, identify and overcome their disadvantages, also in some other protocols, only reducing the number of mutations has been discussed. However, to achieve this goal leads to increased energy consumption and thus reducing the lifetime of the network; reducing the number of mutations is an important parameter and can reduce delays in the network, however, it should be noted the energy consumption in ZigBee networks is a very important debate. Besides that, this study will try—in addition to reducing the average number of mutations—to reduce the traffic load near the root node in the proposed algorithms. As a result, on the one hand, the application of this algorithm in ZigBee networks reduces delays and on the other hand, will also lead to balancing of load and energy in the network. Using this algorithm, the scope and lifetime of the proposed protocol-based networks can be increased.
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Статья научная
Wireless sensor network has many applications and very active research area. The coverage span of this network is very important parameter where wide coverage area is a challenge. This paper proposes an architecture for large-scale wireless sensor network (LSWSN) based on satellites and the High-Altitude Platforms (HAP) where the sensor nodes are located on the ground and a wide coverage sink station may be in the form of a satellite or a network of HAPs. A scenario is described for multilayer LSWSN and a study for the system requirements has been established showing the number of Satellites, HAPs and coverage per each sink according to the elevation angle requirements. The Satellite-HAP-Sensor multilayer LSWSN architecture has the feasibility for effective energy and earth coverage and is optimum for covering largely sparse regions.
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Integrated Guard Channel Synthesis in AESA based Airborne Surveillance Radar
Статья научная
The guard channel is very effective in eliminating side-lobe returns, both targets and discrete clutter, in airborne radar's. The ideal design criterion for the guard channel is that all the side lobes of the main antenna are covered by the guard pattern. In this paper a novel design approach of generating the guard using the elements of the main Active Electronically Scanned Array (AESA) antenna, thereby eliminating the need for a separate antenna, is presented. The ground clutter has an angle dependent Doppler and clutter discrete that leak in through the side lobes, especially the inter-cardinal elevation side lobes looking at the near range, needs to be eliminated. Towards this the design of the weighting coefficients for the guard to cover all the side lobes of the main array is discussed. Furthermore a digital threshold scheme is proposed to improve the effectiveness of guard channel in eliminating side-lobe returns. The detection loss and blanking probability are characterized for the design. The measurement results confirm that the design objectives are met.
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Intelligent and Distributed Localization of Nodes in Wireless Sensor Networks
Статья научная
In wireless sensor networks, the issue of nodes localization has taken a wide area of research. Most applications need to know the position of sensor nodes for reasons of optimal and fast data routing. In this paper, a new distributed localization algorithm based on Self Organizing Maps (SOMs) is proposed to determine the location of a node in a wireless sensor network. The proposed algorithm is classified as a range-free algorithm which uses only the connectivity information between nodes without the need to measure the time of arrival or signal strength as range-based algorithms require. It utilizes the neighborhood information and the well-known anchors' positions to calculate the estimated locations of nodes. Our algorithm is made up of two main stages. The initial estimated locations of nodes are calculated in the initialization stage, and fed to the learning stage in which a SOM is used to calculate the final estimated locations of nodes. By using the neighborhood information at the first stage, the algorithm has significantly reduced the SOM learning time and the number of iterations to converge. On the other hand, starting with real data rather than random data maximized the accuracy of the resulted locations. Furthermore, the distributed implementation of the algorithm highly alleviated the pressure on the wireless nodes which are characterized with low power and limited capabilities. The proposed algorithm has been implemented using MATLAB software and experimented by deploying different number of nodes in a specific area with different communication radio ranges. Extensive simulations evidently verified the performance of the algorithm and achieved a very good accuracy. Moreover, the algorithm proved its effectiveness with a lower average error and lower number of iterations compared to other related algorithms.
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Статья научная
In this paper, we present atmospheric effect on 5th Generation (5G) millimeter wave (MMWave) communication system. Atmospheric effects for Delhi (India) based 5G communication system is calculated as per Delhi atmospheric conditions. Atmospheric impairments are major cause of degrading mmWave signal power while mmWave propagation in wireless channel. Due to Atmospheric impairments attenuation takes place and major impairments are like water vapour, oxygen, rain and fog for Delhi (India). 5G mmWave attenuation calculations are performed for the mmWave band frequencies 28 GHz, 37 GHz and 39 GHz. In this paper intelligent adaptive transmitter based on trend of the atmospheric conditions tunes to machine learning (ML) based derivation of channel capacity. The ML based transmitter is a supervised ML device and it has provision of self teaching learning machine based on data. Results are graphed for the mentioned frequencies and also intelligently software defined (SD) Shannon channel capacity calculated for Delhi (India) based 5G mmWave communication system under different atmospheric conditions.
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Interference Mitigation Techniques for Spectral Capacity Enhancement in GSM Networks
Статья научная
Random Frequency Hopping (FH) is a key feature of GSM networks that allows for capacity enhancement. The increased co-channel interference experienced in networks with tight frequency reuse schemes can be mitigated by adopting frequency hopping. Frequency hopping diversifies the interference signals over sparse transmitted bursts. This effect is called Interference Diversity. Interference Diversity allows the Forward Error Correcting codes (FEC) to easily correct the corrupted bits. Thus, frequency hopping allows the network operator to use a tighter frequency reuse scheme without exhibiting higher levels of co-channel interference. Discontinuous Transmission (DTX) is another interference mitigation method that utilizes the user’s silence frames to reduce the transmitted power, while Power Control (PC) links the transmitted handset power with its relative distance from the Base Station (BTS). In this work, we study the impact of random FH, DTX and PC on the Spectral Capacity of GSM cellular networks by means of combined link level and system level simulation. It is shown that a spectral capacity gain is obtained in a 3/9 reuse scheme that deploys PC, DTX and FH compared to a conventional 4/12 reuse scheme.
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Interference Mitigation in Wireless Communication – A Tutorial on Spread Spectrum Technology
Статья научная
This paper focuses on Spread Spectrum technique and its interference mitigation feature as applied in wireless communication. With spread spectrum technology it is possible to implement the transmission of multiple signals over wider ranges of spectrum without resulting to interference from other signals transmitted over the same frequencies. It does this by rejecting any received signal that does not carry the proper code. Interference rejection, one of the several features of spread spectrum technology is a difficult concept to understand. It is therefore proper to x-ray this topic in a less complex manner so that it can be well understood by those who are not mathematically grounded. In view of this a further simplified approach in presenting this subject is necessary. A tutorial approach is used to simplify this subject for better understanding and how this feature is used in Code Division Multiple Access (CDMA) systems. To show how multipath interference rejection is achieved in CDMA systems simple equations and schematics were used. The discussions cover the method of code recognition at the receiver which serves as a technique for interference mitigation. The paper helps to understand the theory of code recognition in Spread Spectrum, and thus provides answer to the question on how does interference mitigation or rejection in spread spectrum works?
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Interference mitigation and mobility management for D2D communication in LTE-A networks
Статья научная
Interference and Mobility management are the main parameters which affect the signal capacity and reduce the transmission efficiency for D2D communication in LTE-A networks. When the users are in the same spectrum, due to the coexistence of D2D pairs and cellular users interference management becomes a critical issue. In this paper, we introduce an interference management algorithm that maximizes the performance of D2D communication in LTE-A networks for both uplink and downlink transmissions. Optimal routing selection techniques reduce the total path distance which helps to minimize the interference and improve the overall network capacity. Mobility management is also a challenging issue in IP-mobile networks. When two DUEs change their locations from one BS to the other, handover delay calculation becomes very important to maintain the communication without interruption. In this paper we show power control techniques which helps to reduce the effect of interference and also we addressed a method for the lower delay under complex mobility issues with uninterrupted D2D communication.
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Internet Rescue Robots for Disaster Management
Статья научная
The prototype development of Rescue Robot can help search and rescue teams with their difficult and life-saving tasks. Unmanned Aerial vehicles (UAVs) and Unmanned Ground vehicles (UGVs) are viewed as two separate entities. However, upon closer examination, we can classify them into a closely-coupled system where both are just seen as separable parts of the body of one robotic entity, whose body parts can separate temporarily and acquire together again later. In this prototype, a mobile robot UGV can be used as transport and landing station for a light-weight quadcopter UAV. UAV has separable long-range vision system which provides the top view of environment for the UGV, separable images are stitched and transformed into maps and utilized for rescue operations. This rescue robot contains a combination of UGV and UAV. It is equipped with a strong manipulator arm, used for debris removal, shoring operations, and delivering medicines/ food on very rough terrain. It has light detection and ranging (lidar) sensors, cameras, enabling it to look for victims and for mapping semi-destroyed buildings. The UGV can send visual feedback to the operator at a remote location. The UAV drone has a camera for an aerial view and mapping of the place. Working in conjunction with one another and thus the human search and rescue workers, these robotic assets form a strong team, increasing the effectiveness of search and rescue operations. This project aims at the realization of a new generation of search and rescue robot which can work in semi-autonomous and wireless modes and can be used in harsh physical environments of disaster regions to hold out the given tasks more effectively by the utilization of advanced and economic sensors. the problem domain of earthquake disasters and search and rescue processes is clarified with introducing an overview of this project. Disasters unsettle the economic and social stability of society. Shortage of skilled rescue work forces, also because the risks involved in search and rescue operations, are getting foremost problems during an emergency situation. In this paper rescue robot were designed, implemented in a real time environment and analyzed the result.
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Interoperability in connected vehicles – a review
Статья научная
The introduction of automated transportation system and implementation of connected vehicle system has made interoperability even more critical than before in order to ensure effective connectivity , consistency , accuracy and reliable performance.Connected vehicles are employed with in vehicle sensor networks to collect , store , process and communicate with neighbouring vehicles to help drivers making life saving decisions. Connected vehicle systems enable the exchange of communication between a vehicle and world. Some vehicles may only receive communication, other vehicles may only send data and some may receive and send data. Hence it is essential that all systems , devices need to work together in a safe, trusted , efficient manner. Devices/Sensors embedded in vehicles follow different communication protocols as the sensors or devices are manufactured by different vendors. Hence management of coordination between devices is of much importance in Dynamic, Mobile, Heterogeneous environments such as connected vehicles. Hence, there is a need to create seamless interoperability to enable connected vehicles. It is required to enable intelligent transportation system (ITS) system/devices in Vehicles to effectively connect and communicate with other systems/devices. The adaptability of Interoperability when the devices are adhere to dynamics and mobile in nature becomes tedious and cumbersome. Solutions to interoperability is not much explored in literature. Existing interoperability solutions does not guarantee to articulate for high mobile environments such as connected vehicles where vehicles are highly mobile in nature and moving at varying speeds. The paper summarizes connected vehicles issues and challenges, current interoperability solutions, the impact of interoperability in connected vehicle scenario and demonstrates the effect of conversion time delay when exchanging data between source and destination pairs.
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Interpretable Fuzzy System for Malicious Domain Classification Using Projection Neural Network
Статья научная
In this study, we suggest an interpretable fuzzy system for the classification of malicious domains. The proposed system is integration of Sugeno type fuzzy system and projection neural network, the main advantage of interpretable fuzzy system is to classify the patterns and self-explainable capability. Whereas the projection network is used to exact mapped fuzzy inference rules to the network's projection layer. On the other hands, the system is able to deal with large amount of real-time data. The proposed model is tested malicious URL datasets collected from Alexa. The experimental results show that the system is able to classify malicious domain with high accuracy and interpretability as compared to existing methods. The proposed model is usefull to classify malicious attacks and explain the couses behind the decision. The evaluation of model based on confusion matrices, ROC and the nauck index is used for the interpretability assessments.
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