Showing papers in "Journal of Communications in 2019"

Improving Characteristics of 28/38GHz MIMO Antenna for 5G Applications by Using Double-Side EBG Structure

Abstract: — Multiple Input Multiple Output (MIMO) antenna is expected to form a major technique of 5G communication to get a high channel capacity. However the antenna performance is degraded significantly because of mutual coupling between close elements in portable equipments. In this paper, a novel EBG structure for 28/38GHz dual-band MIMO antenna with its equivalent is proposed. Having round shape and double side design, the proposed double-side EBG (DS-EBG) structure is able to improve significantly both mutual coupling and gain without any decoupling structure between antenna elements. Thus the MIMO antenna gets compact size of 15.3x8.5x0.79mm with no distance between antenna elements from edge to edge. The antenna radiation efficiency is also refined at both bands. This improvement has not attained from any previous EBG structure studies. At 28GHz, the radiation efficiency is increased from 83.2% to 87.6% while it is raised from 83.1% to 91.1% at 38GHz. Besides, the antenna achieves wide bandwidth of 7.1% and 13.16% at 28GHz and 38GHz, respectively that is suitable for 5G terminals. All dimensions of EBG cell as well as antenna are optimized by using Computer Simulation Technology (CST) software.

Power Allocation in Cooperative NOMA MU-MIMO Beamforming Based on Maximal SLR Precoding for 5G

Abstract: — Cooperative Non-orthogonal multiple access (NOMA) is an effective solution to prevent the degradation in performance of the far users, by allocating less power to users with better channel conditions. The challenge for the base station is to decide how to allocate the power among the individual information waveforms, so we proposed cooperative NOMA in downlink MU-MIMO beamforming based on the signal to leakage ratio (SLR), to achieve power domain between the superposition users signal. We aim to minimize the total transmit power by exploiting the solution of the maximal signal to leakage ratio (maximal-SLR) for each user to find the minimum transmit power per user. sequentially, the best user’s channel will assigned in the first-time slot channel because there is a better channel for each user when the precoder with less transmits power. Order Successive Interference Cancellation (OSIC) and Maximum-likelihood (ML) estimator method are employed at the receiver. Rician fading channels are considered as second-time slot channel. Bit error rate (BER) performance evaluations show that the minimizing the total transmitted power in cooperative NOMA beamforming based on maximal-SLR scheme (MinP-NOMA-MaxSLR) (proposed scheme) is outperforming cooperative NOMA beamforming based maximal-SLR (NOMA-MaxSLR).

Impact of Apodization Profile on Performance of Fiber Bragg Grating Strain–Temperature Sensor

Abstract: —This work uses simulation software OptiGrating and OptiSystem to present the apodization effect on the performance of Fiber Bragg Grating (FBG) that is based on a strain– temperature sensor. Two FBGs with different center frequencies were designed via OptiGrating and then exported to OptiSystem to examine the impact of different apodization profiles on the sensing capability of the FBG. The apodization techniques include uniform, Gaussian, hyper-tanh, and sinc. Strain and temperature can be measured separately via the proposed system within 0.84 μm/μstrain and 14 pm/C, respectively.

A New Fuzzy-TOPSIS based Algorithm for Network Selection in Next-Generation Heterogeneous Networks

Abstract: — The overuse of next-generation wireless networks such as 4G and future generations has made the appearance of the vertical transfer to allow mobile users to move between different heterogeneous networks at any time and anywhere. This rapid evolution of wireless communication technologies imposes an improvement of the quality of service (QoS) in order to keep the user Always Best Connected (ABC). The purpose of this paper is to discuss the trouble of network selection employing the multi-attribute decision-making (MADM) methods to improve decision making at the time of a vertical handover. We propose a network selection approach based on the enhancement of the Fuzzy technique for order preference by similarity to the ideal solution (FTOPSIS) algorithm, applied to classify the available networks. Afterwards Fuzzy analytic hierarchy process (FAHP) method used to obtain the weights of Criteria. Implementation and simulation experiments are presented to evaluate our proposed approach. The factual results show that our FE-TOPSIS algorithm outperforms the classic FTOPSIS algorithms.

Experiences on Evaluating Network Simulators: A Methodological Approach

Abstract: There exists a variety of network simulators, used to imitate the protocols, nodes, and connections in data networks. They differ in their design, goals, and characteristics. Thus, comparing simulators requires a clear and standardized methodology. In this paper, based on a set of measurable and comparable criteria, we propose an approach to evaluate them. We validate the suggested approach with two network simulators, namely Packet Tracer and GNS3. In that regard, a test scenario is put forward on the two simulators, both in Linux and Windows environments, and their performance is monitored based on the suggested approach. This paper does not propose a method for selecting the best simulator, but it rather supplies the researchers with an evaluation tool, that can be used to describe, compare, and select the most suitable network simulators for a given scenario.

An improved indoor location technique using combination of kalman filter and centroid positioning

Abstract: —Indoor positioning technique is used to trace the location of entities within a non-space environment riding from the incapability of GPS to do so. Most of indoor localization techniques proposed by researchers to discover an optimized solution for indoor location tracking that has high precision and accuracy. This paper proposes an improved indoor location technique by implementing Trilateration and Kalman Filter that can manipulate noise signal reduced from raw Received Signal Strength Indicator (RSSI). This paper also proposed the uses of Centroid Positioning that be amended on top of Kalman Filter which to study whether it can improve the accuracy rate or not. Upon implementing the technique, observation and comparison are made to measure the effectiveness and reliability of the uses of Kalman Filter and Centroid Positioning. Our analysis and finding show that the enhanced indoor positioning technique has improved the accuracy tremendously.

An IP Multicast Framework for Routable Sample Value Communication in Transmission Grids

Abstract: —The growth and deployment of digital substations based on IEC 61850 in power utility industry will spawn new opportunities for wide area systems. These include monitoring, protection and control applications that will require suitable communication architectures and technologies. Techniques such as bridging and tunneling have been recommended for encapsulating and de-encapsulating messages between substations. These methods are however point-to-point solutions and are not suitable for wide area applications, involving multiple substations at the same time. In this paper, we propose using Protocol Independent MulticastSource Specific Multicast (PIM-SSM), an IP multicast routing protocol for routable Sampled Value transmission in decentralized wide area systems. IP multicast is a technology tailored for one-to-many and many-to-many communications, such as wide area protection applications requiring multiple substations receiving R-SV messages in a single transmission from another substation in the power grid. We first show how PIM-SSM can be realized in a transmission grid communication network and present a qualitative analysis of effects on multicast when link failures occur. We then present a quantitative study to evaluate the performance of PIM-SSM, on selected communication network topologies. Our results show that the communication technology will play a critical role in efficient delivery of routable Sampled Value data in a multicast framework. Furthermore, they show that improvements in the networking infrastructure design leads to better performance of the multicast delivery.

A new approach for machine-tool architecture selection at preliminary design stage

Abstract: Productivity and quality requirements in the aerospace industry involve optimized machine-tools in terms of stiffness, precision, kinematics and dynamics. Many researches aiming at evaluating and optimizing machine-tool performances in the preliminary design stage have been carried-out. This paper presents a new approach for selecting the best appropriate machine-tool architecture, for a given application, based on optimizing conceptual design models. In fact, considered machine-tool structures are modeled with simplified shape parts. The dimensions of these parts are defined as design variables. Afterward, a parametric design optimization is performed for each considered architecture, in order to minimize its total mass under the constraint of a minimal attempted stiffness all over the workspace. After that, several architectures can be compared and classified according to performance indices computed from the mechanical behavior of their corresponding optimized structures. This approach allows restricting the total number of structural arrangements to be detailed further and analyzed more accurately. The paper includes an illustration of the proposed approach through a comparative study between an open-loop and a closed-loop machine-tool architectures.

Analysis of Energy Consumption and Evaluation of Metric Parameters of Routing Protocols in Ad hoc (MANET) Networks Using: NS2 Simulator

Abstract: —MANET networks represent a technological revolution in measurement instruments resulting from the convergence of miniaturized electronic systems and wireless communication systems. Despite the many advantages of wireless sensor networks in many areas, they have many problems such as managing the power consumption of mobile devices, selecting the routing protocol, limiting bandwidth and the shortest path. In order to guarantee a good quality of service, to ensure the routing of the information and to prolong the lifetime of the entire network, the analysis of the performances of the protocols is the main step to make before selecting a particular protocol. Therefore, the selected protocol should have the best results in terms of delivery and data integrity. Indeed, the purpose of our experiments is to examine and quantify the effects of various factors and their interactions on the overall performance of ad hoc networks. This article presents a performance analysis of three types of routing protocols namely, OLSR, TORA, and ZRP, which are evaluated and simulated according to a well-defined scenario using the NS2 simulator. The results of the simulation give a better performance of the protocols studied according to the packet delivery rate, the average end-to-end delay, and the throughput.

Throughput measurement and estimation model for concurrent communications of multiple raspberry pi access-points in wireless local-area network

Abstract: —Recently, Raspberry Pi has become popular around the world as an inexpensive, small, and powerful computing device. We have studied its use as the software access-point (AP) for the IEEE 802.11n wireless local-area network (WLAN), where the channel bonding (CB) can increase the throughput by bonding two channels into one. However, the built-in wireless network interface card (NIC) adapter fails to support the CB. Thus, we have configured the CB using external NIC adapters, and investigated the throughput performance and estimation model for only one link between a PC host and a Raspberry Pi AP. In this paper, we present the throughput measurement for concurrent communications of multiple links with up to three APs under different adapters and channels with 11 and 13 partially overlapping channels (POCs) at 2.4GHz. Besides, we extend the throughput estimation model by introducing the throughput drop factor to consider interferences between the links. This factor can be derived from the CB use and the assigned channels for the links. The effectiveness of the proposal is verified by comparing the estimated throughput with the measured one.

A Game-theoretic Approach to Device and Resource Discovery in Internet of Battle Things

Abstract: —This paper investigates the problem of optimizing automated supply support operations in the Internet of Battle Things. Such networks have highly dynamic environments and decision making in hindered by the big data volume, velocity, and variety. The literature for automation in the Internet of Battle Things lacks a decision-making model for this crucial logistic task. A solution is proposed based on coalition game theory. The problem of responding to supply support requests is formulated as a coalition game of selecting the best group of cargo supply vehicles, to respond to supply support requests in a region of the battlefront. Through the principles of coalition formation, a coalition selection and region assignment algorithm are designed to form coalitions for optimizing resource allocation and maintaining a high level of request satisfaction.

Is “Outperform” Still Appropriate to Qualify the Simulation Results of Proposed Protocols for WSNs?

Abstract: —Wireless Sensor Networks (WSNs) are the subject of many proposals to improve performance in terms of data delivery ratio, end-to-end delay and energy consumption. To estimate the validity and performance of these proposals, comparisons with the existing protocols are made via simulation tools such as NS2/3, OMNeT++, Glomosim, OPNET, etc. It is interesting to note that in a multitude of scientific articles we can read a variant of: “our proposed protocol outperforms..., ” in the conclusions. This type of conclusion is used even when the simulations only find an increase of a few percent. Although it is not false this statement should be interpreted differently. In this paper we will show, by a comparison of two MAC protocols, and two routing protocols, that the choice of simulation parameters can have a much stronger influence than a gain of a few percent. Thus, we will try to demonstrate that the word ”outperforms” is dependent on the conditions of simulations that are very often only partially specified in the articles. This analytical study allows us to suggest that, it would be more judicious at first to completely detail the simulation environment and to conclude instead of ”our proposed protocol outperforms ...” by ”for the simulation set precisely defined in part xx of this contribution ... ”. In addition, if the simulation conditions are clearly specified, they will be reproducible and make the comparison of results with other protocols easier and more accurate.

Performance analysis of MIMO techniques in LTE

Abstract: —In today’s world broadband cellular communication has a vast variety of applications. Some of them include HD video streaming, web browsing, social media and mobile banking. These applications provide opportunities for both network operators as well as consumers. Since these applications consume very large data, mobile operators face tough challenges to deliver bandwidth to the subscribers. Mobile operators invest profoundly to acquire bandwidth in the radio frequency spectrum with an aim to increase the capacity of wireless networks. Despite this fact, the radio frequency spectrum in not an infinite resource, as the whole telecommunication industry is battling a spectrum crisis. Hence, newer technologies such as LTE have evolved with an aim to produce higher throughput from prevailing bandwidth. Although LTE can deliver an increase in capacity by using the regular antenna systems, extensive deployment and optimization of Multiple-Input Multiple-Output (MIMO) antenna techniques can cause further increment in the data throughput of LTE. MIMO works the best for conditions which favor rich scattering, where signals bounce around the environment, using the radio path reflections that exist. The transmitter (Tx) and receiver (Rx) devices have more than one antenna and using the processing power available at either end of the link, they are able to utilize the various paths that are present between the two units to provide improvements in the data rates and signal to noise ratio (SNR). In order to achieve promised throughputs in LTE systems, operators must optimize their networks’ multipath conditions for MIMO, targeting both rich scattering conditions and high SNR for each multipath signal. Even so, MIMO antenna techniques bring along with them their own distinctive challenges, calling for a newer approach towards measurement and optimization of these networks. This project aims to improve the capacity of LTE networks by implementing MIMO technology in these networks, using software simulation.

An Optimal Allocation of Tracking Tasks in a SW/HW Fog/Cloud Based Distributed Video Surveillance System

Abstract: In this paper we propose a novel and systematic approach for dynamic allocation of tasks in a video surveillance system using smart cameras and based on Cloud/Fog architecture. Tracking tasks arrive in the system in a random way and must be assigned to the available devices (cameras, Fog nodes and the Cloud). Our approach guarantees the best solution optimizing power consumption and communication cost over the system. The proposed methods uses an integer programming model and its effectiveness is shown on an application example.