Internet Wireless Communication Research Articles

3D deployment of UAV-mounted base stations for heterogeneous access requirements

Recently, unmanned aerial vehicles (UAVs) have been reported a lot as aerial base stations (BSs) to assist wireless communication in Internet of Things (IoT). However, most results for UAV deployment require uniform access requirements and obstacle-free environment. This paper considers multi-UAV-mounted BSs deployment problem in obstacle-laden environment to achieve on-demand coverage for ground user equipments (UEs), with the goal of minimizing the number of required UAVs for full coverage of all UEs by optimizing the three-dimensional (3D) positions of UAVs as well as UE clustering. On one hand, the considered problem is challenging as the constraints on the non-uniform Quality of Service (QoS) requirements, the service ability of each UAV, the beamwidth of the directional antenna equipped by each UAV and obstacle avoidance are jointly taken into account. On the other hand, these practical considerations contribute to broadening the scope of applications. We formulate the problem as a mixed-integer programming problem and develop a three-step placement algorithm to achieve the goal. First, the maximum allowed service radius of each UE is derived based on the Karush-Kuhn-Tucker (KKT) condition to satisfy required signal-to-interference-plus-ratio (SINR) threshold. Second, a greed-prior chaotic search enabled adaptive artificial bee colony (GP-CA2BC) algorithm is proposed to group the UEs such that the minimum number of required UAVs can be obtained. Third, the 3D position of each UAV is optimized to further enhance the QoS. Finally, some simulation results are presented to demonstrate the superiority of the proposed scheme in decreasing the number of required UAVs as well as improving the QoS compared with the existing works.

Performance Analysis and Optimization for Coordinated Direct and Relay Covert Transmission With Multiantenna Warder

Covert communication is crucial to ensure the safety of wireless communications in Internet of Things (IoT) systems. In this paper, a multi-antenna relay is employed to enhance the communication link and avoid the transmission being detected by the multi-antenna warder simultaneously. Considering the dynamic fluctuating fading channels of IoT systems, a novel adaptive coordinated direct and relay transmission (ACDRT) scheme is proposed where the relay switches on/off adaptively to maximize the achievable covert rate. The covertness constraint requirements are derived with instantaneous and statistical warder-related channel state information based on the availability of the channel information in practical systems. Since both the direct and the relay links impact the system performance, the optimization problem is formulated, where the beamforming vectors are coupled. A semidefinite relaxation based line search method is proposed to address this problem. Besides, the globally optimal solutions can be obtained by the proposed method, which is rigorously proved mathematically. In addition, the conditions for achieving a positive covert rate are analyzed with the multi-antenna warder. Simulations demonstrate that the performance of the ACDRT is robust to covertness requirements when the positive rate condition holds, and significant covert rate gains can be obtained by the ACDRT with the multi-antenna relay compared with the conventional systems.

Multiobjective Optimization for Improving Throughput and Energy Efficiency in UAV-Enabled IoT

Unmanned-aerial-vehicle (UAV)-aided wireless communication in Internet of Things (IoT) applications is becoming the focus of attention of researchers. This article investigates a UAV-assisted communication system for serving IoT, in which multiple rotary-wing UAVs are employed to communicate with multiple terrestrial IoT devices. Specifically, we formulate a UAV deployment multiobjective optimization problem (UAVDMOP) to simultaneously maximize the minimum throughput of the UAV–device pairs, maximize the total throughput of the whole system, and minimize the total energy consumptions of UAVs via a joint optimization of the locations of UAVs, transmission power of UAVs, and association relationship between the UAVs and IoT devices. UAVDMOP consists of both discrete and continuous solution spaces, which is difficult to be solved. Thus, we propose an improved discrete and continuous multiobjective evolutionary algorithm based on decomposition (IDCMOEA/D) with a hybrid solution initialization operation and a hybrid solution reproduction operation for increasing the performance of the algorithm so that making it more suitable for dealing with the UAVDMOP. Simulation results demonstrate that the proposed method is effective to enhance the throughput and energy efficiency of the system and it has superior performance compared to other methods.

Aerial Intelligent Reflecting Surface-Enabled Terahertz Covert Communications in Beyond-5G Internet of Things

Unmanned aerial vehicles (UAVs) are envisioned to be extensively employed for assisting wireless communications in Internet of Things (IoT) applications. On the other hand, terahertz (THz) enabled intelligent reflecting surface (IRS) is expected to be one of the core enabling technologies for forthcoming beyond-5G wireless communications that promise a broad range of data-demand applications. In this paper, we propose a UAV-mounted IRS (UIRS) communication system over THz bands for confidential data dissemination from an access point (AP) towards multiple ground user equipments (UEs) in IoT networks. Specifically, the AP intends to send data to the scheduled UE, while unscheduled UEs may pose potential adversaries. To protect information messages and the privacy of the scheduled UE, we aim to devise an energy-efficient multi-UAV covert communication scheme, where the UIRS is for reliable data transmissions, and an extra UAV is utilized as a cooperative jammer generating artificial noise (AN) to degrade unscheduled UEs detection. We then formulate a novel minimum average energy efficiency (mAEE) optimization problem, targetting to improve the covert throughput and reduce UAVs' propulsion energy consumption subject to the covertness requirement, which is determined analytically. Since the optimization problem is non-convex, we tackle it via the block successive convex approximation (BSCA) approach to iteratively solve a sequence of approximated convex sub-problems, designing the binary user scheduling, AP's power allocation, maximum AN jamming power, IRS beamforming, and both UAVs' trajectory planning. Finally, we present a low-complex overall algorithm for system performance enhancement with complexity and convergence analysis. Numerical results are provided to verify our analysis and demonstrate significant outperformance of our design over other existing benchmark schemes.

Development of an ESP-32 Microcontroller Based Weather Reporting Device

This study presents a novel approach to incorporating technology into an intelligent weather station. In recent years, the nation has experienced a decline in agricultural activities due to the change in climate causing lot of danger in the farm output; this enables the weather forecaster to actually prescribe disaster by employing the use of temperature, humidity and light sensors which senses the temperature and humidity in the atmosphere. A tipping bucket is used to measure the amount of rainfall with an ESP-32 microcontroller which displays results through a Liquid Crystal Display (LCD) and then send it to the registered number and at the same time is been sent to cloud for easy retrieval purpose using the internet which can be retrieved from any location. This system is designed primarily for use in the school meteorological stations, it is also applicable in various weather stations. The primary goal is to create a low-cost intelligent system for storing data obtained by measuring various physical parameters in the atmosphere, such as temperature, humidity, and rainfall. An ESP-32 is used as the technology for storing measured data; it is an advanced and efficient solution for connection to the Internet. The intelligent weather station system is built around the following steps: direct environmental sensing, data measurement and storage, and allowing users to access the results through the cloud. The system is built around a collection of embedded sensors, and a microcontroller serving as the system's core and server, and wireless internet communication protocol. The results were sent to the cloud, where they are displayed in a tabular and graphical format; these results can be retrieved from the cloud into an excel file.

Платформа контроля электромагнитного поля для обеспечения безопасности труда и промышленных объектов

The complex direction of measuring electromagnetic field parameters in Industry 4.0 is the underestimated direction. At the same time, modern technologies are actively testing neural network algorithms and the IoT cluster. Current trends in the development of technology dictate the use of new technologies and materials in the design of sensitive elements of electromagnetic field meters, as well as new intelligent methods for obtaining and processing data in real time. The logical development is the crossing of smart measuring devices and the server part with the required algorithmic modules. The conducted studies and experiment showed an unambiguous possibility of creating an unpacked electromagnetic field sensor. The convergence of the results of modeling real operating conditions in the form of inhomogeneous electromagnetic fields and the results of calculating mathematical block structures confirms the correctness of the models. The purpose of using a platform with structurally improved electromagnetic field sensors is to measure the parameters of the electromagnetic field in real time with the output of targeted quantitative results with a sufficient level of accuracy and predict hazardous situations. The platform is based on the measuring and server parts. Sensors or an assembly of several sensors is the final measurement node capable of functioning without user intervention. The node implements the collection of information about the actual parameters of the electromagnetic field at the object, a lot of nodes form the measuring part of the platform. Processing, storage, and generation of reports (messages) are carried out in the server part of the platform. The connection of the measuring and server parts occurs via wireless Internet communication channels.

Effective Capacity Analysis of NOMA Networks with Short Packets

Low latency and a massive connection have become the requirements of energy internet wireless communication. Effective capacity analysis of non-orthogonal multiple access (NOMA) networks with short packets is of vital importance in energy internet communication planning and design. Low-latency communications are one of the main application scenarios in next-generation wireless networks. This paper focuses on the effective capacity of NOMA networks, where the finite blocklength, delay exponent, and transmission error probability are taken into account. New exact and asymptotic expressions of effective capacities are derived for arbitrarily ordered users with a finite blocklength. Based on the analytical results, the high Signal-to-Noise Ratio slopes of effective capacity in NOMA networks are carefully attained. The numerical results validate that (a) non-orthogonal users are capable of obtaining a larger effective capacity when the blocklength decreases, and that (b), as the value of the error probability and delay exponent increases, the effective capacity of non-orthogonal users worsens.

Securing Communication in IoT Ecosystem Using Cryptographic Algorithms

Internet of Things (IoTs) is defined as an ever-growing network, which comprises of numerous physical objects with a specific IP address along with wireless internet communication, which enables the process of information sharing between two objects. Due to the frequent transfer and exchange of high confidential data between two devices through internet, there arise some susceptible attacks in IoT such as denial of service, eavesdropping attack and so on. A high-level authentication protocol and cryptographic techniques are required to resolve the issue of vulnerable attack and data loss. The current study presents a review of various IoT models and applications. Furthermore, the concerns related to security with respect to data sharing and numerous attacks have been featured in this paper. In order to avoid and minimize these attacks, numerous security measures and cryptographic algorithms have been developed by different authors. The study on several existing protocols has been carried out in this research along with the study on authentication algorithm developed by the authors. The result section contrasts a brief idea about the key requirements for the data security and authentication for the future aspects along with necessity of memory and power utilization. Additionally, some examination has been carried out briefing the future directions in which additionally work would be possible on the development of lightweight cryptography protocols.

Evaluating the LoRaWAN Protocol Using a Permanent Outdoor Testbed

Low-power wide-area network (LPWAN) protocols, such as a long range wide area network (LoRaWAN), are key to ensuring scalable wireless communication for Internet of Things devices. In this paper, an analysis of this protocol through a performance evaluation of a permanent outdoor LoRaWAN tested is presented. To ensure accurate results, tests lasted at least 17 h and required 1000 packets per node. The evaluation focused on the impact that the adaptive data rate (ADR) scheme, payload length, link checks, and acknowledgements had on the packet delivery ratio (PDR) of the testbed. The collected data showed that enabling the ADR scheme reduced the PDR. The ADR scheme had six data rates, which consist of a spreading factor and bandwidth combination, to choose from. Analysis revealed that the scheme primarily assigning either the fastest data rate (SF7BW250) or the slowest (SF12BW125) to nodes, regardless of distance. Furthermore, the scheme’s assignments show the signs of oscillation, with nodes being instructed to abruptly change between SFs. The impact of payload length and link checks on the PDR was not pronounced, but enabling acknowledgements did show significant improvements.

Study on Secrecy Capacity of Wireless Sensor Networks in Internet of Things Based on the Amplify-and-Forward Compressed Sensing Scheme

The wireless sensor networks is a new technology for information acquisition and processing, which includes the techniques of sensor, computer, Internet of Things and network. Due to the fragility of wireless sensor networks, the security issue has become a prevalent concern in the wireless communication for Internet of Things. This paper offers a deep insight to the secrecy capacity of wireless sensor network and a calculable threshold of capacity based on the amplify-and-forward (AF) compressed sensing scheme. Moreover, we provide a feasible algorithm based on augmented Lagrange method for source reconstruction for the legitimate nodes and un-authorized nodes. Furthermore, we also discuss the impact of the numbers of active sensor nodes, relay nodes and eavesdropper nodes to the secrecy capacity. Simulation results demonstrate the correctness of the derived secrecy capacity.

Data Collection and Wireless Communication in Internet of Things (IoT) Using Economic Analysis and Pricing Models: A Survey

This paper provides a state-of-the-art literature review on economic analysis and pricing models for data collection and wireless communication in Internet of Things (IoT). Wireless sensor networks (WSNs) are the main components of IoT which collect data from the environment and transmit the data to the sink nodes. For long service time and low maintenance cost, WSNs require adaptive and robust designs to address many issues, e.g., data collection, topology formation, packet forwarding, resource and power optimization, coverage optimization, efficient task allocation, and security. For these issues, sensors have to make optimal decisions from current capabilities and available strategies to achieve desirable goals. This paper reviews numerous applications of the economic and pricing models, known as intelligent rational decision-making methods, to develop adaptive algorithms and protocols for WSNs. Besides, we survey a variety of pricing strategies in providing incentives for phone users in crowdsensing applications to contribute their sensing data. Furthermore, we consider the use of some pricing models in machine-to-machine (M2M) communication. Finally, we highlight some important open research issues as well as future research directions of applying economic and pricing models to IoT.

Ring-shaped omnidirectional rectangular slotted waveguide antenna with enhanced characteristics

Antennas are becoming crucial in an increasingly growing number of applications namely with the emerging of the wireless internet communications where efficiency, compactness and cost play a decisive role. Nonetheless a major drawback of such solutions is that the aforementioned criteria are hard to simultaneously optimize. In this paper an innovative approach relying on using circularly bent rectangular slotted waveguide antenna as an ultimate alternative is presented that allows drastically enhancing the ratio of performance versus cost and size. Simulation results were carried out at 2.4 GHz frequency and indubitably demonstrated high effectiveness in terms of directivity and high gain given a reduced cost, shape and size.

선박엔진성능분석용 웹기반 장기모니터링시스템 구현

This paper implements a long-term monitoring system (LMS) for ship`s engine performance analysis (SEPA) based on the web, for the purpose of the communication speed and engine maintenance. This system is composed of a simulator, monitoring module with a multi channel A/D converter, monitoring computer, network attached storage (NAS), RS485 serial and wireless internet communication system. The existing products monitor the information transmitted from pressure sensors installed in the upper parts of each of engines in the local or web computer, but have a delay in the communication speed and errors in long-term monitoring due to the large volume of sampling pressure data. To improve these problems, the monitoring computer saves the sampling pressure data received from the pressure sensors in NAS, monitors the long-term sampling data generated by the sectional down sampling method on a local computer, and transmits them to the web for long-term monitoring. Because this method has one tenth of the original sampling data, it will use memory with small capacity, save communication cost, monitor the long-term sampling data for 30 days, and as a result, make a great contribution to engine maintenance.

Noninvasive sEMG-based control for humanoid robot teleoperated navigation

This paper presents an application of noninvasive sEMG-based interface to humanoid robot navigation control between remote places via wireless internet communication. sEMG signals to recognize three wrist movements are measured from the skin of a user’s arm. The wrist movements generate commands to the humanoid robot. The wrist movement directions are assigned to be intuitively comparable with the robot movement directions, therefore a user can control the robot in a natural way. By combining the state automation machine to the sEMG-based interface, possible robot movements are extended. To provide the environmental information of remote places, the images from the camera on the robot’s head are transmitted into the interface PC screen. We conducted experiments in which subjects control a humanoid robot to navigate from a starting position to a destination in a maze. The experimental results demonstrate the feasibility of the proposed interface method by comparing it with the keyboard control.

Remote Image Acquisition and Transmission Framework for Monitoring Plant Growth Based on ARM9

In order to monitor the plant growth in greenhouse, a new method based on GPRS and Internet wireless communication technology was introduced in this paper. It is a system involving S3C2410 of ARM9 kernel as the microprocessor chip, which can be run in Linux operating system and takes the wireless transmission mode of GPRS+Internet as an adoption. The structure of the whole system, hardware design and image acquisition and transmission framework were introduced. A detailed explanation was given about planted method of operating system in the paper.

Editorial for WICON 2010 on “Recent advances in wireless internet”

Networks and Applications (MONET). This special issue is devoted to the topic of the latest research and development on wireless Internet. Wireless Internet is quickly emerging as a reality, thanks to the fast evolution of many wireless access technologies. Convergence of heterogeneous wireless networks and the next generation Internet further brings wireless Internet into a variety of application scenarios which provide mobile users with a wide range of highly demanding services, such as high speed data and real-time multimedia delivery. On the other hand, it is of critical importance to obtain a fundamental understanding of wireless Internet architectures and explore new services and solutions in order to achieve the ultimate goal of wireless Internet access anytime anywhere The aim of this special issue is to present a collection of high-quality research papers that report the latest research advances in wireless Internet communications, networks, systems, services, and applications. The whole special issue includes the extended papers in the 5th Annual International Wireless Internet Conference (WICON 2010), which was held in March 2010 (http://www. wicon.org/2010/). In this special issue, we selected 6 papers. The selected papers covered the following important topics in the field of wireless Internet: cognitive radio, wireless sensor networks, multimedia communications, and vehicular networks. A detailed overview of the selected works is given below. The first paper, Joint Spectrum Allocation and Relay Selection in Cellular Cognitive Radio Networks, presents a cross-layer framework that jointly considers spectrum allocation and relay selection with the objective of maximizing the minimum traffic demand of secondary users in a cognitive radio network cell. This cross-layer design problem is formulated as a Mixed Integer Linear Programming (MILP) and a low complexity heuristic algorithm is proposed to solve the problem. In addition, a spectrum allocation is studied among several cells with the objective of maximizing the overall minimum throughput of all cells while ensuring each individual cell’s minimum throughput requirement. The second paper, Joint Optimization of Power, Packet Forwarding and Reliability in MIMO Wireless Sensor Networks, investigates the reliable packet forwarding in Wireless Sensor Networks (WSNs) with the multiple-input multiple-output (MIMO) and orthogonal space time block codes (OSTBC) techniques. The objective is to propose a cross-layer optimized forwarding scheme to maximize the Successful Transmission Rate (STR) while satisfying the given end-to-end power consumption constraint. The channel coding, power allocation, and route planning are jointly considered to significantly improve the transmission quality in terms of STR. The joint optimization design is Y. Zhang (*) Simula Research Laboratory and University of Oslo, Oslo, Norway e-mail: yanzhang@simula.no

Robust End-to-End Available Bandwidth Estimation forInteractive Satellite networks

This paper presents an efficient and accurate available bandwidth estimation algorithm for satellite links which generally have long propagation delay. Either the method using the rate of returning ACKs or the method using timestamp option is adopted for the bandwidth estimation algorithms to enhance TCP performance in the literature. The method using the rate of returning ACKs, which is the most popular for the available bandwidth estimation for a TCP connection, is known to have the influences from the reverse link (TCP receiver to TCP sender) traffic variation, especially in the asymmetric satellite links. The bandwidth estimation method using packet sending time information from the TCP timestamp option also has the drawback that the influence of the bottleneck link presented in the forward path is not properly considered. To overcome these limits, our algorithm performs in two steps. A forward path delay is calculated at the sender with the receiver sending time for an ACK packet in the first step. And in the second step, the forward path delay is updated more delicately through removing unrelated part from the forward path delay, and is applied for available bandwidth estimation. The simulation results show that our algorithm can avoid the influence of the traffic variation in the return path (e.g., ACK compression, DAMA delay), and estimate the available bandwidth over the forward path more accurately. Satellite networks are becoming the important candidate in information and communication infrastructures because they provide several advantages to the wireless Internet communications. They generally provide wider coverage, higher bandwidth, and relatively faster establishment than other terrestrial wireless networks. Nevertheless, satellite links pose some challenges to the congestion control operation of the TCP (Transmission Control Protocol) (10). Main challenges of the satellite networks to the TCP performance are the long RTT (round-trip time) which is generally around 600msec in the bi-directional networks over the geostationary satellite, and the presence of the high packet loss rate by wireless random error which causes congestion control of the TCP spuriously. To solve the problems while keeping end-to-end semantics of TCP, an accurate bandwidth estimation algorithm is

무선 인터넷기반 실시간 정보 처리를 통한 판넬 공장의 효과적 운용방법 연구

A prototype of MES(Manufacturing Execution System) applied to panel assembly shop is implemented by using PDA(Personal Digital Assistant) and wireless database web server. The system is developed based on the Dot Net framework. The prototype can exchange the manufacturing execution data between production managers in the control room and workers in the factory through wireless internet communication. Manufacturing model of the panel shop is designed by using IDEF0 and UML method to understand the characteristics of the information and the data entities from the PPR-S view. Several issues in the shop were revealed from the manufacturing model analysis. The most typical problem was the lack of information sharing between the managing workers and the assembly workers. The problem prevents the workers and labors from sharing the process information and continuous workpiece flow In interactive way. To increase the information and data flow, a wireless internet based system is implemented and PDAs are linked together to exchange the process planning data and in-process data between the workers. It is anticipated that PDA and the implemented system can enable the process control at each process stages to obtain the well-organized operation.