Distributed Generation Communications Utilizing a Real-time FPGA-based Channel Simulator in the ISM Frequency Band

Author(s):  
Julian Meng ◽  
Shane Barnes

Deregulation of the power industry, increases in consumer demand of electricity and mandates to reduce greenhouse gases has significantly heightened the interest in distributed generation (DG). Typical DG sources include wind turbines, fuel cells, micro gas/diesel turbines, small hydro generators and photovoltaics. Currently most of these generation sources are optimized for local operation and thus the potential of DG that is both dispatchable and cost-effective has yet to be fully realized. One key technical challenge is the development of low-cost communications for remote telemetry and control of individual DG sources. Along with cost, other key communication system requirements are modularity, range and reliability. This paper presents a distributed generation communication system (DGCS) that is based on a wide area network (WAN) and local area network (LAN) topology and utilizes two variants of low-cost radio modems (RM) to satisfy the desired connectivity between the DG sites and a centralized control center. For the LAN, low-cost RMs operating in the industrial, scientific, and medical (ISM) frequency band offers point-to-multipoint scalability to multiple DG sites within a limited range. Integration of the ISM RMs with a cellular RM provides connectivity to a WAN or Internet thus providing long-range access to DG sites from any facility that has internet-access. Given the LAN scalability requirement, an ISM field programmable gate array (FPGA) channel simulator was developed to assess DGCS performance using channel impairments such as free-space path loss, multipath reflections, additive white Gaussian noise (AWGN), multiple access interference, and narrowband interference. This study provides the evaluation of two commercially available ISM radio modems and recommendations are made based on LAN requirements such as cost and performance given difficult channel conditions.

Author(s):  
Suri Darmiantini ◽  
I Wayan Agus Arimbawa ◽  
Andy Hidayat Jatmika

Technologies that support wireless networks include WLAN (Wireless Local Area Network) and WPAN (Wireless Personal Area Network). One of the most widely used WLAN products today is IEEE 802.11n while the WPAN application is Bluetooth. Using the same frequency band in a coverage area can cause interference. Interference that occurs can be caused due to the use of 2 pieces of the same communication system, as well as different in a region. This study aims to determine how much influence interference has on the decline in the quality of a communication system with parameters measuring bandwidth, jitter, and packet loss. From the results of measurements and analysis shows that network quality is affected due to interference. Where if the network is free from interference around it, the network quality will be better, if the network experiences interference because using the same frequency band in the same coverage area can affect network quality such as reduced bandwidth value, increased jitter, and packet loss as well as channel usage and different channels. And the closer the distance of the access point that uses a different channel in a coverage area will cause the decreasing bandwidth value to increase the value of jitter and packet loss and vice versa. Keywords: interference, wireless, channel, bandwidth, jitter, packet loss.


2021 ◽  
Vol 9 (04) ◽  
pp. 39-46
Author(s):  
Prof. Swarnali Ghosh Dastider ◽  
Luis Rosa

Real-time collaboration of multiple digital models is vital for successful construction projects using Virtual Design and Construction (VDC) or Building Information Modeling (BIM). Real-time collaboration allows users to workshare within a multidisciplinary team to co-author multiple smart digital models for better efficiency. This can be done in two ways, either using a physical server (Local Area Network/LAN server) or cloud-based server (Wide Area Network/WAN server). Such cloud-based servers are A360, C4R, Collaboration for Revit, or BIM360Design collaborate, etc. However, above-mentioned cloud services come at a significant price, making it challenging for academia and small businesses to perform real-time collaboration using BIM/VDC models. To find an affordable alternative, an attempt was made as part of the Virtual Design and Construction (VDC) course offered by the Construction Science and Management Department (CSM). For this case study, a popular and free (Google) cloud server was tested as a WAN server to host four multidisciplinary collaborative VDC central models for five users across five different geographic locations and time zones. The study rendered successful results to establish a real-time collaborative workshare environment; hence, can significantly benefit academia and small business.


2009 ◽  
Vol 10 (2) ◽  
pp. 167-184
Author(s):  
Jaime Sánchez-García ◽  
◽  
Luis A. Villaseñor-González ◽  
Mario E. Vaquera-Flores ◽  
Raúl Aquino-Santos ◽  
...  

2014 ◽  
Vol 960-961 ◽  
pp. 841-844
Author(s):  
Yan Bin Li ◽  
Yun Li ◽  
Wei Guo Li

With the development of the smart grid , information network securityassessment affects the safe operation of the smart grid . In this paper, theimproved credibility theory and analytic hierarchy process , combined withstructural features of the smart grid network , From the wide area network ,access network, enterprise local network , local area network and the CPN-siteand home users to assess the impact of the five aspects of information networksfor smart grid security operation. And make the case for more security strategyto improve the reliability of the smart grid operation , thus providing a basisfor guiding the development and safe use of electricity grid users .


Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 264 ◽  
Author(s):  
José Santa ◽  
Ramon Sanchez-Iborra ◽  
Pablo Rodriguez-Rey ◽  
Luis Bernal-Escobedo ◽  
Antonio Skarmeta

Remote vehicle monitoring is a field that has recently attracted the attention of both academia and industry. With the dawn of the Internet of Things (IoT) paradigm, the possibilities for performing this task have multiplied, due to the emergence of low-cost and multi-purpose monitoring devices and the evolution of wireless transmission technologies. Low Power-Wide Area Network (LPWAN) encompasses a set of IoT communication technologies that are gaining momentum, due to their highly valued features regarding transmission distance and end-device energy consumption. For that reason, in this work we present a vehicular monitoring platform enabled by LPWAN-based technology, namely Long Range Wide Area Network (LoRaWAN). Concretely, we explore the end-to-end architecture considering vehicle data retrieving by using an On-Board Diagnostics II (OBD-II) interface, their compression with a novel IETF compression scheme in order to transmit them over the constrained LoRaWAN link, and information visualization through a data server hosted in the cloud, by means of a web-based dashboard. A key advance of the proposal is the design and development of a UNIX-based network interface for LPWAN communications. The whole system has been tested in a university campus environment, showing its capabilities to remotely track vehicle status in real-time. The conducted performance evaluation also shows high levels of reliability in the transmission link, with packet delivery ratios over 95%. The platform boosts the process of monitoring vehicles, enabling a variety of services such as mechanical failure prediction and detection, fleet management, and traffic monitoring, and is extensible to light vehicles with severe power constraints.


Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1564
Author(s):  
Le Huy Trinh ◽  
Nguyen Vu Truong ◽  
Fabien Ferrero

This work presents the use of a three-element radiating structure for circularly polarized Low-Power Wide Area Network (LP-WAN) communication with space. The proposed structure has a 72 mm × 72 mm × 12 mm compact size with Right-Handed Circular Polarization (RHCP) and a 120∘ wide beamwidth radiation pattern. Printed on low-cost FR4 Epoxy substrate, a feeding network circuit based on Quasi Lumped Quadrature Coupler (QLQC), it achieves a −0.6 dB insertion loss and a very compact size. The final structure has a 69% total efficiency and a 3.14 dBic realized gain.


2009 ◽  
pp. 658-677 ◽  
Author(s):  
Pedro Furtado

Running large data warehouses (DWs) efficiently over low cost platforms places special requirements on the design of system architecture. The idea is to have the DW on a set of low-cost nodes in a nondedicated local area network (LAN). Nodes can run any relational database engine, and the system relies on a partitioning strategy and query processing middle layer. These characteristics are in contrast with typical parallel database systems, which rely on fast dedicated interconnects and hardware, as well as a specialized parallel query optimizer for a specific database engine. This chapter describes the architecture of the nodepartitioned data warehouse (NPDW), designed to run on the low cost environment, focusing on the design for partitioning, efficient parallel join and query transformations. Given the low reliability of the target environment, we also show how replicas are incorporated in the design of a robust NPDW strategy with availability guarantees and how the replicas are used for always-on, always efficient behavior in the presence of periodic load and maintenance tasks.


Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4273
Author(s):  
Jeferson Rodrigues Cotrim ◽  
João Henrique Kleinschmidt

The growth of the Internet of Things (IoT) led to the deployment of many applications that use wireless networks, like smart cities and smart agriculture. Low Power Wide Area Networks (LPWANs) meet many requirements of IoT, such as energy efficiency, low cost, large coverage area, and large-scale deployment. Long Range Wide Area Network (LoRaWAN) networks are one of the most studied and implemented LPWAN technologies, due to the facility to build private networks with an open standard. Typical LoRaWAN networks are single-hop in a star topology, composed of end-devices that transmit data directly to gateways. Recently, several studies proposed multihop LoRaWAN networks, thus forming wireless mesh networks. This article provides a review of the state-of-the-art multihop proposals for LoRaWAN. In addition, we carried out a comparative analysis and classification, considering technical characteristics, intermediate devices function, and network topologies. This paper also discusses open issues and future directions to realize the full potential of multihop networking. We hope to encourage other researchers to work on improving the performance of LoRaWAN mesh networks, with more theoretical and simulation analysis, as well as practical deployments.


Circuit World ◽  
2019 ◽  
Vol 45 (3) ◽  
pp. 141-147 ◽  
Author(s):  
Karthie S. ◽  
Salivahanan S.

Purpose This paper aims to present the design of a novel triangular-shaped wideband microstrip bandpass filter implemented on a low-cost substrate with a notched band for interference rejection. Design/methodology/approach The conventional dual-stub filter is embedded with simple fractal-based triangular-circular geometries through various iterations to reject wireless local area network (WLAN) signals with a notched band at 5.8 GHz. Findings The filter covers a wide frequency band from 3.1 to 8.8 GHz and has a fractional bandwidth of 98 per cent with the lower passband of 57.5 per cent and upper passband of 31.6 per cent separated by a notched band at 5.8 GHz. The proposed wideband prototype bandpass filter is fabricated in FR-4 substrate using PCB technology and the simulation results are validated with measurement results which include insertion loss, return loss and group delay. The fabricated filter has a sharp rejection of 28.3 dB at 5.8 GHz. Measured results show good agreement with simulated responses. The performance of the fractal-based wideband filter is compared with other wideband bandpass filters. Originality/value In the proposed work, a fractal-based wideband bandpass filter with a notched band is reported. The conventional dual-stub filter is deployed with triangular-circular geometry to design a wideband filter with a notched band to suppress interference signals at WLAN frequency. The proposed wideband filter exhibits smaller size and better interference rejection compared to other wideband bandpass filter designs implemented on low-cost substrate reported in the literature. The aforementioned wideband filter finds application in wideband wireless communication systems.


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