scholarly journals Correction: Janssen, T., et al. LoRa 2.4 GHz Communication Link and Range. Sensors 2020, 20, 4366

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6428
Author(s):  
Thomas Janssen ◽  
Noori BniLam ◽  
Michiel Aernouts ◽  
Rafael Berkvens ◽  
Maarten Weyn
Keyword(s):  
Communication Link ◽  
Range Sensors

The authors wish to make the following corrections to this paper [...]

Analysis of Inter-Satellite Optical Wireless Communication System

2017 ◽  
Vol 7 (10) ◽  
pp. 10
Author(s):  
Rajbir Singh
Keyword(s):  
Wireless Communication ◽  
Optical Networks ◽  
Data Transmission ◽  
High Speed ◽  
Open Space ◽  
Communication Link ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
High Speed Data ◽  
Speed Data Transmission

Optical networks are bandwidth efficient networks are used for long haul communication providing seamless data transfer. For high speed data transmission in open space between different satellites, Inter-satellite Optical wireless communication (IsOWC) is widely used .In this paper we have evaluated the performance of IsOWC communication link for high speed data transmission .The performance of the system is evaluated on the basis of qualitative parameters such as Q-factor and BER using optisystem simulator.

Conservation and Preservation of Nature Reserves, Monuments andSpecial Architectural or Historic Interest in Nigeria: Towards Promotion of Sustainable Cultural Tourism

2015 ◽  
Vol 3 (2) ◽  
pp. 201-218
Author(s):  
Francis Chuma Osefoh
Keyword(s):  
Cultural Tourism ◽  
Nature Reserves ◽  
Communication Link ◽  
Built Environments ◽  
Tourist Attraction ◽  
The Past ◽  
Personal Experiences ◽  
Historical Heritage ◽  
Developed Nations

Some of the renowned world tourism countries have special peculiarities in character in terms of their nature reserves and built environments; that made them stand out for their attractions and visits. These qualities range from conservation and preservation of nature reserves, built environments- epoch architectural supports over the years; historical heritage; political; religious; socio-economic; cultural; and  high technology that enhance culture. The virtues of multi- ethnic groups and multi- cultural nature gave Nigeria a rich cultural heritage, and she is blessed with natural wonders, unique wildlife, and a very favorable climate. More often than not less attention and importance are placed over the nature reserves and built environments to the detriment of tourism in lieu of other sectors. Summarily the country lacks the culture of conservation and preservation of her abundant resources to promote cultural tourism. Case study strategy was applied in the research tours with reports of personal experiences, documentaries and analyses of sites visited in Europe and Nigeria were highlighted with references to their attributes in terms of structures and features that made up the sites as relate to culture and attraction.The task in keeping rural, city landscapes and nature reserves alive stands out as the secret of communication link from the past to present and the future; which tourism developed nations reap as benefits for tourist attraction.

Experiment Protocol Boosters Over Inmarsat-ISDN Communication Link

2003 ◽  
Author(s):  
Brian B. Luu ◽  
Christopher M. Sadler
Keyword(s):  
Communication Link

scholarly journals A Cost-Effective Decentralized Control for AC-Stacked Photovoltaic Inverters

Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2262 ◽  
Author(s):  
Hua Han ◽  
Chao Luo ◽  
Xiaochao Hou ◽  
Mei Su ◽  
Wenbin Yuan ◽  
...  
Keyword(s):  
Decentralized Control ◽  
Cost Effective ◽  
Current Control ◽  
Control Mode ◽  
Communication Link ◽  
Grid Voltage ◽  
Point Tracking ◽  
Pv Inverter ◽  
Communication Links ◽  
Voltage Phase

For an AC-stacked photovoltaic (PV) inverter system with N cascaded inverters, existing control methods require at least N communication links to acquire the grid synchronization signal. In this paper, a novel decentralized control is proposed. For N inverters, only one inverter nearest the point of common coupling (PCC) needs a communication link to acquire the grid voltage phase and all other N − 1 inverters use only local measured information to achieved fully decentralized local control. Specifically, one inverter with a communication link utilizes the grid voltage phase and adopts current control mode to achieve a required power factor (PF). All other inverters need only local information without communication links and adopt voltage control mode to achieve maximum power point tracking (MPPT) and self-synchronization with grid voltage. Compared with existing methods, the communication link and complexity is greatly reduced, thus improved reliability and reduced communication costs are achieved. The effectiveness of the proposed control is verified by simulation tests.

A 2 × 20 Gbps hybrid MDM-OFDM–based high-altitude platform-to-satellite FSO transmission system

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Vel Murugan Gomathy ◽  
T. V. Paramasivam Sundararajan ◽  
C. Sengodan Boopathi ◽  
Pandiyan Venkatesh Kumar ◽  
Krishnamoorthy Vinoth Kumar ◽  
...  
Keyword(s):  
High Altitude ◽  
Orthogonal Frequency Division Multiplexing ◽  
High Speed ◽  
Satellite Communication ◽  
Input Power ◽  
Transmission System ◽  
Communication Link ◽  
Space Optics ◽  
High Altitude Platform ◽  
Mode Division Multiplexing

AbstractIn the present study, the application of free space optics (FSO) transmission system to realize a long-reach high-altitude platform (HAP)-to-satellite communication link has been exploited. High-speed information transmission without interference is accomplished using orthogonal frequency division multiplexing (OFDM). Further, the information capacity of the proposed system is increased by employing mode division multiplexing (MDM). We have investigated the proposed MDM-OFDM-HAP-to-satellite FSO transmission system performance over varying FSO range, diameter of the receiver, pointing errors, and input power. Also, an improved transmission performance of the proposed system using a square root module is reported.

scholarly journals Experimental Evaluation of a LoRa Wildlife Monitoring Network in a Forest Vegetation Area

2021 ◽  
Vol 13 (5) ◽  
pp. 115
Author(s):  
Mike Oluwatayo Ojo ◽  
Davide Adami ◽  
Stefano Giordano
Keyword(s):  
Monitoring Network ◽  
Forest Vegetation ◽  
Delivery Ratio ◽  
Communication Link ◽  
Wildlife Monitoring ◽  
Design Development ◽  
Sustainable Solutions ◽  
Iot Applications ◽  
Dense Forest ◽  
Smart Agriculture

Smart agriculture and wildlife monitoring are one of the recent trends of Internet of Things (IoT) applications, which are evolving in providing sustainable solutions from producers. This article details the design, development and assessment of a wildlife monitoring application for IoT animal repelling devices that is able to cover large areas, thanks to the low power wide area networks (LPWAN), which bridge the gap between cellular technologies and short range wireless technologies. LoRa, the global de-facto LPWAN, continues to attract attention given its open specification and ready availability of off-the-shelf hardware, with claims of several kilometers of range in harsh challenging environments. At first, this article presents a survey of the LPWAN for smart agriculture applications. We proceed to evaluate the performance of LoRa transmission technology operating in the 433 MHz and 868 MHz bands, aimed at wildlife monitoring in a forest vegetation area. To characterize the communication link, we mainly use the signal-to-noise ratio (SNR), received signal strength indicator (RSSI) and packet delivery ratio (PDR). Findings from this study show that achievable performance can greatly vary between the 433 MHz and 868 MHz bands, and prompt caution is required when taking numbers at face value, as this can have implications for IoT applications. In addition, our results show that the link reaches up to 860 m in the highly dense forest vegetation environment, while in the not so dense forest vegetation environment, it reaches up to 2050 m.

Impact of Pointing Error on the BER Performance of an OFDM Optical Wireless Communication Link over Turbulent Condition

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Bobby Barua ◽  
S. P. Majumder
Keyword(s):  
Noise Analysis ◽  
Data Rate ◽  
Channel Noise ◽  
Communication Link ◽  
Optical Wireless ◽  
Power Penalty ◽  
Major Power ◽  
Pointing Error ◽  
Turbulent Condition ◽  
Ber Performance

AbstractAn analytical approach is developed in this paper to evaluate the bit error rate (BER) performance of an optical wireless (OW) communication system with multiplexing of the RF orthogonal frequency division (OFDM) over turbulent condition taking into account the effect of pointing error. The received signal is detected through direct detection receiver followed by RF synchronous demodulation including the effect of OW channel and different form of noises such as receiver thermal noise, background channel noise and photo detector shot noise. Analysis is developed for an OFDM system over the OW channel, taking into account the effect of pointing error between the transmitter and the receiver in turbulent condition and the analysis reveals that the OFDM OW system is less affected by pointing error with deference to the major power penalty at BER performance. For instance, power penalty at BER 10−9 is found to be 3 dB for 256 OFDM subcarriers with 9 millidegree displacement angle at a data rate of 10 Gbps under turbulent condition. It is found that the system is more influenced by the atmospheric turbulence at a higher data rate.

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