Wireless Smart Utility Network Research Articles

Analysis and Evaluation of Channel-Hopping-Based MAC in Industrial IoT Environment

Owing to the development of the Internet-of-Things (IoT) paradigm, channel hopping is the most widely used method for solving multipath fading problem caused by various structures in industrial environments or by external interference of communication devices using the same frequency band. To meet these demands, IPv6 over the time slotted channel hopping (TSCH) mode of IEEE 802.15.4e (6TiSCH) has emerged as the standard for low power lossy networks in industrial IoT environments. TSCH supports slot-based channel hopping with the IEEE 802.15.4e standard and ensures reliable connection from external interference through strong time synchronization. Wireless Smart Utility Network (Wi- SUN), which constructs a Field Area Network (FAN), proposes non-slotted channel hopping and specifies only minimum constraints. However, there is limited existing research on these networks. Therefore, in this study, we analyze and evaluate the performance of channel-hopping-based medium access control (MAC) in an industrial environment. Simulation results in various environments show that non-competitive MAC provides reliable and efficient transmission.

Analysis of AMI Communication Methods in Various Field Environments

In order to construct an efficient on-site communication network for an advanced metering infrastructure (AMI) in Korea, the high-speed power line communication (HS PLC), wireless smart utility network (Wi-SUN), and ZigBee modems are currently being used. In this paper, we first quantitatively analyze the communication performances of HS PLC, Wi-SUN, and ZigBee modems for AMI through both experimental testbeds and practical environment sites. For practical AMI sites, we selected 18 sites with 48 measurement points and classified the sites into five areas, and conducted measurements of signal and noise power spectra on the sites. We then derived linear regression models for received powers according to areas. Through the constructed models, we can efficiently choose an appropriate communication method and plan a methodology for building an AMI network depending on the area type. Furthermore, using the constructed regression models, we provided graphical simulation tools of received powers for both PLC and wireless communication methods based on a distribution information map.

A Wireless Sensor Network for Growth Environment Measurement and Multi-Band Optical Sensing to Diagnose Tree Vigor

We have tried to develop the guidance system for farmers to cultivate using various phenological indices. As the sensing part of this system, we deployed a new Wireless Sensor Network (WSN). This system uses the 920 MHz radio wave based on the Wireless Smart Utility Network that enables long-range wireless communication. In addition, the data acquired by the WSN were standardized for the advanced web service interoperability. By using these standardized data, we can create a web service that offers various kinds of phenological indices as secondary information to the farmers in the field. We have also established the field management system using thermal image, fluorescent and X-ray fluorescent methods, which enable the nondestructive, chemical-free, simple, and rapid measurement of fruits or trees. We can get the information about the transpiration of plants through a thermal image. The fluorescence sensor gives us information, such as nitrate balance index (NBI), that shows the nitrate balance inside the leaf, chlorophyll content, flavonol content and anthocyanin content. These methods allow one to quickly check the health of trees and find ways to improve the tree vigor of weak ones. Furthermore, the fluorescent x-ray sensor has the possibility to quantify the loss of minerals necessary for fruit growth.

IEEE 802.15.4/4e準拠無線スマートユーティリティネットワーク用低消費電力MACプロトコルF-RITの実装・評価

Smart metering systems with Wireless Smart Utility Network (Wi-SUN) have been introducing in gas and water infrastructures for optimal management of energy and resources. These wireless systems require low-power consumption to operate long period, e.g., 10 years by battery operation. One of the solutions is development of Media Access Control (MAC) protocol for low-power operation. The Feathery Receiver Initiated Transmission (F-RIT) protocol is one of the implementable low-power consumption MAC protocol complied with IEEE 802.15.4g global standard for the MAC layer of the Wi-SUN systems. In this paper, the feasibility and effectiveness of the F-RIT protocol are experimentally investigated in terms of communication link establishment success rate performance and power consumption performance by implementing the F-RIT protocol on commercial Wi-SUN modules equipped with IEEE 802.15.4g complied RF module.

Implementation of a Low-Cost Energy and Environment Monitoring System Based on a Hybrid Wireless Sensor Network

A low-cost hybrid wireless sensor network (WSN) that utilizes the 917 MHz band Wireless Smart Utility Network (Wi-SUN) and a 447 MHz band narrow bandwidth communication network is implemented for electric metering and room temperature, humidity, and CO2 gas measurements. A mesh network connection that is commonly utilized for the Internet of Things (IoT) is used for the Wi-SUN under the Contiki OS, and a star connection is used for the narrow bandwidth network. Both a duty-cycling receiver algorithm and a digitally controlled temperature-compensated crystal oscillator algorithm for frequency reference are implemented at the physical layer of the receiver to accomplish low-power and low-cost wireless sensor node design. A two-level temperature-compensation approach, in which first a fixed third-order curve and then a sample-based first-order curve are applied, is proposed using a conventional AT-cut quartz crystal resonator. The developed WSN is installed in a home and provides reliable data collection with low construction complexity and power consumption.

地域におけるWi-SUNとスマートフォンの融合利活用による徘徊高齢者捜索支援システム

地域におけるWi-SUNとスマートフォンの融合利活用による徘徊高齢者捜索支援システム