Jae-Jo Lee

Medium access control for power line communications: an overview of the IEEE 1901 and ITU-T G.hn standards

Power lines are becoming increasingly popular for high-speed communications, while at the same time reliable communications over them poses several unique challenges. Recently, two standardization bodies, the Institute of Electrical and Electronics Engineers (IEEE) and the International Telecommunication Union (ITU), addressed in their IEEE 1901 and ITU-T G.hn standards, respectively, both the medium access control and the physical layer specifications of power line communications. In this article, we provide an overview of these standards from the media access control technology perspective, and the similarities and dissimilarities between the IEEE 1901 and ITU-T G.hn standards are discussed, as well as potential performance issues. We use a top-down approach to analyze the features and technologies of the standards.

Power line communication network trial and management in Korea

Power line communication (PLC) has become an important network access technology to conveniently and effectively provide various useful services such as remote meter reading, broadband Internet access, and home networking services. As the deployment and use of PLC networks increase, it is essential that we need to be able to configure, monitor, and control the PLC network resources. In this paper, we present an overview of PLC network technology and describe a trial PLC network and its deployment in Korea. We then present the design and implementation of a network management system for PLC networks. The experience on the deployment and management of the trial PLC network is also presented.

A SINR-Based MAC Protocol for Wireless Ad Hoc Networks

In this paper, we propose a power control MAC protocol that improves the spatial reuse of wireless channels and the energy efficiency for the wireless nodes. The main idea is to adopt IEEE 802.11 Power Saving Mechanism (PSM) with the appropriate power control scheme for the wireless ad hoc networks. All control messages containing the transmission power information are transmitted at the maximum transmission power in the Announcement Traffic Indication Message (ATIM) window while the data packets are sent at the minimum required transmission power during the data window. Based on the sensing power or the transmission power information of the control messages, a neighbor node checks whether it can transmit simultaneously. Simulation results show the advantages of the proposed protocol in terms of the aggregate throughput, average delay, energy efficiency and fairness index.

A Lightweight Algorithm for Probability-Based Spectrum Decision Scheme in Multiple Channels Cognitive Radio Networks

Compare with the sensing-based spectrum decision scheme, the probability-based spectrum decision scheme has been shown to yield a shorter queuing delay time in Cognitive Radio (CR) system that consists of many Primary Users (PUs) and Secondary Users (SUs). However, the former scheme had cumbersome algorithms and slowly converging speed. In this paper, by introducing Lagrange function, we propose a lightweight algorithm with the computational effort O(N) to define the optimal distribution probability vector. Numerical results demonstrate a high degree of accuracy for the derived expressions.

BER Performance of QPSK-Transmitted Signal for Power Line Communication under Nakagami-like Background Noise

Power line communication (PLC) technology is used in various areas of a smart grid. The extensive use of PLC technology has proved its key role in smart grids throughout the world. Despite PLCs advantages, it suffers from a difficulty in modeling and analysis of its power line channel. Many researchers have experimented and proposed channel models for their own defined environments; as a result, a unified model for the power line has not been presented. To overcome this problem partially, we used a Nakagami-m distribution like background noise and analyzed the performance of the binary transmission system in our previous work. In this paper, we compare the analytical and simulated BER (bit error rate) performances of QPSK (quadrature phase shift keying) transmission system with Gray encoding. We verify that the analyzed and simulated performances are well matched for different values of m.

A Systematic Approach to Analyzing Multipath Parameters From PLC Channel Response

The reliable analysis of the power-line communication (PLC) channels is necessary to model, design, and implement a well-matched PLC transceiver. However, a typical power-line channel has not yet been properly described since it is difficult to analyze the time- and space-varying characteristics. Consequently, it is still very important to measure, analyze, and model the power-line channel well. In this paper, focusing on the analysis of the channel response, we suggest a novel systematic approach to analyzing the multipath parameters. The proposed approach is convenient in that we can systematically find the multipath parameters like time delays and attenuation factors including magnitudes and phases from the measured complex impulse response. The simulation and experimental results show that the proposed approach is valid and appropriate for a typical power-line channel.

A study on the implementation of inductive coupler with rogowski coil for BPLC

In this paper, using a rogowski coil with a non-saturation characteristic to high current, a novel broadband inductive coupler for broadband power line communication (BPLC) has been first proposed and implemented. The frequency behavior of the rogowski coil has been analyzed in order to obtain a broadband frequency response for BPLC. Based on analyzed results, a non-saturated inductive coupler with broadband frequency response has been implemented. The variation of insertion loss of the implemented inductive coupler with the rogowski coil and the conventional inductive coupler with magnetic material according to magnitude of current has been measured, and then the performance of the implemented inductive coupler is verified to compare the measured results.

Characteristic Parameter Analysis on Medium Voltage Power Distribution Line for BPLC

Characteristic parameters for 22.9 kV medium voltage (MV) over-head power distribution lines are studied to broadband power line communication (BPLC) high data rate service that allocated frequency range of 2 MHz to 40 MHz. Characteristic impedance of MV power line is obtained between 470Omega and 530Omega. It depends on the cable cross-section area. Also it should be noted that when frequency is lower than 20 MHz, the characteristic impedance of MV power line, with the effect of ground conductivity, becomes slightly higher than when it is assumed the ground is perfect conductor.

Analysis of impedance characteristics of MV power distribution line for BPLC

In this paper, an impedance characteristics of a Medium Voltage(MV) power distribution line in the frequency range of 1 MHz to 40 MHz for Broadband Power Line Communication (BPLC) has been analyzed and verified experimentally. In order to analyze the impedance characteristics of MV BPLC system, the 2-port equivalent model has been used. Especially, the input impedance values of MV power distribution lines have been obtained between 200 Omega and 300 Omega, which are about a half of the characteristic impedance values of MV power distribution lines. Then the analyzed input impedance has been verified by measuring reflection coefficients at the signal input terminal of a MV power distribution line through the vector network analyzer in the given MV test field. From the experiment, the measured results are very similar to the analyzed results.

Adaptive algorithms to enhance routing and security for wireless PAN mesh networks

Wireless PAN Mesh Network (WMN) is currently going to be standardized and enhanced to take full advantages of the flexible and heterogeneous networks Although the standard (802.15.5) is under-construction, WMNs are expected to become popular as they have the ability to connect all kinds of current networks So far, there is no applied architecture which is efficient enough to completely solve routing and security problems in WMN To assist IEEE P805.15 in routing and security aspects, in this paper, we propose an adaptive algorithm for detecting bogus nodes when they attempt to intrude into the network by attacking routing protocol In addition, a procedure to find the most optimal path between two nodes is presented along with adaptive pre-conditions for WMNs We also show that our algorithm is robust according to the mobility of the nodes and it is easy to implement in currently proposed architectures It can work with many kinds of wireless networks as well as can reduce computational costs.