• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2006.07a
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• pp.632-632
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• 2006

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.615-618
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• 2001

In this paper, a solution of network management system for power plant was introduced. In conventional systems, power installations use serial communication or MODEM for Management. In this case, it has a weak point in distance and speed. To solve these problems, the manage system based on Ethernet was developed. In order to implement, SNMP which is standard NMS of LAN was adapted, agent board and manager program for SNMP were developed.

• Journal of the Semiconductor & Display Technology
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• v.20 no.2
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• pp.131-136
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• 2021

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, a real-time EtherCAT master is implemented on Linux operating systems and its performances are evaluated. To enhance the real-time capability of mainline Linux kernel, Xenomai is applied as a real-time framework and an open source EtherCAT master stack, Simple Open EtherCAT Master (SOEM), is installed on it. Unlike other studies, the real-time performance of the EtherCAT master is evaluated at the output of the network interface card, so that the evaluation results include all possible effects from the EtherCAT master system. The implemented EtherCAT master can send and receive packets up to 20KHz control frequency with low jitter, even in stressed condition.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.12
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• pp.2663-2669
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• 2010

During the past 5 years, domestic VoIP service has grown rapidly absorbing more than 8 million subscribers. More recently, the increase of enterprise or institutional subscribers become more dominant than individual subscribers. Supporting emergency services such as 119 in these scaled up VoIP services is very essential. In current domestic VoIP networks, the VoIP terminal's location information which are provided to the PSAP with the arriving emergency call depends on the information which are entered at the subscription time or updated by the subscribers when the terminal is moved to other place. This manual provision of location information which requires the user's intervention can result in serious failure in saving people in emergency situations, in case that users are negligent in entering the information or users enter the wrong information. In this paper, we propose an enhanced mechanism in which the terminal's location information is automatically offered by the network for emergency services in ethernet-based enterprise VoIP networks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.4
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• pp.822-828
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• 2013

In this paper, a multi-modem for process automation of non-destructive inspection (NDI) which possibly generates various kinds of data is implemented and verified. Here, a variety of data such as control signals, text data, image data generated by inspection devices, sensors, computers are transmitted to the multi-modem via serial, Ethernet, and coaxial cable. We exploit a communication network in which powerlines are used as backbone transmission media. Thus, the implemented multi-modem has various ports and corresponding interfaces for data transmission. As a result of practical experiments, the multi-modem maintains almost constant data rate with little waveform distortion. In addition, the experiments confirm that the modem operates normally under extreme variation of temperature. It is, therefore, considered that the multi-modem can contribute significantly to implement powerline communication (PLC)-based process automation for NDI in which various kinds of data are practically generated.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.1
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• pp.53-59
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• 2011

In this paper, the implementation of a production control system has been studied in order to obtain Realtime Cost Calculation using an exact Machine Factor and Man Factor based on RFID reader data transferred through network. For the study, microprocessor built in the controller of production facilities is used and also RFID reader is built additionally. Control part, card reader used for check the beginning and ending working time of workers, and Machine Factor and Man Factor calculated are transferred to server via PLC transmission port, serial transmission port, or Ethernet transmission port. By using the system, the production cost or the production efficiency is calculated exactly. Therefore it is possible to improve production rate and cost reduction by the use of the proposed production control system.

• Smart Media Journal
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• v.13 no.1
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• pp.52-59
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• 2024

This paper proposes a plan to improve the reception radio environment of the mobile terminal and maintain a constant reception electric field by using small cells in a small closed environment. In order to configure an efficient communication infrastructure for small cells, both ends of wireless transmission and reception of an Ethernet-based wireless video recording system are connected using an L2 switch. The small cell connected to the receiving side L2 switch shares the wireless network section of the wireless video recording system and connects to the transmitting side L2 switch. After that, when it is normally linked to FMS, a management system for small cells, through the Internet network, the output of small cells is checked. In order to verify the results, a proposed network is formed on the elevator inside the building with a poor radio wave environment, and the radio wave environment is measured before and after the small cell application in the section where the elevator operates. As a result, the main parameters of the radio wave environment in all sections of the elevator are improved, as well as a constant receiving electric field strength within the moving elevator.

• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.3
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• pp.132-138
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• 2010

In the present study, the real-time monitoring system is developed based on the wireless sensor network (WSN) and power line communication (PLC) employed in the 3,000-ton-class training ship. The WSN consists of sensor nodes, router, gateway and middleware. The PLC is composed of power lines, modems, Ethernet gateway and phase-coupler. The basic tests show that the ship has rather good environments for the wired and wireless communications. The developed real-time monitoring system is applied to recognize the thermal environments of main-engine room and one cabin in the ship. The main-engine room has lots of heat sources and needs careful monitoring to satisfy safe operation condition or detect any human errors beforehand. The monitoring is performed in two regions near the turbocharger and cascade tank, considered as heat sources. The cabin on the second deck is selected to monitor the thermal environments because it is close to the heat source of main engine. The monitoring results of the cabin show the thermal environment is varied by the human activity. The real-time monitoring for the thermal environment would be useful for the planning of the ventilation strategy based on the traces of the human activity against inconvenient thermal environments as well as the recognizing the temperature itself in each cabin.

• Journal of KIISE:Information Networking
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• v.32 no.5
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• pp.603-614
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• 2005

The wireless LAN environment using Mobile IP is constructed and managed to be connected with Ethernet based wired networks. However, there have been many problems with wireless networks using Mobile IP. Some important facts on network performance have not been considered when introducing wireless LAN by Mobile IP to wired networks. In this paper, we suggest schemes which can solve problems on Handover latency caused by the asymmetrical connectivity of the Access Router at applying the HMIPv6 and on binding updates due to the MN frequent movement. Our proposed schemes can reduce network latency by using the HMIPv6 architecture with a virtual router layer, and reduce communication overhead by interchanging information of the MN movement between routers. Our schemes are expected to assist in constructing a more real and effective wireless LAN environment based on the HMIPv6 and FMIP.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.11
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• pp.635-642
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• 2004

The traditional communication protocols such as TCP/IP are not suitable for PC cluster systems because of their high software processing overhead. To eliminate this overhead, industry leaders have defined the Virtual Interface Architecture (VIA). VIA provides two different data transfer mechanisms, a traditional Send/Receive model and the Remote Direct Memory Access (RDMA) model. RDMA is extremely efficient way to reduce software overhead because it can bypass the OS and use the network interface controller (NIC) directly for communication, also bypass the CPU on the remote host. In this paper, we have implemented VIA-based RDMA mechanism in hardware. Compared to the traditional Send/Receive model, the RDMA mechanism improves latency and bandwidth. Our RDMA mechanism can also communicate without using remote CPU cycles. Our experimental results show a minimum latency of 12.5${\mu}\textrm{s}$ and a maximum bandwidth of 95.5MB/s. As a result, our RDMA mechanism allows PC cluster systems to have a high performance communication method.