• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.237-241
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• 2008

Femtocells are cellular access points that connect to a mobile operator's network using residential DSL or cable broadband connections. They have been developed to work with a range of different cellular standards including CDMA, GSM and UMTS. Like legacy base station, the frequency accuracy and phase alignment is necessary for ensuring the quality of service (QoS) for applications such as voice, real-time video, wireless hand-off, and data over a converged access medium at the femtocell. But, the GPS has some problem to be used at the femtocell, because it is difficult to set-up, depends on the satellite condition, and very expensive. So, some techniques are discussed to alternate with the legacy GPS system. NTP, PTP, Synchronous Ethernet use the ethernet to synchronize distributed clocks in packet networks. AGPS support reliable position information than the legacy GPS in poor signal conditions. But, These method also have some problems. So, hybrid timing method like A-GPS+PTP and TV+GPS was developed to make up the weak point of GPS. This paper introduces the each method and compare each other and y propose much better solution for timing synchronization at the Femtocell

• Journal of Korea Multimedia Society
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• v.11 no.7
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• pp.1007-1015
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• 2008

In order to provide real-time data from sensors and instruments at manufacturing processes on web, we proposed a communication service model based on XML(eXtensible Markup Language). HTML(Hyper Text Markup Language) is inadequate for describing real-time data from manufacturing plants while it is suitable for display of non-real-time multimedia data on web. For applying XML-based web service of process data in Intranet environment, real-time performance of communication services was evaluated to provide the system design criteria. XML schema for the data presentation was proposed and its communication performance was evaluated by simulation in terms of transmission delay due to increased message length and processing delay for transformation of raw data into defined format. For transformation of raw data into XML format, we proposed two structures: one is the scheme where transformation is done at an SCC(Supervisory Control Computer) after receiving real-time data from instruments. the other is the scheme where transformation is carried out at instruments before the data are transmitted to the SCC. Performances of two structures were evaluated on a testbed under various conditions such as six packet sizes and offered loads of 20%, 50% and 80%, respectively. Test results show that proposed schemes are applicable to the systems in Ethernet 100BaseT network if total message traffic is less than 7 Mbps.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1495-1500
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• 2004

The interface link for railway signaling systems is generally point-to-point communication scheme, but there have been several efforts to apply the network technology to these interface link in overseas country. However general Ethernet scheme has several drawbacks, so this scheme cannot meet the very high reliability, safety and real-time properties. To overcome these drawbacks, there have been studies reduction and modeling of data collision probability for this ethernet at the industrial and academic world. Therefore, in this paper we analyzed describe a interface trend using network technology between railway signaling equipments and will describe a major technology and framework of a network for railway signaling system.

• Journal of Institute of Control, Robotics and Systems
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• v.14 no.5
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• pp.467-472
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• 2008

In this paper, we design, implement and apply network physical layer to 100 BaseFx optical cable interface module based on industrial ethernet protocol which is physical layer of EtherCAT that has ensure its open standard ethernet compatibility which having been provided with real time of control in network of intelligent service robot, can be process numerous data to sensor and motor control system. Through BLDC motor control performance tests, we try to propose suitability as internal network of intelligent service robot and automation system.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.152-156
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• 2000

Many industrial equipments use RS-232C interface. But Ethernet using CSMA/CD was widly spread recently. This interface is not compatible with RS-232C and requires PC based system. So In this Paper, We decribe a Internet control and monitoring system that control and watch plants without PC. We developed IP controller consisted of microprocessor and NIC and monitoring system using VC++ and SQL database. The protocol used this system is UDP/IP because it is applicable for real time system.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.7
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• pp.887-892
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• 2007

In this paper, we design, implement and apply network physical layer to 100 BaseFx optical cable interface module based on industrial ethernet protocol EtherCAT that has ensure its open standard ethernet compatibility which haying been provided with real time of control in network of intelligent service robot, can process numerous data to sensor and motor control system. Through various tests, we try to propose suitability as internal network of intelligent service robot.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.1
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• pp.43-49
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• 2019

Recently, the importance of industrial fieldbus has been highlighted since the emergence of Industry 4.0. In particular, the Ethernet-based fieldbus protocol is actively used in automation systems. This paper proposes a safety fence system based on EtherCAT, a type of Ethernet-based fieldbus, to measure external loads. In order to measure the external loads, a force sensor was connected to an EtherCAT slave that transmits the sensor data to an EtherCAT master in real-time. The master ultimately controls the angle of the safety fence when it detects danger based on the given data. In the future, more effiecient safety fence system will be developed by using a HMI system to communicate with the EtherCAT master to manage safety and by employing multiple sensors to increase the accuracy of the fence system.

• Journal of Korean Port Research
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• v.5 no.2
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• pp.39-63
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• 1991

A PC-based ship maneuvering simulator was developed which was configured in a high performance IBM PC compatible i486 and i286 computer with a TMS 340 graphic signal processor and 10 MBPS Ethernet Cards. A real-time ship maneuvering simulation program was developed which includes computer generated imagery (CGI) for bird's eye view type and perspective view type. The simulator H/W was designed and manufactured and S/W for interface of various navigation equipments was made Especially, programs for output, analysis, and assessment of simulations results were developed. Communications between PC's are made by using Ethernet bus type LAN system. Simulations could be performed under various environments (current, wind, wave etc.) using data base of harbors and ships. This system can be used for various purposes such as crew's training, harbor and waterway design, and assessment of ship maneuverability in harbor.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.39-48
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• 2016

One of the major trends of automotive networking architecture is the introduction of automotive Ethernet. Ethernet is already used in single automotive applications (e.g. to connect high-data-rate sources as video cameras), it is expected that the ongoing standardization at IEEE (IEEE802.3bw - 100BASE-T1, respectively IEEE P802.3bp - 1000BASE-T1) will lead to a much broader adoption in future. Those applications will not be limited to simple point-to-point connections, but may affect Electric/Electronic(EE) Architectures as a whole. It is agreed that IP based traffic via Ethernet could be secured by application of well-established IP security protocols (e.g., IPSec, TLS) combined with additional components like, e.g., automotive firewall or IDS. In the case of safety and real-time related applications on resource constraint devices, the IP based communication is not the favorite option to be used with complicated and performance demanding TLS or IPSec. Those applications will be foreseeable incorporate Layer-2 based communication protocols as, e.g., currently standardized at IEEE[13]. The present paper reflects the state-of-the-art communication concepts with respect to security and identifies architectural challenges and potential solutions for future Ethernet Switch-based EE-Architectures. It also gives an overview and provide insights into the ongoing security relevant standardization activities concerning automotive Ethernet. Furthermore, the properties of non-automotive Ethernet security mechanisms as, e.g., IEEE 802.1AE aka. MACsec or 802.1X Port-based Network Access Control, will be evaluated and the applicability for automotive applications will be assessed.

• Journal of Internet Computing and Services
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• v.22 no.5
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• pp.17-26
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• 2021

This paper is about a physical layer frame security technique using OFB-style encryption/decryption with AES algorithms on Gigabit Ethernet network. We propose a data security technique at the physical layer that performs OFB-style encryption/decryption with AES algorithm with strong security strength when sending and receiving data over Gigabit Ethernet network. Generally, when operating Gigabit Ethernet network, there is no security features, but data security is required, additional devices that apply this technique can be installed to perform security functions. In the case of data transmission over Gigabit Ethernet network, the Ethernet frames conform to IEEE 802.3 specification, which includes several fields to ensure proper reception of data at the receiving node in addition to the data field. When encrypting, only the data field should be encrypted and transmitted in real time. In this paper, we show that only the data field of the IEEE802.3 frame is encrypted and transmitted on the sending node, and only the data field is decrypted to show the plain text on the receiving node, which shows that the encryption/decryption is carried out correctly. Therefore, additional installation of devices that apply this technique can increase the reliability of the system when security for data is required in Ethernet network operating without security features.