• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.3
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• pp.1052-1070
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• 2016

Wireless Body Area Networks (WBANs) have received a lot of attention as a promising technology for medical and healthcare applications. A WBAN should guarantee energy efficiency, data reliability, and low data latency because it uses tiny sensors that have limited energy and deals with medical data that needs to be timely and correctly transferred. To satisfy this requirement, many multi-radio multi-channel MAC protocols have been proposed, but these cannot be implemented on current off-the-shelf sensor nodes because they do not support multi-radio transceivers. Thus, recently single-radio multi-channel MAC protocols have been proposed; however, these methods are energy inefficient due to data duplication. This paper proposes a TDMA-based single-radio, multi-channel MAC protocol that uses the Unbalanced Star+Mesh topology to satisfy the requirements of WBANs. Our analytical analysis together experiments using real sensor nodes show that the proposed protocol outperforms existing methods in terms of energy efficiency, reliability, and low data latency.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.535-540
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• 2003

In this Paper, a LON based distributed control system for HVAC is described. We developed multi-protocol converter based on SoC, Neuron Chip, embedded Linux. It utilizes the network environment and therefore requires an appropriate operating system for handling protocols and an advanced development environment. The open source licensing, reliability, and broad hardware support are key reasons for use of embedded Linux in embedded industry. The multi-prootocol converter integrates LonWorks devices to a client with Java applet. The system consists of three-tier architecture, such as clients, multi-protocol converter, and LonWorks devices. The experiment result show that multi-protocol converter using embedded Linux is a flexible and effective way to build a Web-based monitoring and control system.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.1-10
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• 1995

Since there is currently no commercial protocol simulator for CDMA mobile communication system, we need to develop a General-Purposed Protocol Test Simulator (G-PTS). This paper is concerned with the design and implementation of this G-PTS contains the multi-scenario generating functions, multi-tasking kernel and multiple interface functions. Thus it can be utilized in the test category using multiple base-stations such as soft-handoff, 3-way handoff and mulit-party call features. G-PTS is verified using the model of CDMA soft handoff scenario and the result shows its reliable operations.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2006.06a
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• pp.303-310
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• 2006

The sorting algorithms have been developed to take advantage of distributed computers. But the speedup of parallel sorting algorithms decrease rapidly with increased number of processors due to parallel processing overhead such as context switching time and inter-processor communication cost. In this paper, we propose a parallel sorting method which provides linear speedup of an optimal serial algorithm for a system with a large number of processors. This algorithm may even provide superlinear speedup for a practical system. The algorithm takes advantage of an interconnection network properties and its protocol.

• Journal of electromagnetic engineering and science
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• v.12 no.2
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• pp.142-147
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• 2012

In this paper, we propose a novel protocol called Cooperative Multi-hop transmission using Incremental Relaying (CMIR). We evaluate the performance of the CMIR protocol by deriving expressions for the average end-to-end outage probability and the average number of transmissions. Monte Carlo simulations are presented to verify the accuracy of the theoretical analyses.

• The Journal of the Korea Contents Association
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• v.9 no.8
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• pp.73-83
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• 2009

TCP(Transmission Control Protocol) is currently used connection-oriented protocol as a typical transport layer protocol in the Internet. However, it has deficiency not be able to communicate with other TCP entities when any link included in the path is down because of single-homing on single path. SCTP(Stream Control Transmission Protocol) suggested as the new transport layer protocol supports multi-homing feature, which provides several paths between source and destination. It can communicate with other SCTP entities using alternate path even when any link on the primary path is down. This paper aims to measure and analyze the multi-homing effect of SCTP over TCP in case of link-down using NS-2 simulator. We classify SCTP into $SCTP_{single-homing}$ and $SCTP_{multi-homing}$ because SCTP with single-homing can also be used like TCP. We measured throughput and bandwidth utilization varying link-down duration, bandwidth, and RTT(round trip time), Simulation results show that throughput of $SCTP_{multi-homing}$ is more than that of TCP by 18 % on average. It is also shown that $SCTP_{multi-homing}$ on varying RTT and bandwidth increases the throughput of TCP by 'l7% and 9% on average, respectively in the link-down environment. In above cases, more or less difference between $SCTP_{single-homing}$ and TCP on throughput and bandwidth utilization was found To summarize, multi-homing effect of SCTP over TCP on throughput is about 18 % on average in the link-down environment This experimental result can be used as the benchmark in order to estimate the multi-homing effect of SCTP over TCP when the link-down happens in the real Internet.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.10
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• pp.110-118
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• 2007

In multi-hop wireless network, multi-channel makes it possible to enhance network performance because it reduces channel interferences md contentions. Recently several schemes have been proposed in the literatures to use multi-channel. Especially, MCR(Multi channel routing protocol), which utilize hybrid interface assignment, is a prominent routing protocol. MCR uses simple way to change channel but efficiently reduce channel interferences. In this paper, we propose a load-aware channel selection algorithm called LCS that enhances the channel switching algerian used in MCR protocol. In LCS, channel of a node is assigned based on collected information about queue length of neighbors. Moreover this paper evaluates the performance of in by using simulation test and testbed demonstration. Test results show that the MCR with LCS outperforms the naive MCR.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.326-334
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• 2016

In this paper for developing and implementing the realtime HD level video streaming transmitter which is operated on the multi-platform in all network and client environment compared to the exist video live streaming transmitter. We design the realtime HD level video streaming transmitter supporting the multi-platform using the TMS320DM386 video processor of T.I company and then porting the Linux kernel 2.6.29 and implementing the RTSP(Real Time Streaming Protocol)/RTP(Real Time Transport Protocol), HLS(Http Live Streaming), RTMP(Real Time Messaging Protocol) that can support the multi-platform of video stream protocol of the received equipments (smart phone, tablet PC, notebook etc.). For proving the performance of developed video streaming transmitter, we make the testing environment for testing the performance of streaming transmitter using the notebook, iPad, android Phone, and then analysis the received video in the client displayer. In this paper, we suggest the developed the Realtime HD(High Definition) level Video Streaming transmitter performance data values higher than the exist products.

• The Journal of Korea Robotics Society
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• v.4 no.1
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• pp.1-9
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• 2009

Radio Frequency Identification (RFID) is an automatic identification method. Information such as identification, logistics history, and specification of products are written and stored into the memory of RFID tags (that is, transponders), and retrieved through RF communication between RFID reader device and RFID tags. RFID systems have been applied to many fields of transportation, industry, logistics, environment, etc in order to improve business efficiency and reduce maintenance cost as well. Recently, some research results are announced in which RFID devices are combined with other sensors for mobile robot localization. In this paper, design of multi-protocol baseband for RFID reader device is proposed, and the baseband modem is implemented into SoC (System On a Chip). The baseband modem SoC for multi-protocol RFID reader is composed of several IP (Intellectual Property) blocks such as multi-protocol blocks, CPU, UART(Universal Asynchronous Receiver and Transmitter), memory, etc. As a result, the SoC implemented with FPGA(Field Programmable Gate Array) is applied to real product. It is shown that the size of RFID Reader module designed with the FPGA becomes smaller, and the SoC chip price for the same function becomes cheap. In addition, operation performance could be the same or better than that of the product with no SoC applied.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.16 no.2
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• pp.13-24
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• 2006

We consider a privacy-preserving cooperative computation protocol evaluating a beneficial function of all participants' secret inputs, such that each party finally holds a share of the function output. We propose a practical privacy-preserving cooperative computation protocol for solving the linear system of equations problem md the linear least-squares problem. Solutions to these problems are widely used in many areas such as banking, manufacturing, and telecommunications. Our multi-party protocol is an efficiently extended version of the previous two-party model.