• Journal of the Institute of Electronics Engineers of Korea SC
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• v.45 no.2
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• pp.55-60
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• 2008

Packet-switched wavelength division multiplexing (WDM) ring networks have been extensively studied as solutions to the increasing amount of traffic in metropolitan area networks, which is widely expected to be a mix of unicast and multicast traffic. In this paper we study the fairness between unicasting and multicasting in slotted packet-switched WDM ring networks that employ a tunable transmitter and fixed tuned receiver at each node and a posteriori buffer selection. We find that single-step longest queue selection algorithm generally results in unfairness between unicasting and multicasting or a lilted relative priority for multicast vs. unicast traffic. We present the various virtual output queue structures and their performance.

• Proceedings of the KIEE Conference
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• 2001.11c
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• pp.130-133
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• 2001

VoIP(voice over internet protocol) technology is based on IP protocol. The IP protocol can be involved in two types of communication: unicasting and multicasting. Unicasting is the communication between one sender and one receiver. It is one-to-one communication. Multicasting is one-to-many communication. So that, many receivers can get same data from one sender simultaneously. and, the different protocol are proposed for VoIP; H.323, SIP and MGCP. MGCP is perfect server-client protocol, so MGCP is very attractive VoIP protocol to ISP. This paper uses MGCP and offers modified MGCP for conference call. So that, Modified MGCP is compatible to MGCP, and supports conference call using IP-multicast.

• Journal of Korea Multimedia Society
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• v.17 no.2
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• pp.191-199
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• 2014

The unicasting routing technology of VANET is very important for user convenience. Unicasting packets must be forwarded to the appropriate path in order to arrive to the destination. However, there are so many problems because the vehicle nodes have limited information related to the routing decision. In particular, packet delivery failure will be occurred by selecting the path already failed again. We call this problem as 'Failed Path Re-Selection Problem'. In this paper, we propose an enhanced rerouting function of VANET Routing. The proposed rerouting function uses the failed path information when rerouting function executed. For this rerouting function, failed path information will be stored in the packet whenever the routing fail occurred. By the comparison with the performance of legacy VANET routing function, the superiority of the proposed method can be seen.

• Journal of KIISE:Information Networking
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• v.33 no.2
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• pp.165-174
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• 2006

Data dissemination using either flooding or legacy ad-hoc routing protocol is not realistic approach in the wireless sensor networks, which are composed of sensor nodes with very weak computing power, small memory and limited battery. In this paper, we propose the ELF(Energy-efficient Localized Flooding) protocol. The ELF is energy-efficient data dissemination protocol for wireless sensor networks. In the ELF protocol, there are two data delivery phases between fixed source and mobile sink node. The first phase, before the tracking zone, sensing data are forwarded by unicasting. After that, within the tracking zone, sensing data are delivered by localized flooding. Namely, the ELF Properly combines advantages from both unicasting and flooding. According to evaluation results by simulation, the proposed ELF protocol maintains very high data delivery ratio with using a little energy. Also, the property of average delay is better than others. From our research results, the ELF is very effective data dissemination protocol for wireless sensor networks.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.1
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• pp.85-95
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• 2015

Network-on-chip (NoC) has evolved to overcome the issues of traditional bus-based on-chip interconnect. In NoC-reuse as TAM, the test schedulers are constrained with the topological position of cores and test access points, which may negatively affect the test time. This paper presents a scalable hybrid test data transportation scheme that allows to simultaneously test multiple heterogeneous cores of NoC-based SoCs, while reusing NoC as TAM. In the proposed test scheme, single test stimuli set of multiple CUTs is embedded into each flit of the test stimuli packets and those packets are multicast to the targeted CUTs. However, the test response packets of each CUT are unicast towards the tester. To reduce network load, a flit is filled with maximum possible test response sets before unicasting towards the tester. With the aid of Verilog and analytical simulations, the proposed scheme is proved effective and the results are compared with some recent techniques.

• The Transactions of the Korea Information Processing Society
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• v.3 no.4
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• pp.709-719
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• 1996

DHCP(Dynamic Host Configuration Protocol)is a protocol which dynamically allocates an IP address and/or host configuration parameters to a host. But because this protocol uses broadcasting for message exchange, it causes heavy traffic and overload on the network. By avoiding unnecessary broadcasting and using a simple and efficient implementation model, we can reduce such heavy traffic and overload. We have studied on characteristics of the broadcasting the traffic caused by DHCP, and implement the model which can reduce traffic by improving algorithm and unicasting messages.

• Journal of Korea Society of Industrial Information Systems
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• v.8 no.3
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• pp.99-104
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• 2003

Ad-hoc is the wireless network and consists of moving Hosts in environments which don't have a network-based Frame. Because ad-hoc is considered as broadcast network and network which has useful benefits, multicast muting protocols have been studied on ad-hoc network For this work we scrutinized ad-hoc and multicast routing protocols presented in previous works. And we presents a protocol for Ad-hoc network.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.47-53
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• 2012

In this paper, we present an algorithm called redundant logical paths (RLP) for efficient HSR traffic reduction. It creates redundant logical paths between each HSR node and all the other nodes. Eventually, a logical full-meshed network or paths will be established among all HSR node types, except the Quadbox type, which is used only for interconnection. The logical full-meshed network will be used instead of using the standard HSR protocol that depends on the concepts of the duplication and forwarding of the received frame until it reaches the destination node. The RLP algorithm results in significantly less frame traffic because there is no random forwarding as in the standard HSR protocol. For the sample network in this paper simulation results showed a 61.5-80% reduction in network frame traffic compared to the standard HSR. Our algorithm will avoid latency issues in the network and even network congestion, thus improving network efficiency.

• Proceedings of the Korea Multimedia Society Conference
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• 2012.05a
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• pp.193-194
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• 2012

현재 자연재해 증가와 응급 상황 발생이 빈번해짐에 따라 정부에서 소방법을 강화하였다. 따라서 대부분의 빌딩에서는 응급 상황이나 자연 재해 발생이 발생할 경우, 신속한 대피를 위한 안내 방송을 할 수 있는 전관 방송 시스템 설비를 반드시 갖추어야 한다. 이에 본 연구에서는 빌딩에 설비되어 있는 각종 다양한 센서들로부터 센싱된 정보를 네트워크를 통해 전달 받아 이들을 실시간으로 분석하여 빌딩 상황에 맞는 안내 방송과 응급 상황시 대피를 위한 안내 방송뿐만 아니라 빌딩에 있는 각 호수별로 ID를 부여하고, 이를 통해 방송이 필요한 장소에만 개별 방송을 할 수 있는 디지털 전관 방송 시스템을 개발하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2008.06d
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• pp.406-411
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• 2008

무선 MAC 을 위한 802.11은 유니캐스팅 통신을 할 때 ACK를 이용하여 자체적인 신뢰성을 부여한다. 그러나 오류율이 낮거나 패킷 크기가 작은 환경에서 TCP와 같이 상위 계층의 신뢰성 보장 기능이 있는 경우 MAC 계층에서 모든 패킷에 대해 ACK를 이용하는 것은 오버헤드가 될 수 있다. 본 논문에서는 ACK 응답을 하지 않는 멀티캐스팅을 통해 유니캐스팅 통신 을 구현하는 802.11 ACK-less 유니캐스팅 기법을 제안하고 기존의 ACK 기반의 802.11 유니캐스팅과 통신 성능 및 에너지 측면에서 비교 실험하였다. 실험결과 에러율이 낮고, 패킷의 크기가 작고, LAN 통신 환경에서 처리율과 에너지 측면에서 우수한 성능을 보인다. 반면 무선 통신 환경이 열악한 경우에 에너지 효율은 유지하더라도 처리율은 뒤떨어지는 현상이 나타났다. 이를 보완하기 위해 선택적 ACK-less 유니캐스트 기법을 제안한다.