• Title, Summary, Keyword: IWF

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Implementation of IWF function based on MG(Media Gateway) System (MG(Media Gateway) System에 기반한 IWF 기능 구현)

  • Kang, Deok-Ki;Lee, Jong-Chan
    • 한국정보통신설비학회:학술대회논문집
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    • pp.491-494
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    • 2008
  • 과거 CDMA 시스템에서 이동단말과 PSTN 및 PSDN간의 통신이 가능하게 하기 위해서는 망간의 정합기능을 수행하는 연동장치(IWF Inter-Working Function)가 필요로 되는데, 이때 이동단말과 BSC/MSC간의 무선 데이터를 IWF로 HDLC 프레임 형태로 구동하고 반대로 IWF로부터 수신된 데이터 프레임을 이동 단말측으로 전달하기 위하여 HDLC frame driver의 역할이 필요하다. 또한 교환기와 IWF간의 데이터 통신은 Frame-relay 프로토콜을 이용하며 정합기능을 수행해 주어야 한다. 본 논문에서 구현된 기능은 과거 CDMA 의 MSC 내에 구현된 본 기능이 HDLC 정합, Frame-Relay 정합, IPC, Datapath 등의 기능들로 구분되어 분리되어 있는 구조를 통합하여 하나의 기능 Board로 통합하였고 이러한 기능을 MG(Media Gateway) System에 기반하여 구현하여 적용하였다.

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Effects of Added Yam Powders on the Quality Characteristics of Yeast Leavened Pan Breads Made from Imported Wheat flour and Korean Wheat Flour (마(Dioscorea) 첨가가 우리밀과 수입밀을 이용한 식빵 품질특성에 미치는 효과)

  • 이선영;김창순
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.1
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    • pp.56-63
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    • 2001
  • This study investigated the quality characteristics of yeast breads with addition of hot air-dried yam powder (HDYP) and freeze-dried yam powder (FDYP), using several physical and sensory examinations. Breads were made of imported wheat flour (IWF) or Korean wheat flour (KWF). HDPY and FDYP were added to the bread formula at three levels of 3, 5, and 7%. The addition of yam powders required an increase of water absorption. As the addition of HDYP/FDYP increased, IWF dough stickiness increased and thus handling property became inferior to the control. Especially, handling property of KWF bread dough containing FDYP was most poor among the dough samples. With HDYP/FDYP, final volumes of bread made from IWF were similar to the control when 3~5% HDYPs were added whereas loaf volumes decreased significantly as the amount of added FDYP increased, indicating volume depressing effect. In bread scoring, texture scores increased when yam powders were added that hardness, chewiness, cohesiveness and guminess of KWF bread increased as the amounts of yam powders increased. The "L" value of IWF bread crumb decreased with the addition of yam powders. From sensory evaluation using acceptability scores, the results gave us that appearance, grain, texture, flavor, taste and overall acceptability of KWF bread could be more improved with the addition of yam powders than those of IWF bread.IWF bread.

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Performance Analysis of Interworking Protocol for Efficient Mobile Data Service (효율적인 이동 데이타 서비스를 위한 연동 프로토콜의 성능 분석)

  • 박성수;송영재;조동호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.7
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    • pp.1744-1754
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    • 1998
  • In this paper, the data service protocol which could support data service more efficiently between mobile host and fixed host in wire network is investigated. Wireless link has high bit error rate compared with wire link. Therefore, TCP performance for the data service is degraded in wire and wireless interworking environment. Thus, to reduce performance degradation. Interworking module withsimple protocol processing function is proposed. This, interworking module analyzes the hearder information of TCP fram. If received TCP freame is a duplicated frame, TCP frame is discared. Also, if interworking moudule receives retransmission request frame is a duplicated frame, TCP freme is discarded. Also, if interworking module receives retansmission request frame, interworking module performs retransmission procedure. According to simulation results, the proposed IWF shows better performance than traditional IWF in view of delay and throughput in the wire and wireless interworking environments.

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An On/Off Power Control for OFDM Transmission Scheme in a Cochannel Interference Environment (동일 채널 간섭 환경에서 OFDM 전송 방식을 위한 온/오프 송신 전력 제어)

  • Park, Jin-Kyu;Lim, Chang-Heon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.10A
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    • pp.1042-1049
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    • 2007
  • Frequency reuse in a cellular wireless communication environment gives rise to a phenomenon of cochannel interference. This paper introduces a power control strategy for OFDM based communication systems operating in such an environment. Among the existing power control schemes, IWF(iterative waterfilling) is known to exhibit relatively good performance. However, it requires feedback of power level and bit allocation information for each subcarrier from a receiver to its associated transmitter, which can lead to a considerable overhead, especially for the case of employing large number of subcarriers. Motivated by this, we present a simplified power control scheme with reduced overhead feedback, which allocates some nonzero identical power to the subcarriers of which channel conditions are above a certain threshold and zero power to the other ones. Computer simulations show that the proposed strategy produces a good approximation to the performance of the IWF in terms of the transmission power level while it requires less overhead feedback.

An On/Off Power Control for OFDM Transmission Scheme in a Cochannel Interference Environment (동일 채널 간섭 환경에서 OFDM 전송 방식을 위한 온/오프 송신 전력 제어)

  • Park, Jin-Kyu;Lim, Chang-Heon;Kim, Jin-Yul
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.11A
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    • pp.1182-1189
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    • 2007
  • Frequency reuse in a cellular wireless communication environment gives rise to a phenomenon of cochannel interference. This paper introduces a power control strategy for OFDM based communication systems operating in such an environment. Among the existing power control schemes, IWF(iterative waterfilling) is known to exhibit relatively good performance. However, it requires feedback of power level and bit allocation information for each subcarrier from a receiver to its associated transmitter, which can lead to a considerable overhead, especially for the case of employing large number of subcarriers. Motivated by this, we present a simplified power control scheme with reduced overhead feedback, which allocates some nonzero identical power to the subcarriers of which channel conditions are above a certain threshold and zero power to the other ones. Computer simulations show that the proposed strategy produces a good approximation to the performance of the IWF in terms of the transmission power level while it requires less overhead feedback.

Design and implementation of the interworking function for call processing control between B-ISDN and N-ISDN (B-ISDN과 N-ISDN간의 호처리 제어 연동기능부 설계 및 구현)

  • 유상신;김중철;김영궁;박정식;장경훈;김덕진
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.10
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    • pp.48-60
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    • 1996
  • This paper focuses on the necessities of interworking and dervation of the requirements of interworking system for interworking between 64 Kbps based N-ISDN (narrowband ISDN) and B-ISDN(broadband ISDN). Furthermore, the design and the implementation of IWF (interworking function) are presentd. We analyze two ISDN signalling systems, and propose the architecture of interworking system. And then we make the baisc call procedure model between N-ISDN and B-ISDN, and verify the dynamic behaviors through the reachability tree of petri net. IWF is designed and implemented for transforming the differences between the two signalling systems. The operational confirmity of th eimplemented program was confirmed by the local test method. The performance of IWF was evaluated throguh the simulation language SLAM-II. As the result of evaluation shows, we confirm that the processing delay is maintained within 3 ms under the utilization 0.9.

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The behavior of a shared buffer ATM switch in a LAN environment (LAN 환경제어에서의 공유버퍼 ATM 스위치의 동작 특성)

  • 전병천;도미선;김영선
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.33A no.4
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    • pp.68-77
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    • 1996
  • In this paper, we investigate the effect of a LAN traffic on the performance of a shared buffer ATM switch andIWF (interworking function )on a LAN environment through simulations. Firstly, the delay and the buffer occupancy of the switch and IWF are mesured according to the proportion of the LAN traffic to the traffic generated by gernoulli process. Secondly, we investigate the behavior of the switch in the case that LAN traffic is concentrated to a connectionless server, and the effect of LAN traffic shaping at IWF on the delay and the buffer occupancy of the switch.

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Trusted Non-3GPP Access Interworking in 3GPP 5G System (3GPP 5G 시스템에서 Trusted Non-3GPP 액세스 연동 기술)

  • Kang, Yoohwa;Kim, Changki
    • Journal of Digital Contents Society
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    • v.19 no.4
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    • pp.639-647
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    • 2018
  • A common core network is the one of main architectural principles in 3GPP 5G System which has common interfaces with different multiple accesses. 3GPP 5G System Phase 1 (Release 15) supports Untrusted Non-3GPP access as well as 3GPP access with common interfaces. Non-3GPP Interworking Function (N3IWF) has been defined to interface with a UE and a core network for supporting Untrusted Non-3GPP access in 3GPP Release 15. However, interworking with Trusted Non-3GPP access is under study to be completed in 3GPP 5G System Phase 2 (Release 16). Therefore, this paper proposes a Trusted Non-3GPP access network architecture and related signaling procedures, and then the implementation based on the proposal shows how to interwork between Trusted Non-3GPP access and the 5G core network. In our proposal, N3IWF can interwork with either Untrusted or Trusted Non-3GPP access without any architectural modification or addition of 3GPP 5G system Phase 1.

Design for OAM Translator in Heterogeneous Networks (이종망간 OAM 상호 연동을 위한 변환기 설계)

  • 양진홍;강수진;김철수
    • Proceedings of the Korean Information Science Society Conference
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    • pp.715-717
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    • 2004
  • 인터넷의 폭발적인 성장으로 인하여 MAN(Metropolitan Area Network)은 기존 음성 트래픽 전송 중심의 SONET/SDH(Synchronous Optical NETwork/Synchronous Digital Hierarchy) 환경에서 데이터 트래픽을 수용 할 수 있는 MSPP(MultiService Provisioning Platform) 환경으로 변해가고 있다. 이러한 네트워크 환경에서 이종 망간의 스위칭 역할을 수행하는 NG-SDH장비는 각 망간의 OAM을 제공하기 위해 OAM(Operation/Administration/Maintenance)신호에 대한 IWF(InterWorking Function) 기능을 필요로 하게 된다. 본 논문은 이종 망간 OAM 기능 제공을 위한 IWF에 대해 분석, 정의하고 이를 기반으로 NG-SDH 장비 블록 내에서 이종망간 OAM 기능을 제공할 OAM 변환기를 설계하였다.

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A Power Control for OFDM Transmission Scheme in a Cochannel Interference Environment (동일 채널 간섭 환경에서 OFDM 전송 방식을 위한 송신 전력 제어)

  • Park, Jin-Kyu;Lim, Chang-Heon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.3A
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    • pp.271-280
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    • 2007
  • This paper presents a power control scheme for OFDM based wireless communication systems in a multicell environment with co-channel interference which enables each system to achieve its target level of transmission bit rate. Generally, the optimal or near optimal power control scheme for multicarrier systems is Down to control the power level of each subcarrier in accordance with the associated channel status, which may be found in WF(waterfilling) and WF(iterative waterfilling) schemes. However, this requires the channel state information associated with every subchannel to be fed back from the receiver to its transmitter for successful power control. If the wireless channel exhibits relatively fast fading or the number of subcarriers is large, this may result in a considerable overhead. Here, in order to alleviate this problem, we propose a power control strategy for an OFDM systems maintaining the same power level over all the subcarriers. Also we prove its convergence, compare its complexity with that of the existing IWF algorithm, and examine its convergence characteristic through computer simulations.