• The Magazine of the IEIE
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• v.33 no.12 s.271
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• pp.69-81
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• 2006

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.15 no.5
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• pp.85-90
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• 2015

Work environments within the firm with a concept of mobile office is growing divided into two sections. It's Wi-Fi FMC(Fixed Mobile Convergence) field Which are implemented in a telephone service available from existing fixed-line service in the center of the smart phones and the EMS(Enterprise Mobility Service) field to make people will be able to handle PC the center of the information system within an enterprise using a smart phone instead of terminal facility connects to a system in the workplace and external. This paper developed FMC controller to allow execution IMS(IP Multi-Media Subsystem) services to complement the issues of the FMC corporation, telephony service associated. The controller includes FMC automatic enrollment services, voice quality enhancement of the mobile phone, anywhere within the firm on his mobile phone calls can provide mobility and is also implemented FMC LCR function that use status information from mobile soft-phone within the IP-PBX.

• Journal of Internet Computing and Services
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• v.9 no.2
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• pp.35-42
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• 2008

Mobile IP is a solution to support mobile nodes, however, it does not handle NEtwork MObility (NEMO). The NEMO Basic Support (NBS) protocol ensures session continuity for all the nodes in the mobile network. Since the protocol is based on Mobile IP, it inherits the same fundamental problem such as tunnel convergence, when supporting the multicast for NEMO. In this paper, we propose the multicast route optimization scheme for NEMO environment. We assume that the Mobile Router (MR) has a multicast function and the Nested Mobile Router Information (NeMRI) table. The NeMRI is used to record o list of the CoAs of all the MRs located below it. And it covers whether MRs desire multicast services. Any Route Optimization (RO) scheme can be employed here for pinball routing. Therefore, we achieve optimal routes for multicasting based on the given architecture. We also propose cost analytic models to evaluate the performance of our scheme. We observe significantly better multicast cost in NEMO compared with other techniques such as Bi-directional Tunneling, Remote Subscription, and Mobile Multicast based on the NBS protocol.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.2
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• pp.57-64
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• 2011

The NGN (Next Generation Network) means the kernel infrastructure technology to provide information and communication services which are able to be used at present and future when a ubiquitous computing era has been realized. In other words, NGN can be the frame providing the same information and communication services anytime and anywhere regardless of wire and wireless. The broadband convergence network that has been built in the public institution has established a broadband multimedia communication network supporting voice telephone, task net, internet network, video conference network, voice over IP (VoIP) network and etc. It is possible for a requested bandwidth and services to be served, only if a broadband convergence network provide the interoperability between the various classes which include a transport network layer, network control layer, service control layer and other layers. In this paper, we analyzed the interoperability issues of the present broadband convergence network and propose a guideline for the future one.

• International journal of advanced smart convergence
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• v.6 no.2
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• pp.1-8
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• 2017

Recently, the development of the information communication industry has made many changes in the industrial acoustic industry. Especially, it has a great influence on the change of system and equipment of acoustic system. Analog equipment is changing to digital equipment, and integrated control equipment makes it easier to operate and manage the sound system. However, the integrated control system currently on the market is only controllable for some devices. In this paper, we propose a new AoIP - based system configuration method, which enables the operation status monitoring, unmanned operation and self - diagnosis of equipment. As a result of the study, it is confirmed that the proposed system can be operated, monitored, and self - diagnosed at remote sites. It is expected that an AoIP- based sound system will be the industry standard in the future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.4
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• pp.1006-1025
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• 2012

Improving the quality of service in IP networks is a major challenge for real-time voice communications. In particular, packet arrival-delay variation, so-called "jitter," is one of the main factors that degrade the quality of voice in mobile devices with the voice-over Internet protocol (VoIP). To resolve this issue, a receiver-based enhanced timing recovery algorithm combined with active jitter estimation is proposed. The proposed algorithm copes with the effect of transmission jitter by expanding or compressing each packet according to the predicted network delay and variations. Additionally, the active network jitter estimation incorporates rapid detection of delay spikes and reacts to changes in network conditions. Extensive simulations have shown that the proposed algorithm delivers high voice quality by pursuing an optimal trade-off between average buffering delay and packet loss rate.

• Information and Communications Magazine
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• v.24 no.3
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• pp.5-14
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• 2007

NGN (Next Generation Network)은 현재 IP기반의 네트워크 기능을 효과적으로 수용하면서 기존의 IP 및 전기통신 서비스뿐만 아니라 앞으로 예상되는 IP 기반 서비스를 효율적으로 제공하기 위한 표준 네트워크 프레임워크라고 여겨진다. 이를 표준화하기 위하여 ITU-T SG13 및 NGN-GSI (NGN-Global Standards Initiative)에서 ITU-T의 관련 연구 그룹들이 참여하여 요구되는 네트워크 및 서비스의 표준화를 매우 적극적으로 추진하고 있다. 우리나라의 BcN도 ITU-T의 NGN 표준화 결과 및 국내 상황을 고려하여 표준모델을 설정하고, 이를 기반으로 IP 기반의 광대 역 고품질 네트워크 프레임워크 틀을 만들어 가고 있다. 본고는 이러한 국내외 상황을 고려한 BcN/NGN 표준화 동향 및 ITU-T NGN의 프레임워크 및 구조, NGN의 서비스 기능 구조, NGN의 자원 관리 및 제어, 유무선 통합 (Fixed Mobile Convergence) 및 NGN Security 구조 등의 표준화 동향에 대하여 기술한다.

• Proceedings of the Korean Information Science Society Conference
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• 2002.10e
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• pp.76-78
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• 2002

Multicasting over mobile IP network becomes more important with the increasing needs of supporting multimedia services in mobile network. The IETF has suggested two approaches which are remote subscription and bidirectional tunneling for supporting mobility management in multicasting over mobile IP. But these protocols have problems - the frequent reconstruction of multicast delivery tree, packet less during handoff, convergence problem, and so on. In this paper, we propose to use preconfiguration of multicast delivery tree when mobile host enters the foreign network. It will decrease the frequency of multicast delivery tree reconstruction, and reduce the packet loss during handoff, Also the multicast delivery tree maintained by Keep Alive messages makes the signaling overload of networks diminished.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.10
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• pp.34-40
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• 2014

With the economical data service delivery, the packet transport network (PTN) technologies have emerged as an important player in the next-generation transport networks. As the PTN continues to make such considerable progress, it is being challenged by network providers who need rapid and reliable recovery capabilities to guarantee the availability of their services. This paper introduces several fault detection mechanisms for a client signal failure in packet transport networks and proposes a reliable transmission method of IP flows from routers using the combination of Ethernet services. Based on the first fault detection methods, client signal fault is detected within tens or hundreds of milliseconds. It enables the client network devices to perform their own recovery processes within one second. The second mechanism enables failed Ethernet services to be bypassed via other Ethernet services over disjoint paths, so as to contribute on reducing packet loss of IP traffic.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.13 no.6
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• pp.17-22
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• 2013

Heterogeneous radios are used in disaster management agencies for a variety of reasons though the radio must have the same radio frequency and protocol for voice communication. For this reason, the variety of heterogeneous radio voice connection methods have been studied but these are simple analog voice line cross connection or partial networked based on digitalization. In this paper, we suggest the method of voice packet transmission method based on All-IP per radio through IP network using SIP/RTP for scalability and openness and developed a prototype of the proposed method was verified.