• Journal of KIISE:Information Networking
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• v.30 no.5
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• pp.573-580
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• 2003

Increasing user demand for the more bandwidths in wireless communications has motivated a new challenge to utilize the benefits of wireless ATM technology This paper focuses on how to provide IP services to a mobile user over wireless ATM networks. By enhancing the NHRP standard, several shortcomings are improved that are resulted from the naive combinations of Mobile IP over ATM and IP over wireless ATM. This paper presents a mobile location management algorithm that is referred to as the Mobile NHRP scheme. The mobile tracking procedure and the mobile locating procedure are explicitly defined in the proposed scheme. On the locating procedure, the source station may obtain the current location of the destination from NHSs(Next Hop Servers). Therefore the optimized connection can be setup directly. The total costs per move and per setup over ATM/IP overlaid networks are estimated.

• Journal of Communications and Networks
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• v.2 no.1
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• pp.35-45
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• 2000

this paper presents the concept of "mobile ATM', a proposal for third-generation (3G) mobile communication network infrastructure capable of supporting flexible evolution of radio technologies from today's cellular and data services towards future wireless multimedia services. Mobile ATM provides generic mobility management and QoS-based transport capabilities suitable for integration of multiple radio access technologies including cellular voice. wireless data, and future broadband wireless services. The architecture of a mobile ATM network is outlined in terms of the newly-defined "W-UNI" interface at the radio link and "M-UNI"and "M-UNI" interface which supports unified access for WATM and non-ATM mobile terminals through corresponding interworking functions (IWF) is explained. leading to an understanding of how different radio access technologies are supported by the same ATM-based core network infrastructure. Generic mechanisms for handoff and location management within the core mobile network are discussed. and related protocol extensions over the "W-UNI" and "M-UNI/NNI"interfaces are proposed. the issue of "crossover switch (COS)" selection in mobile ATM is considered, and a unified handoff signaling syntax which supports flexibility in COS selection is described. Typical signaling sequences for call connection and handoff using the proposed protocols are outlined. Experimental results form a proof-of-concept mobile ATM network prototype are presented in conclusion.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10c
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• pp.811-813
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• 2001

본 논문에서는 기존의 IP 망에서 호스트의 이동성을 지원하기 위한 Mobile IP 개념을 ATM 망에 적용할 경우, Mobile IP망에서 Home Agent와 Foreign Agent 사이에 존재하는 Mobile-IP 터널링 구간을 기존의 LAN 기반의 IP 터널링 구간과 ATM 망에서의 단거리 터널링(short-cut tunneling) 구간으로 구분하여 관리하는 방안을 제안하였다. Short-cut 터널링을 설정하기 위하여 NHRP를 이용하였으며 Shot-cut 터널링을 이용함으로써 HA 와 FA 사이에 데이터 전달 지연을 기존의 IP 터널링에서의 데이터 전달 지연보다 줄일 수 있음을 시뮬레이션을 통해 확인하였다.

• Annual Conference of KIPS
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• 2001.04b
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• pp.681-684
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• 2001

본 논문에서는 기존의 IP 망에서 호스트의 이동성을 지원하기 위한 Mobile IP 개념을 ATM 망에 적용할 경우, Mobile IP 망에서 HA(Home Agent)와 FA(Foreign Agent) 사이에 존재하는 Mobile-IP 터널링(tunneling) 구간을 기존의 LAN 기반의 IP 터널링 구간과 ATM 망에서의 단거리 터널링(short-cut tunneling) 구간으로 구분하여 관리하는 방안을 제안하였다. 특히 ATM 망에서의 short-cut 터널링을 구성하기 위하여 기존의 NHRP 프로토콜을 이용함으로써 대량의 데이터 전송 시 종단간 전송 지연을 줄일 수 있는 장점이 있다. 본 논문에서는 송신노드, 이동노드, HA 및 FA 가 이질적인 두 망에 존재하는 경우 적절한 Mobile-IP 터널링 구간을 이룰 수 있음을 보인다.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.189-198
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• 2001

In recent years, the predominant part in telecommunications is mobile communications. The next generation network is extending today's voice-only mobile networks to multi-service networks. ATM Network is possible to carry such multi-media traffic and it will be expect to use wireless ATM for the future mobile access network. One of manly important aspects for the performance of wireless ATM is the Medium Access Control (MAC) protocol. The MAC protocol must be able to satisfyingly handle the different ATM services (CBR, VBR, ABR and UBR) with their radically different performance requirements. Additionally, the MAC protocol must be able to cope with the complex radio environment where fading, multi-path propagation interference and burst-errors further complicate the situation. In this paper, a dynamic slot allocation algorithm in wireless ATM is proposed for an efficient channel sharing/media access at the MAC layer. We use equivalent capacity in the allocation of slots for VBR traffic which is variable along the time. It is simple and effective slot allocation method for VBR service. In particular, we consider the slot allocation of a session consisted of several connections for requirement of multimedia traffic. Simulation shows that the cell loss ratio is reduced by re-allocation of extra slots in Mobile Terminal (MT).

• Proceedings of the Korean Information Science Society Conference
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• 1998.10a
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• pp.208-210
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• 1998

본 논문에서는 무선 ATM에서 이동 IP 서비스를 제공하기위해 "Mobile NHRP"라는 새로운 방안을 제안한다. IP망과 WATM망을 연동하고자할 때 사용하는NHRP기법과 Mobile PNNI기법을 혼용할 때 발생하는 비효율성을 지적하고 그 대안을 제시한다. 제안된 Mobile NHRP에서 이동 NHC와 연결설정을 이루기 위해 홈LIS를 거치지 않고 직접적으로 NHC와 연결하도록 하는 ATM망에서 효율적으로 빠르게 이동 단말로의 IP연결성이 이루어지도록한다. 이루어지도록한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.9A
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• pp.2230-2239
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• 1998

Recently, mobility support of connectionless mobile ATM data service has been mainly studied in wireless ATM communication network. this paper shows the network model for the mobility support of connectionless data service in ATM network, and proposes the methods to minimize COIP (care of IP address) acquisition processing time for MH(mobile host)migration. Th echaracteristics of proposed methods, COIP acquisition probability and IP data communication sequence of proposed model, are discussed in this paper.

• Journal of Korea Multimedia Society
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• v.6 no.5
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• pp.831-841
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• 2003

In wireless ATM network, Mobile terminals must offer function and QoS such as terminal of wire ATM network. The fast notification of BS (Base Station) scheduler about ATM cells arriving in mobile terminals is a critical item of the ATM-based centrally controlled MAC protocol. But, Collision is arisen at process that several mobile terminals require data transmission by contention method through uplink and because of re-transmission by collision, throughput of decrease and transmission delay increases. In this paper, We propose the MAC protocol that decide optimized request mini-slot's number considering number of request terminal predicted as statistical and its posterior throughput. According to simulation result, could know that proposed protocol shows high performance delay and throughput.

• Proceedings of the IEEK Conference
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• 2000.07a
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• pp.229-232
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• 2000

AAL2 has been adopted for bandwidth-efficient trans-mission of low bit tate traffic over ATM networks in ITUT and ATM Forum. Since ATM/AAL2 is expected to be used as a switching technology in third-generation mobile access networks and mobile data traffic is expected to increase rapidly in near future, there must be a need for efficient scheduling scheme satisfying the QoS requirement of ow bit rate voice as well as the one of high bit rate data. In this paper, we propose a new class-scheduling scheme to improve data packet loss probability, while Qos of voice traffic is guaranteed, when data traffic is multiplexed together with mobile voice traffic into a single ATM VCC. The proposed scheme can efficiently support data traffic by assigning a time threshold value to voice traffic. Through simulation study, we show that the proposed scheme does not only achieve better efficiency for providing both mobile voice and data services than HOL class-scheduling scheme and normal FIFO scheme, but also guarantees mean voice packet delay under a certain criteria.

• Electronics and Telecommunications Trends
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• v.13 no.2 s.50
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• pp.10-28
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• 1998

무선 ATM에서는 위치관리 기법으로는 PNNI 라우팅 프로토콜의 확장과 기존의 셀룰러 전화망의 위치 등록기 개념에 근거한 방식들이 제안되고 있는데 크게 Mobile PNNI 방식과 Location Register(LR) 방식으로 나누어진다. Mobile PNNI 방식은 기존의 PNNI 라우팅 프로토콜을 기반으로 하여 단말기의 이동성을 제공할 수 있도록 수정 확장한 위치 관리 기법이다. Mobile PNNI 방식에서는 단말기가 이동할 경우에 영역 변수(scope parameter) S에 의해 제한된 범위 내에서 교환국 간에 reachability information이 갱신되며, 이러한 정보를 이용하는 PNNI 라우팅 프로토콜을 기반으로 하여 위치 추적과 호 설정이 동시에 수행된다. LR 방식은 Mobile PNNI 방식과는 달리 발신호가 발생하게 되면, 계층적인 구조의 위치 등록기들의 추적을 통해 상대편 이동 단말기가 접속된 교환국의 위치 정보를 알아낸 다음, 호 설정 과정을 수행하게 된다. 본 연구에서는 무선 ATM에서의 여러 가지 위치관리 요구사항을 살펴보고, 위에서 언급한 두 가지 방식에 대하여 자세히 소개하고, 이들을 비교 분석한다.