• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.677-678
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• 2012

The B3G network architecture by the connection of access network is divided into two forms:tightly-coupled networks and loosely-coupled networks. In this paper, we consider the tightly-coupled networks in the internetworking architecture of mobile network.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.679-680
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• 2012

The B3G network architecture by the connection of access network is divided into two forms:tightly-coupled networks and loosely-coupled networks. In this paper, we consider the loosely-coupled networks in the internetworking architecture of mobile network.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.2 no.3
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• pp.48-60
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• 2003

With the rapid successful deployment of WLANs worldwide in numerous hotspots for high data rate, wireless access for data services has created the need to integrate the Cellular Networks with WLAN Networks. The integrated wireless environment will provide the end user a much better service experience along with a single subscription and a single bill. In this paper we focus on inter-working approaches, which combine WLANs and Cellular Networks into an integrated wireless environment capable of ubiquitous access to data services and very high data rates in hotspots areas. We first list the key requirements which are currently being standardized within the 30PP for integration with WLANs networks. We discuss two inter-working architectures namely loosely coupled and tightly coupled This paper will detail the loosely coupled inter-working approach while briefly discussing the tightly coupled inter-working. Finally, we will conclude that the loosely coupled approach is evolutionary and less intrusive than the tightly coupled approach.

• Journal of Internet Computing and Services
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• v.6 no.5
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• pp.123-132
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• 2005

By complementary integration of WLAN and UMTS, a Beyond third Generation(B3G) mobile network can be constructed to establish the fastest global roaming environments, There are 2 types of B3G networks: loosely-coupled and tightly-coupled, A tightly-coupled network demands lots of investment and considerable amount of time to construct. On the other hand a loosely-coupled network is more scalable and easier to implement than a tightly-coupled one, But it has critical drawbacks of packet loss and blocking of services due to handover delay, To alleviate these drawbacks this thesis proposes a vertical handover procedure between WLAN and UMTS, which is based on MAP of HMIPv6, Performance of the proposal is evaluated in terms of blocking probabilities, The proposed procedure based on HMIPv6 shows better performance than those based on MIP.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.5B
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• pp.264-273
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• 2005

Nowadays the integration of heterogeneous wireless networks become a hot issue in communications research area. Especiall,y, 3G and WiBro interworking will be introduced soon as users can be offered the most suitable service according to service area and service providers can reduce network construction and operation expenses. In this paper, we propose an interworking scheme for fast handoff between 3G and WiBro networks. The SCI (Smoothly Coupled Integration) scheme proposed in this paper takes advantages of the existing LCI (Loosely Coupled Integration) and TCI (Tightly Coupled Integration) scheme and can offer seamless services by providing fast handoff between 3G and WiBro although each network may work independently. Through extensive computer simulations using OPNET, the efficiency of the proposed scheme has been validated.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.160-165
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• 2007

무선 센서 망에서 다중싱크 이동성에 관련된 연구는 단순히 독립된 단일싱크 이동성 확장에 기인한다. 하지만, 다중 싱크의 경우 싱크 상호간의 이동 결집도에 따라 두 가지 그룹으로 분류될 수 있다: 싱크간의 산재된 싱크그룹(loosely coupled sink group)과 밀집된 싱크그룹(tightly coupled sink group)이다. 전자는 기존 다중싱크 연구에서 가정하고 있는 일반적인 모델이다. 반면, 후자의 예로는 전쟁터에서 동일한 작전을 수행하는 작은 분대 단위의 군인들의 이동성 등이 있다. 본 논문은 밀집된 싱크그룹 이동성을 갖는 다중 싱크를 위한 데이터전달 프로토콜을 제안한다.

• Proceedings of the Korea Contents Association Conference
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• 2009.05a
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• pp.677-681
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• 2009

The Smoothly Coupled Integration (SCI) proposed in this paper takes only the strength of loosely coupled integration and tightly coupled integration. Furthermore, 3G network and WiBro network, which are coupled with SCI, have independent architecture which supports mobility and seamless services by fast handoff. Computer simulation with the use of OPNET marked excellence in performance of smoothly coupled integration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.5B
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• pp.268-274
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• 2008

With the advances in wireless communication technologies, mobile users require to get seamless services anywhere and anytime. To relize these demands, network interworking and vertical handover are necessary between heterogeneous wireless access technologies with multi-interface mobile station. A lot of organizations are doing research on the network integration schemes based on loosely and tightly integrated architectures, and research on vertical handover schemes mainly based on Mobile IP in loosely integrated environments. But actually, the tightly integrated scheme can support more faster vertical handover because heterogeneous access networks are combined tightly. However, vertical handover schemes in tightly integrated environments are conceptually proposed without any detail signaling procedures. Therefore, this paper defines a tightly integrated architecture between UMTS and WLAN, and proposes a soft vertical handover signaling procedure. The proposed soft vertical handover scheme is evaluated by the OPNET simulator, and we confirm the proposed scheme can support seamless services.

• Journal of Communications and Networks
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• v.11 no.3
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• pp.306-317
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• 2009

We consider the problem of architecting a reliable content delivery system across an overlay network using TCP connections as the transport primitive. We first argue that natural designs based on store-and-forward principles that tightly couple TCP connections at intermediate end-systems impose fundamental performance limitations, such as dragging down all transfer rates in the system to the rate of the slowest receiver. In contrast, the ROMA architecture we propose incorporates the use of loosely coupled TCP connections together with fast forward error correction techniques to deliver a scalable solution that better accommodates a set of heterogeneous receivers. The methods we develop establish chains of TCP connections, whose expected performance we analyze through equation-based methods. We validate our analytical findings and evaluate the performance of our ROMA architecture using a prototype implementation via extensive Internet experimentation across the PlanetLab distributed testbed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.10B
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• pp.845-853
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• 2003

It is expected that wireless LANs will substitute wired LANs and will be tightly coupled with mobile cellular systems. In this integrated network environment, vertical handoff between wireless LANs and mobile cellular systems is needed. In this paper, we propose handoff procedures and requirements for implementing of the vertical handoff. The proposed vertical handoff procedures are likely to be use as a basic example lot implementing of the vertical handoff.