• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.5B
• /
• pp.264-273
• /
• 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 Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.757-760
• /
• 2012

Cloud storage system that cloud computing providers provides large amounts of data storage and processing of cloud computing is a key component. Large vendors (such as Facebook, YouTube, Google) in the mass sending of data through the network quickly and easily share photos, videos, documents, etc. from heterogeneous devices, such as tablets, smartphones, and the data that is stored in the cloud storage using was approached. At time, growth and development of the globally data, the cloud storage business model emerging is getting. Analysis new network storage cloud storage services concepts and technologies, including data manipulation, storage virtualization, data replication and duplication, security, cloud computing core.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.6
• /
• pp.387-396
• /
• 2014

Recently, there have been continuous efforts and progresses regarding the research on diverse network control and management platforms for SDN (Software Defined Networking). SDN is defined as a new technology to enable service providers/network operators easily to control and manage their networks by writing a simple application program. In SDN, incomplete or malicious programmable entities could cause break-down of underlying networks shared by heterogeneous devices and stake-holders. In this sense, any misunderstanding or diverse interpretations should be completely avoided. This paper proposes a new framework for SDN application verification and a prototype based on the formal method, especially with process algebra called pACSR which is an extended version of Algebra of Communicating Shared Resources (ACSR).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.11C
• /
• pp.955-962
• /
• 2008

Multicast Strategy is one of the cost-saving methods in the large scale VOD environment. However, it does involve complicated problems to implement VCR-like interactions for user's convenience in the multicast streaming system under considering the limited-server and the network's bandwidth in the multicast-transmission system. Therefore, the proper solution of settling such a problem is necessary. Thus, this paper which revised P2Patching[l] proposes LGST(Level Group Streaming Technique) which supports the VCR's function through cooperation among peers with heterogeneous bandwidth under the environment of P2P. This strategy can reduce latency by improving the acceptance of server and using the bandwidth of network efficiently. And for evaluate the proposed scheme's performance, I simulated the performance of streaming delivery topology and streaming quality in comparison with P2Patching. In evaluation to service request refusal ratio and service quality according to bandwidth decrement, the result of simulation shows that proposed LGST improves about $11{\sim}18%$ of performance than P2Patching. In the test of latency recovery according to fault probability and influence of VCR function operation duration, it shows similar performance.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.18 no.12
• /
• pp.2847-2856
• /
• 2014

It is necessary for maritime multi-band networks, which provide ships with diverse and seamless multimedia services, to perform vertical handover. As IEEE 802.21 WG has standardized vertical handover technologies for terrestrial wireless networks that do not consider VHF, HF, satellite networks, they cannot be directly applied to maritime multi-band networks. In this paper, the vertical handover framework for use in maritime mutlti-band networks is proposed, which includes the logical architecture, the communication reference model, re-defined handover primitives, and the handover process. The proposed vertical handover for maritime multi-band network can be applied in the ocean alone, as well as to the heterogeneous wireless networks which embrace both terrestrial and maritime networks.

• The KIPS Transactions:PartC
• /
• v.9C no.2
• /
• pp.213-220
• /
• 2002

Distributed competing system gives a new system architecture to be taken into consideration for solving the problems of interoperability of heterogeneous systems. In the present paper, CORBA based on multi-threaded interoperates with software blocks at physically isolated hardware. We show how archives optimal CORBA system from analysis of required functions, implementations of protocols and benchmarking of system performance in the Open Multi-service Network System Environment. The core features of our CORBA system are restricted Quality of Service based on priority, timeout service and exception status information notify to the related software blocks. And the objectives are design and implementation of high performance multi-threaded middleware and satisfied with extendibility, flexibility and stability of CORBA platform.

• Journal of KIISE:Software and Applications
• /
• v.26 no.11
• /
• pp.1298-1305
• /
• 1999

네트워크 및 분산 처리 기술의 발달로 분산 환경에서 동작하는 응용 프로그램에 대한 생산성 향상이 요구되고 있다. 본 논문에서는 MVC(Model, View, Controller) 패턴을 기반으로 하는 분산 응용 프로그램의 생산성 향상을 위해, 조립식 분산 응용의 작성을 지원하는 분산 객체 조립기, DOC(Distributed Object Composer)를 소개한다. 분산 객체 조립성의 기반이 되는 DOC의 구성적{{) '전체'를 창조해 내기 위해 여러 요소들을 결합, 배치하여 하나의 예술작품을 성립시키는 방법. 모아서 조립한다는 의미.}} 인터페이스(Structural Interface)는 기존 객체지향 기술의 절차적 인터페이스(Procedural Interface)에 비해 콤포넌트 재사용성을 개선하고, 분산 응용의 신속한 개발을 지원하여, 소프트웨어의 생산성 및 확장성을 향상시킨다. 또한, DOC 방식으로 모델링하고 구현한 공급망 관리(Supply Chain Management: SCM) 응용 프로그램의 조립식 작성을 통해, DOC의 실시간 정보 처리 및 조립 기능을 보인다.DOC는 이질적인 통신 환경에서 클라이언트와 서버 객체간의 네트워크 투과성을 제공하는 미들웨어, CORBA를 기반으로 한다. 또한, 분산 객체들 간의 상호작용을 자동 처리하기 위해 Java의 관찰자/피관찰자(Observer/Observable)를 확장한 분산 관찰자/피관찰자 패턴을 정의하여 DOC와, 서버 및 클라이언트의 분산 응용 객체들을 정의하기 위한 인터페이스에 적용한다.Abstract Due to the availability of advances in network and distributed processing technologies, the enhanced productivity of application software that runs on distributed environment is demanded. In this paper, we introduce the Distributed Object Composer (DOC) that supports the structural composition of distributed applications for the enhanced productivity of MVC (Model, View, Controller) pattern-based application programs. The structural interface of DOC that is the basis for the composibility of distributed objects increases the reusability of software components and provides better software productivity and extendibility than the procedural interface of the traditional object-oriented technology by supporting rapid constructions of distributed applications. In this paper, we also discuss the real-time information processing and composibility features of DOC by applying the DOC mechanism to the Supply Chain Management (SCM) application.DOC is implemented using the CORBA middleware that supports the network transparency between client and server objects on heterogeneous communication environments. We apply the distributed Observer/Observable pattern that extends the Observer/Obseverable of Java to DOC itself and distributed client/server objects as their interface definitions for the automatic interactions of distributed objects.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.11 no.5
• /
• pp.897-905
• /
• 2007

In this paper, we present a new framework and synchronization mechanism to effectively support developing real-time communication service by using a real-time object model named TMO (Time-Triggered Message-Triggered Object). Also, we describes the application environment as the DHS(distributed high-precision simulation) to guarantee real-time service message with TMO structure in distributed network systems. The TMO scheme is aimed for enabling a great reduction of the designer's effort in guaranteeing timely real-time communication service capabilities of among distributed multi-nodes systems. Our real-time framework provide the consistent construction and configuration of tine-triggered processing components across heterogeneous distributed object environment more easily. It has been formulated from the beginning with the objective of enabling design-time guaranteeing of timely action. In the real time simulation techniques based on TMO object modeling, we have observed several advantages to the TMO structuring scheme. TMO object modeling has a strong traceability between requirement specification and design.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.17 no.2
• /
• pp.103-114
• /
• 2007

The existing handover authentication schemes have authentication delay and overhead of the authentication server since they have been separately studied handover authentication at the link layer and the network layer. This paper proposes a handover authentication scheme initiated by Mobile Node on FMIPv6 based mobile access networks. The main idea of the paper is to generate a session key at the mobile node side, and transfer it to the next Access Router through the authentication server. Also, the scheme has a hierarchical key management at access router. There are two advantages of the scheme. First, the generated session key can be utilized for protecting the binding update messages and also for access authentication. Second, hierarchical key management at the access router reduced the handover delay time. The security aspects on the against PFS, PBS, and DoS attack of proposed scheme are discussed.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.26 no.1
• /
• pp.7-14
• /
• 2022

Sensor Registry System (SRS) has been devised for maintaining semantic interoperability of data on heterogeneous sensor networks. SRS measures the connectability of the mobile device to ambient sensors based on positions and only provides metadata of sensors that may be successfully connected. The step of identifying the ambient sensors which can be successfully connected is called sensor filtering. Improving the performance of sensor filtering is one of the core issues of SRS research. In reality, GPS sometimes shows the wrong position and thus leads to failed sensor filtering. Therefore, this paper proposes a new sensor filtering strategy using geographical embedding and neural network-based path prediction. This paper also evaluates the service provision rate with the Monte Carlo approach. The empirical study shows that the proposed method can compensate for position abnormalities and is an effective model for sensor filtering in SRS.