• Journal of the Korea Institute of Information Security & Cryptology
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• v.25 no.6
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• pp.1411-1420
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• 2015

Lawful interception(LI) standard of telephone networks has technical limitations to lawfully intercept IMS/SIP-based mobile communication network subscriber who using Android and iPhone device. In addition, the technical standards related to legal interception of the IMS/SIP of the wireless network is insufficient compared to the systematic study of the development of a wireless network infrastructure. The architecture proposed in the standard of ETSI(European Telecommunications Standards Institute) for the seamless LI is insufficient to overcome the limitations of traditional voice-centric LI techniques. This paper proposes an IMS/SIP-based architecture to perform LI under 3G networks that focuses on mobility-supported environments with merging cellular networks and the Internet. We implemented the simulation to verify the efficiency of the proposed architecture, and the experimental results show that our method achieves higher lawful interception rate than that of existing interception methods.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.3C
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• pp.102-111
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• 2005

In this paper, we propose an advanced hardware architecture for the fast inter prediction engine of the video coding standard MPEG-4 AVC. We describe the algorithm and derive the hardware architecture emphasizing and real time operation of the quarter_pel based motion estimation. The fast inter prediction engine is composed of block segmentation, motion estimation, motion compensation, and the fast quarter_pel calculator. The proposed architecture has been verified by ARM-interfaced emulation board using Excalibur & Virtex2 FPGA, and also by synthesis on Samsung 0.18 um CMOS technology. The synthesis result shows that the proposed hardware can operate at 62.5MHz. In this case, it can process about 88 QCIF video frames per second. The hardware is being used as a core module when implementing a complete MPEG-4 AVC video encoder chip for real-time multimedia application.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.205-209
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• 2000

Modem wireless communication equipments provides various multimedia and aims at the development of low-power, minimum size and weight, and low-cost implimentations. Because of the heterodyne architecture which was invented many decades ago in the wireless communication system using too many components, it was difficult to make it small, compact and On-Chip so it does not proper for future communication. That gives rise a new developing architecture, so called, Direct Conversion. Because The Direct Conversion down-converts the wireless frequency band to baseband directly, it does not need using additive components and has a merit of reduction in power dissipation. We describes the Direct Conversion architecture and DC-Offset, which must be solved, theorectically and predicts system performance enhancement when adopt the AC-Coupling method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.8C
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• pp.793-800
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• 2005

Computation of multimedia data increases in portable devices with the advances of the mobile and personal communication services. The energy management of such devices is very important for the battery-powered operation hours. The motion estimation in a video encoder requires huge amount of computation, and hence, consumes the largest portion of the energy consumption. In this paper, we propose a novel architecture that a low energy management scheme can be applied with several fast-search algorithms. The energy-constrained Vdd hopping (ECVH) technique reduces power consumption of the motion estimation by adaptively changing the search algorithm, the operating frequency, and the supply voltage using the remaining slack time within given power-budget. We show that the ECVH can be applied to the architecture, and that the power consumption can be efficiently reduced.

• Journal of KIISE:Computer Systems and Theory
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• v.26 no.9
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• pp.1126-1134
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• 1999

최근 다양한 멀티미디어 서비스를 지원하기 위한 통신망 관리와 서비스 관리가 통합된 개방형 정보 통신망의 구조가 요구되고 있다. 이러한 구조를 기반으로, TINA-C(Tele-communications Information Networking Architecture-Consortium)에서는 분산 환경에서 분산 어플리케이션 객체들에 대한 복잡한 서비스 및 관리 인터페이스들을 간결하도록 객체그룹의 개념을 정의하고 있다. 이러한 환경 속에서 트레이딩 서비스는 통신 서비스를 제공하는 객체그룹간의 상호작용을 지원하는데 매우 중요하다.따라서, 본 논문에서는 객체그룹간의 상호접속을 지원할 수 있는 트레이딩 기능과 이들 트레이더들간의 연동을 위한 트레이더 연합 모델을 제시하고자 한다. 이를 위해 우리는 트레이더의 중개자로서 Cooperator를 설계하여 기존의 트레이더와 연동시켰다. 이러한 결과로서 우리의 새로운 트레이더 연합 모델에서 Cooperator는 객체그룹간의 상호접속에서 객체들의 접속 권한의 체크 기능과 기존의 트레이더 연합모델의 문제점인 트레이더들간의 단 방향 연결문제를 보완하여 양방향 연결 기능을 갖도록 하였다. 끝으로, 이러한 해결 과정을 보이기 위해 트레이더와 Cooperator들로 이루어진 본 연합모델에서 분산 객체그룹간의 상호접속 절차과정과 사건 추적 다이어그램을 보였다.Abstract Recently, the open networking architecture is required to support various multimedia services as integrated functions of network management and service management. Based on this architecture, TINA-C defines an object group concept for simplifying complex management and service interfaces, when distributed application is executed in distributed environments. Within the support environment the trading service is an important of the interacting object groups which provide a telecommunication service.Hence, we suggest the trader federation model for supporting interconnections between object groups and among existing traders by using the cooperator we designed, as an intermediator among traders. Our cooperator has functions for checking access rights of objects in object groups, and for providing bidirectional linkage among traders. Up to now, the existing trader federation models have a single directional linkage for interactions among traders. Finally, we showed the interface procedure and the event trace diagram of distributed object groups using our model consisted of traders and the cooperators.

• Journal of Korea Game Society
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• v.12 no.4
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• pp.13-22
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• 2012

The wide-spread use of the broadband Internet service makes the cloud computing-based gaming service possible. A game program is executed on a cloud node and its live image is fed into a remote user's display device via video streaming. The user's input is immediately transmitted and applied to the game. The minimization of the time to process remote user's input and transmit the live image back to the user and thus satisfying the requirement of instant responsiveness for gaming makes it possible. However, the cost to build its servers can be very expensive to provide high quality 3D games because a general purpose graphics system that cloud nodes are likely to have for the service supports a single 3D application at a time. Thus, the server must have a technology of 'realtime multiple rendering' to execute multiple 3D games simultaneously. This paper proposes a new architecture of 2-tier servers of clouds nodes of which one group executes multiple games and the other produces game's live images. It also performs a few experimentations to prove the feasibility of the new architecture.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.39 no.5
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• pp.477-485
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• 2002

In this paper, we present an efficient hardware architecture for the H.263 video codec and its VLSI implementation. This architecture is based on the unified interface by which internal hardware engines and an internal RISC processor are connected one another. The unified interface enables the modular design of internal blocks, efficient hardware/software partitioning, and pipelined paralled operations. The developed VLSI supports the H.263 version 2 profile 3 @ level 10, and moreover, both the control protocol H.245 and the multiplexing protocol H.223. Therefore, it can be used for the complete ITU-T H.324 or 3GPP 3G 324M multimedia processor with the help of an external audio codec. Simultaneous encoding and decoding of QCIF format images at a rate greater than 15 frames per second is achieved at 40 MHz clock frequency.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.10
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• pp.57-66
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• 2010

Today the various types of communication and application service are provided by the development of Internet and IP technologies. It is expected to be extended the service domain of two networks through the interconnecting P2PSIP overlay which is highlighted as an important technologies for Internet based services and IMS(IP Multimedia Subsystem) which is the new architecture adopted in the evolution of NGN. Therefore, this paper explains the possible methods of the service expansion with interconnecting P2PSIP overlay and IMS network. Specially this paper suggests the interconnection architectures of P2PSIP overlay and IMS network as subscriber's types and analyzes the traffic analysis model and session set up delay characteristics by simulation model. As a results, this paper shows that the interconnection architecture using gateway AS(Application Server) is the excellent method to interconnect the IMS in case of P2PSIP overlay only subscriber, and that interconnection architecture using I-CSCF is good method to interconnect the IMS in case of P2PSIP overlay and IMS subscriber.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.3B
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• pp.100-111
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• 2008

In this paper, to support a QoS level appropriate for the user in Wireless Home Network based Wireless LAN, we propose a QoS support architecture which includes Wired Network and Wireless Network. Actually, an important problem to support QoS in Wireless Home Network is approached not only on a MAC level in Wireless LAN but on a integrated method to combine Network layer with Datalink layer. Applying the integrated QoS support method. It is possible to provide QoS support architecture using a Wireless LAN terminal with a minimum changing, the proposed scheme has advantage of QoS support method, which is more superior than a existing scheme to support QoS in MAC level of Wireless LAN. Simulation results that overall performance of the proposed scheme can be improved.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.12B
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• pp.2262-2274
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• 1999

This paper, proposes an integrated management platform to solve various management issues for multicast environments, which have been considered as an important transfer method together the appearance of multipeer applications recently(i.e,. IPME). First of all this paper describes the problems and related works of multicast environments, and proposes the general architecture of a management platform to manage multicast environments after considering design requirements to implement a proposed platform. This paper also proposes the management services to be provided, a general system architecture, its functional modules, and the management architecture such as a management procedure, establishment phases, management policies, and a Management Information Base(MIB) structure. In order to verify the proposed IPME, it is also applied and implemented as prototyping system to the QoS management service for H.263 video encoding/decoding system, that is IPME-QoS, which currently is a critical issue and uses multicast environments.