• Journal of KIISE:Computer Systems and Theory
• /
• v.26 no.11
• /
• pp.1401-1413
• /
• 1999

ATM over xDSL으로 구성된 광대역 가입자 망을 통하여, ATM 망에 접속하려 할 때에는 DSL 접근 다중화기(Access Multiplexer)가 필수적으로 요구된다. 이 때 광대역 통합 서비스라는 가입자 망의 기본적인 목적을 달성하기 위하여, DSL 접근 다중화기는 ATM 계층에서의 트래픽 제어를 수행할 수 있어야 한다. 이에 본 논문에서는 DSL 접근 다중화기에서의 트래픽 제어에 필요한 효율적이고 간단한 셀 스케쥴링 기법을 제안한다. 성능평가를 위한 모의실험에 의하면, 제안된 기법은 각 연결들에게 그들의 트래픽 기술자에 부합하는 서비스를 제공할 수 있으며, 아울러 연결들이 명세한 셀 손실률에 근거하여 차별화 된 서비스 품질(QoS)을 제공할 수 있다.Abstract When residential users access core network via ATM over xDSL, DSL Access Multiplexer(DSLAM) which processes ATM cells transmitted from customer premises, is indispensable. In order to fulfill original goal of residential broadband integrated service, DSLAM should be able to perform ATM layer traffic management, mainly QoS(Quality of Service) provision. In this paper, we propose an efficient and simple cell scheduling scheme applicable to access multiplexer such as DSLAM. According to simulations for performance evaluation, the proposed cell scheduling scheme is able to supply bandwidths conforming to traffic descriptors of the connections. Moreover it is verified that the proposed scheme has a CLR based connection discrimination capability.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.19 no.4
• /
• pp.633-638
• /
• 1994

Asynchronous Transfer Model(ATM) has a fixed-length packet transport scheme. It is one of promising proposals in Broadband ISDN(B-ISDN). Since the packet length is fixed, it can be potentially to perform the various service to user. In this paper, a queueing model for an ATM Multiplexer loaded by the Continuous Bit Rate(CBR) traffic and the bursty traffic sources is analyzed. The queueing system has a finite buffer size. The cell loss probabilities with the simple and recurcive form for a performance measures of ATM multiplexer are derived, and are also evaluated through numerical examples. The results of this study may be used as guidelines in buffer design problems and performance analysis of ATM multiplexing system.

• IEMEK Journal of Embedded Systems and Applications
• /
• v.14 no.6
• /
• pp.313-319
• /
• 2019

Finite field operations have played an important role in error correcting codes and cryptosystems. Recently, the necessity of efficient computation processing is increasing for security in cyber physics systems. Therefore, efficient implementation of finite field arithmetics is more urgently needed. These operations include addition, multiplication, division and inversion. Addition is very simple and can be implemented with XOR operation. The others are somewhat more complicated than addition. Among these operations, multiplication is the most important, since time-consuming operations, such as exponentiation, division, and computing multiplicative inverse, can be performed through iterative multiplications. In this paper, we propose a multiplexer based parallel computation algorithm that performs Montgomery multiplication over finite field using redundant basis. Then we propose an efficient multiplexer based semi-systolic multiplier over finite field using redundant basis. The proposed multiplier has less area-time (AT) complexity than related multipliers. In detail, the AT complexity of the proposed multiplier is improved by approximately 19% and 65% compared to the multipliers of Kim-Han and Choi-Lee, respectively. Therefore, our multiplier is suitable for VLSI implementation and can be easily applied as the basic building block for various applications.

• Journal of IKEEE
• /
• v.12 no.1
• /
• pp.43-50
• /
• 2008

In this paper, the output and temperature characteristics for an optical signal of the fiber bragg grating have been considered. Also, output characteristics which depend on the temperature changes have been investigated for an all-optic add/drop multiplexer based on the fiber bragg grating and Mach-Zehnder interferometer. From the obtained results, they show that the center wavelength of output spectrum shifts approximately 0.01230 nm/$^{\circ}C$ within a temperature range $-30^{\circ}C{\sim}90^{\circ}C$.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.289-291
• /
• 2007

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the uses by the various portable terminals in the mobile environment. Integrated complex reception platform is required to receive multimedia broadcasting services transmitted from various transmission media. In this paper, we present the design and implementation technic for providing the both of terrestrial and satellite DMB services simultaneously using the same hardware platform. The implemented complex receiving terminal to accommodate these DMB services simultaneously need composed of it RF module. it baseband module, it complex control module and the complex de-multiplexer module. The complex control module is designed using uClinux operating system. The complex de-multiplexer, which perform the functions of the address decoder and each DMB stream de-multiplexer, is implemented. with FPGA device. The implemented platform is tested in a real environment and its performance is satisfied with required performance criteria.

• Journal of Korean Institute of Industrial Engineers
• /
• v.23 no.1
• /
• pp.23-37
• /
• 1997

In this paper, performance analysis of video traffic shaper for Motion Picture Experts Group (MPEG) video traffic in on ATM network are investigated. Traffic shaping for MPEG video traffic is proposed as a traffic control function in ATM networks. The proposed shaper smoothes video traffics by controling the output rate of the buffer, which is placed in an MPEG source, according to I,B,P frame sequences of MPEG. In performance analysis of an video traffic shaper, a periodic botch arrival model is suggested to describe cell streams in a frame of MPEG video traffic. The queueing model which has periodic independent botch arrival and periodic deterministic service time is used to obtain the cell loss ratio, the mean cell delay, and the measure of smoothing effect. Simulation results are used to validate this queueing model. The cell loss performance of ATM multiplexer is measured by simulation study with real MPEG-1 data. From the viewpoint of traffic load, the cell loss ratio is observed to be considerably high, which is considered to result from the burstiness of MPEG video traffic. As a result, it is shown that the shaping decreases cell loss ratio of multiplexer. The results of this paper can be employed to establish a basic guideline in the implementation of a traffic control scheme and the design of ATM multiplexer for MPEG video traffic.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.31 no.10A
• /
• pp.1020-1030
• /
• 2006

As the Terrestrial DMB(T-DMB) has been launched, service providers are focusing on finding a business model as well as preparing the variety of data services. So, the need for development of the CAS(Conditional Access system) is urgently required and its domestic standardization is also in progress. This Paper proposes design and implementation methods of an Ensemble Re-multiplexer and receiver platform for its verification that can be used for the CAS system in T-DMB. And, with transmitting ensemble stream scrambled by the proposed Ensemble Re-multiplexer, we verified their performance by do-scrambling and decoding according to scramble mode at the receiver platform.

• Journal of KIISE:Information Networking
• /
• v.28 no.3
• /
• pp.417-425
• /
• 2001

Since First-Come-First-Served discipline makes it difficult to satisfy the diverse quality of scrvicc(QoS) requirements for each c-oonection, traffic isolation has been proposed for guaranteeing the desired QoS through explicit bandwidth allocation to each virtual connection(VC) in A TM networks. For this purpose, we propose a rate-controlled cell multiplexer using a simple "periodic token-based regulator" per- Vc. The proposed multiplexer realizes VC isolation, while still operating work'||'&'||'not;conservingly. We first discuss its major properties, and then examine its features with respect to the characteristics of the output traffic streams and the traffic isolation of individual VC's, by simulation.n.

• ETRI Journal
• /
• v.31 no.6
• /
• pp.770-777
• /
• 2009

We have developed a fully functional reconfigurable optical add-drop multiplexer (ROADM) switch module using a polymer integrated photonic lightwave circuit technology. The polymer variable optical attenuator (VOA) array and digital optical switch array are integrated into one polymer PLC chip and packaged to form a 10-channel VOA integrated optical switch module. Four of these optical switch modules are used in the ROADM switch module to execute 40-channel switching and power equalization. As a wavelength division multiplexer (WDM) filter device, two C-band 40-channel athermal arrayed waveguide grating WDMs are used in the ROADM module. Optical power monitoring of each channel is carried out using a 5% tap PD. A controller and firmware having the functions of a 40-channel switch and VOA control, optical power monitoring, as well as TEC temperature control, and data communication interfaces are also developed in this study.

• Journal of Internet Computing and Services
• /
• v.7 no.2
• /
• pp.81-92
• /
• 2006

Recently, the number of mobile phone and PDA users has been rapidly increased. Such monitoring and control applications as geographical and traffic information systems are being used widely with wireless devices. In this paper, we introduce the mobile M/VC application framework that supports the rapid constructions of mobile monitoring and control (M/VC) applications. The mobile M/VC application framework uses the mobile Observer/Observable pattern that extends the Java's Observer/Observable for automatic interactions of server and client objects in wireless environments. It also provides the Multiplexer and Demultiplexer classes that supports the assembly feature of Observer and Observable objects. To construct an application using the framework, developers just need to create necessary objects from the Observable and MobileObserver classes and inter-connect them structurally(like the plug-and-play style) through the Multiplexer and Demultiplexer objects. Then, the state change of Observable objects is notified to the connected Observer objects and user's input with Observer objects is propagated to Observable objects. These mechanism is the main process for monitoring and control applications. Therefore, the mobile M/VC application framework can improve the productivity of mobile applications and enhance the reusability of such components as Observer and Observable objects in wireless environments.