• ETRI Journal
• /
• v.30 no.6
• /
• pp.856-858
• /
• 2008

Odd networks were introduced in the context of graph theory. However, their potential as fault-tolerant multiprocessor networks has been shown. Broadcasting is one of the most important communication primitives used in multiprocessor networks. In this letter, we introduce efficient one-to-all broadcasting schemes of odd networks for one-port and all-port models. We show the broadcasting time of the former is 2d-2 and that of the latter is d-1. The total time steps taken by the proposed algorithms are optimal.

• ETRI Journal
• /
• v.31 no.3
• /
• pp.330-332
• /
• 2009

Broadcasting is one of the most important communication primitives used in multiprocessor networks. In this letter, we demonstrate that the broadcasting algorithm proposed by Madabhushi and others is incorrect. We introduce efficient one-to-all broadcasting schemes of even networks for one-port and all-port models. The broadcasting time of the one-port model is 2d-3 and that of the all-port model is d-1. The total time steps taken by the proposed algorithms are optimal.

• Journal of KIISE:Computer Systems and Theory
• /
• v.30 no.7_8
• /
• pp.359-369
• /
• 2003

We present efficient generalized algorithms for all-to-all personalized communication operations in a 2D torus. All-to-all personalized communication, or complete exchange, is at the heart of numerous applications, such as matrix transposition, Fast Fourier Transform(FFT), and distributed table lookup. Some algorithms have been Presented when the number of nodes is power-of-2 or multiple-of-four form, but there has been no result for general cases yet. We first present complete exchange algorithm called multiple-Hop-2D when the number of nodes is in the form of multiple-of-two. Then by extending this algorithm, we present two algorithms for an arbitrary number of nodes. Split-and-Merge algorithm first splits the whole network into zones. After each zone performs complete exchange, merge is applied to finish the desired complete exchange. By handling extra steps in Double-Hop-2D algorithm, Modified Double-Hop-2D algorithm performs complete exchange operation for general cases. Finally, we compare the required start-up time for these algorithms.

• Journal of the Korea Institute of Military Science and Technology
• /
• v.21 no.6
• /
• pp.826-841
• /
• 2018

The military satellite communication of ROK military, ANASIS is designed for analog data such as voice and streaming data. ANASIS cannot fully support ALL-IP communications due to its long propagation delay. The next generation satellite communication system is being designed to overcome the limitation. Next generation satellite communications system considers both high-speed and low-speed networks to support various operating environment. The low-speed satellite supports both broadband and narrow-band communication. This network works as the infrastructure for of wide-area internetworking over multiple AS's in the terrestrial network. It requires minimum satellite frequency and minimum power and works without PEP and router. In this paper, we propose a network operation structure to enable the inter-operation between high and low-speed satellite networks. In addition, we propose a data link protocol for low speed satellite networks.

• Journal of the Optical Society of Korea
• /
• v.19 no.5
• /
• pp.437-443
• /
• 2015

In this paper, we analyze the performance of the all-optical multihop radio over a free space optical (RoFSO) communication system with amplify-and-forward (AF) relays under varying weather conditions. The proposed channel model considers the propagation loss, attenuation and atmospheric fading modeled by the Gamma-Gamma (GG) distribution. Both the amplified spontaneous emission (ASE) noise in the all-optical relays and the background noise projected onto receiver apertures have been considered in the analysis. The lower bound analytical expressions for the end-to-end bit error rate (BER) and outage probability are derived for the multihop system employing the all-optical relays with the full channel state information (CSI). Meanwhile, the exact results for BER and outage probability are obtained via Monte Carlo simulation. Results indicate the performance of the proposed system will be improved by the multihop transmission technology. For a fixed number of relays, the BER and outage probability will be increased with the deterioration of the weather conditions.

• 제어로봇시스템학회:학술대회논문집
• /
• 1997.10a
• /
• pp.1271-1274
• /
• 1997

The industrial automation market encompasses all aspects of the discrete process in the manufactring industries. Nowadays many manufacturers are increasingly moving to increase plant capacity, and are trying to produce better quality at the lower costs. We have studied a modern projection-automation system to achieve the communication network which makes connection among all of the projection machines and connect them to a central computer. This communication system have to be very flexible and fast. Also we have studied the communication interface for the automatic production system including the hardware elements and the communication software.

• Journal of the Korean Society for Railway
• /
• v.16 no.3
• /
• pp.189-195
• /
• 2013

Recent trains have broadband train communication networks to improve train operation safety and to provide passengers with multimedia services. Compared to glass optical fiber, plastic optical fiber (POF) has a large diameter; it also provides the good durability and maintainability necessary to railway applications. This paper suggests an All-IP broadband train communication network that connects all devices in the train through a POF interface. Performance tests according to Korean railroad standards shows that this POF interface is usable in the range of vibration and temperature conditions encountered in trains. A dedicated Layer-2 switch with the POF interface is developed for the construction of the All-IP train communication network. A prototype 1Gbps train communication network was set up in a trial-run of train on a metro line using the developed Layer-2 switch and POF. On-track tests indicated the feasibility of the POF train communication network. POF has an additional advantage of economic feasibility, and it is expected to start a trend toward broadband train communication networks using POF.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2002.04b
• /
• pp.1459-1462
• /
• 2002

3GPP(Third Generation Partnership Project)와 3GPP2 등의 국제 표준화 기구에서는 초기 IMT-2000 망 구조로부터 All IP 망으로 진화할 것으로 예상하고 있다. 이에 본 논문에서는3GPP와 3GPP2를 중심으로 All IP 망의 기존에 제시된 All IP 망의 진화 시나리오를 분석하고, 이를 바탕으로 기존 PSTN/ISDN 연동, VoIP, Mobile IP 등과 같은 새로운 기술, 기존회선 모드 단말기 수용 등을 고려한 All IP 진화 시나리오에 따른 단계별 망 구조를 제시한다.

• Journal of KIISE:Computer Systems and Theory
• /
• v.27 no.5
• /
• pp.464-474
• /
• 2000

All-to-all personalized communication, or complete exchange, is at the heart of numerous applications, such as matrix transposition, fast Fourier Transform(FFT), and distributed table lookup.We present an efficient all-to-all personalized communication algorithm for a 2D torus inwormhole-routed networks. Our complete exchange algorithm adopts divide-and-conquer approach toreduce the number of start-up latency significantly, which is a good metric for network performancein wormhole networks. First, we divide the whole network into 2x2 basic cells, After speciallydesignated nodes called master nodes have collected messages to transmit to the rest of the basic cell,only master nodes perform complete exchange with reduced network size, N/2 x N/2. When finishedwith this complete exchange in master nodes, these nodes distribute messages to the rest of the masternode, which results in the desired complete exchange communication. After we present our algorithms,we analyze time complexities and compare our algorithms with several previous algorithms. And weshow that our algorithm is efficient by a factor of 2 in the required start-up time which means thatour algorithm is suitable for wormhole-routed networks.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• v.9 no.1
• /
• pp.864-867
• /
• 2005

All-optical networks are emerging as a promising technology for per second class communication. However, they are intrinsically different from electro-optical networks, particularly because they do not regenerate signals in the networks. The characteristics of all-optical network components and architectures manifest and still unstudied security vulnerabilities but also offer a new array of possible countermeasures. In this paper, we have analysed the security issue to protect against intrusion.