• 한국통신학회논문지
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• 제22권2호
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• pp.280-290
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• 1997

The Single TTCN has been broadly used to describe the ATS(Abstract Test Suite) for the protocol confronance testing. But if the single TTCN is used to test the multi-party protocol with the non-deterministic factors, then huge amount of test notations are needed and also it is hard to understand the ATS. Therefore, the concurrent TTCN was proposed to solve these problems and the study in progress. In this paper, we did investigate and compare the characteristics of esisting single TTCN with those of the concurrent TTCN. In order to develop the ATS of the Q.2971 which is B-ISDN call/connection control protocol, the testing model was defined and the concurrent factors were extracted according to that model. As a result, we could verify the usefulness of the confcurrent TTCN.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권3호
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• pp.778-798
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• 2014

This paper proposes a novel exposed-terminal-eliminated medium access control (ETE-MAC) protocol by combining channel reservation, collision avoidance and concurrent transmissions to improve multi-access performance of the multihop wireless networks. Based on the proposed slot scheduling scheme, each node senses the control channel (CCH) or the data channel (DCH) to accurately determine whether it can send or receive the corresponding packets without collisions. Slot reservation on the CCH can be simultaneously executed with data packet transmissions on the DCH. Therefore, it resolves the hidden-terminal type and the exposed-terminal type problems efficiently, and obtains more spatial reuse of channel resources. Concurrent packet transmissions without extra network overheads are maximized. An analytical model combining Markov model and M/G/1 queuing theory is proposed to analyze its performance. The performance comparison between analysis and simulation shows that the analytical model is highly accurate. Finally, simulation results show that, the proposed protocol obviously outperforms the link-directionality-based dual-channel MAC protocol (DCP) and WiFlex in terms of the network throughput and the average packet delay.

• 한국컴퓨터정보학회논문지
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• 제6권2호
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• pp.84-89
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• 2001

본 논문은 근거리 통신망 (LAN)의 종단에서 사용되는 기존의 멀티링크 스위칭 기법이 최대 정규화 전파 지연 값이 커질수록 채널 이용률이 급격히 떨어지는 단점이 있어 이를 보완하고자 병행처리 기능을 추가하여 프로토콜을 개선시킨 다음에 성능을 분석하여 보았다. 개선된 프로토콜의 성능 분석은 채널 이용률 관점에서 이루어졌으며 이것을 기존의 다른 프로토콜과 비교하여 보았다. 그 결과 병행처리 기능이 추가된 프로토콜이 기존의 여러 방식의 프로토콜보다 최대 정규화 전파 지연 값이 커질 경우 더 나은 성능을 보임을 알 수 있었다.

• 디지털산업정보학회논문지
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• 제11권3호
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• pp.79-90
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• 2015

Multipath routing technique is recognized as one of the effective approaches to improve the reliability of data forwarding. However, the traditional multipath routing focuses only on how many paths are needed to ensure a desired reliability. For this purpose, the protocols construct additional paths and thus cause significant energy consumption. These problems have motivated the study for the energy-efficient and reliable data forwarding. Thus, this paper proposes an energy-efficient concurrent multipath routing protocol with a small number of paths based on interaction between paths. The interaction between paths helps to reinforce the multipath reliability by making efficient use of resources. The protocol selects several nodes located in the radio overlapped area between a pair of paths as bridge nodes for the path-interaction. In order to operate the bridge node efficiently, when the transmission failure has detected by overhearing at each path, it performs recovery transmission to recover the path failure. Simulation results show that proposed protocol is superior to the existing multipath protocols in terms of energy consumption and delivery reliability.

• 문화기술의 융합
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• 제10권6호
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• pp.799-805
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• 2024

최근 생성형 인공지능(AI) 기술이 빠르게 발전하며 글자인식, 음성인식, 영상인식, 사물인식, 시계열적인 예측, 자연어처리 분야뿐만 아니라 인공지능이 할 수 없을 것이라고 생각했던 창의적 디자인 영역까지 그 적용 분야가 확대되고 있다. 우리는 생성형 인공지능을 활용하는 패턴 디자이너의 인지적 모형을 연구하기 위한 탐색적 접근을 목적으로 한다. 이를 위해 생성형 인공지능 가운데 제일 인지도가 높은 챗 GPT를 활용하여 패턴 디자인 과정을 인지과학적 연구방법인 프로토콜 분석 방법을 적용하였다. 4명의 디자인 대학원생을 피험자로 선정하며 예행연습과 본 실험을 실시하였다. 데이터 수집을 위하여 음성녹음과 동영상 캡처를 수행하였다. 프로토콜 방법은 과제를 수행하면서 자신의 머릿속에서 생각나는 것을 말로 동시에 표현하는 동시조서(Concurrent Protocol) 방법을 적용하였다. 수집된 구두 데이터를 활용하여 어휘분절하여 디자인 과정을 분류하며 코딩스킴을 개발하여 분석의 틀을 마련하였다. 그 결과, 분석, 선택, 시각화, 평가, 최적화가 발견되었다. 우리는 패턴디자인 실무를 위한 디자인 가이드라인을 제시할것으로 기대한다.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2005년도 추계 학술발표대회 논문집
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• pp.214-215
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• 2005

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.135-138
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• 2008

순차적으로 동기화를 처리하던 기존의 동기화 프로토콜은 다수의 클라이언트에 대해 뒤에 요청된 동기화 작업들이 대기하는 문제가 발생한다. 이 논문에서는 순차적 동기화로 발생하는 대기시간을 감소시킬 수 있는 동시 동기화 프로토콜을 구현하였다. 서로 다른 동기화 작업 간 변경충돌이 없는 경우 동시 동기화 프로토콜은 다중 큐를 이용하여 라운드 로빈 방식으로 동기화작업을 진행하여 대기 시간을 감소시킨다.

• Journal of Communications and Networks
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• 제12권3호
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• pp.275-284
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• 2010

The current multihome-aware protocols (like stream control transmission protocol (SCTP) or parallel TCP for concurrent multipath data transfer (CMT) are not designed for high-capacity and large-latency networks; they often have performance problems transferring large data files over shared long-distance wide area networks. It has been shown that SCTP-CMT is more sensitive to receive buffer (rbuf) constraints, and this rbuf-blocking problem causes considerable throughput loss when multiple paths are used simultaneously. In this research paper, we demonstrate the weakness of SCTP-CMT rbuf constraints, and we then identify that rbuf-blocking problem in SCTP multihoming is mostly due to its loss-based nature for detecting network congestion. We present a simulation-based performance comparison of FAST TCP versus SCTP in high-speed networks for solving a number of throughput issues. This work proposes an end-to-end transport layer protocol (i.e., FAST TCP multihoming as a reliable, delaybased, multihome-aware, and selective ACK-based transport protocol), which can transfer data between a multihomed source and destination hosts through multiple paths simultaneously. Through extensive ns-2 simulations, we show that FAST TCP multihoming achieves the desired goals under a variety of network conditions. The experimental results and survey presented in this research also provide an insight on design decisions for the future high-speed multihomed transport layer protocols.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2012년도 한국컴퓨터종합학술대회논문집 Vol.39 No.1(D)
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• pp.187-189
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• 2012

The medium access control (MAC) protocol is designed only for single channel in the IEEE 802.11 standard. That means the throughput of the network is limited by the bandwidth of the single channel. The multiple channels can be exploited to get more concurrent transmission. In this paper, we propose a novel Multi-channel MAC that utilizes the channel more efficiently than other Multi-channel MAC protocols.

• Journal of Communications and Networks
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• 제11권3호
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• pp.287-296
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• 2009

Although asymptotic bounds of wireless network capacity have been heavily pursued, the answers to the following questions are still critical for network planning, protocol and architecture design: Given a three-dimensional (3D) network space with the number of active users randomly located in the space and using the wireless communication technology, what are the expected per-flow throughput, network capacity, and network transport capacity? In addition, how can the protocol parameters be tuned to enhance network performance? In this paper, we focus on the ultra wideband (UWB) based wireless personal area networks (WPANs) and provide answers to these questions, considering the salient features of UWB communications, i.e., low transmission/interference power level, accurate ranging capability, etc. Specifically, we demonstrate how to explore the spatial multiplexing gain of UWB networks by allowing appropriate concurrent transmissions. Given 3D space and the number of active users, we derive the expected number of concurrent transmissions, network capacity and transport capacity of the UWB network. The results reveal the main factors affecting network (transport) capacity, and how to determine the best protocol parameters, e.g., exclusive region size, in order to maximize the capacity. Extensive simulation results are given to validate the analytical results.