• KSII Transactions on Internet and Information Systems (TIIS)
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• 제13권7호
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• pp.3447-3469
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• 2019

It is well-known that the cooperative communication and error control technology can improve the network performance, but most existing cooperative MAC protocols have not focused on how to cope with the contention process caused by cooperation and how to reduce the bad influence of channel packet error rate on the system performance. Inspired by this, this paper first modifies and improves the basic rules of the IEEE 802.11 Medium Access Control (MAC) protocol to optimize the contention among the multi-relay in a cooperative ARQ scheme. Secondly, a hybrid ARQ protocol with soft combining is adopted to make full use of the effective information in the error data packet and hence improve the ability of the receiver to decode the data packet correctly. The closed expressions of network performance including throughput and average packet transmission delay in a saturated network are then analyzed and derived by establishing a dedicated two-dimensional Markov model and solving its steady-state distribution. Finally, the performance evaluation and superiority of the proposed protocol are validated in different representative study cases through MATLAB simulations.

• 한국통신학회논문지
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• 제33권8B호
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• pp.689-698
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• 2008

The performance of a TCP protocol on MANETs has been studied in a numerous researches. One of the significant reasons of TCP performance degradation on MANETs is inability to distinguish between packet losses due to congestion from those caused by nodes mobility and as consequence broken routes. This paper presents the Cluster-Label-based Routing (CLR) protocol that is an attempt to compensate source of TCP problems on MANETs - multi-hop mobile environment. By utilizing Cluster-Label-based mechanism for Backbone, the CLR is able to concentrate on detection and compensation of movement of a destination node. The proposed protocol provides better goodput and delay performance than standardized protocols especially in cases of large network size and/or high mobility rate.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.676-679
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• 1997

Networking for manufacturing is gaining importance as a nerve system of computer-integrated manufacturing(CIM). Among the various network types, the most inexpensive type called fieldbus is specifically aimed to interconnect simple devices such as sensors and actuators. For this purpose, there are several choices of the protocol such as Profibus, FIP, Foundation Fieldbus, and IEC/ISA fieldbus. This paper presents the simulation results of Profibus and FIP. Both protocols has been simulated in order to evaluate the performance such as transmission delay and throughput under different protocol parameter setting and traffic conditions.

• Journal of information and communication convergence engineering
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• 제6권2호
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• pp.134-139
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• 2008

In this paper, we propose an analysis model for the performance of channel error probability in Stream Control Transmission Protocol (SCTP) using Markov model. In this model it is assumed that the compressor and decompressor work in Unidirectional Mode. And the average throughput of SCTP protocol is obtained by finding the throughputs of when the initial channel state is good or bad.

• 한국통신학회논문지
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• 제22권2호
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• pp.250-258
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• 1997

A modified IPRMA protocol using priority scheme is proposed to increase the number of maximum users, which prevents the collision between the voice and data traffic. A simple decentralized traffic control scheme is presented for the proposed protocol. The improvement in performance over conventional IPRMA is shown through simulation, and EPA(Equilibrium Point Analysis) is used to evaluate system performance.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 1998년도 The Korea Society for Simulation 98 춘계학술대회 논문집
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• pp.27-31
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• 1998

The growing usage of multimedia communication applications with specific bandwidth and real-time delivery requirements has created the needs for quality of service(QoS). In response to the growing demand for an integrated services, the Reservation Protocol(RSVP) has been designed to exchange resource reservation among routers in the internet. RSVP protocol provides the quality of service for real-time applications but the network efficiency is reduced because of the limited bandwidth. In order to use network resources efficiently. We compare the resource efficiency of traditional reservation methods with that of the proposed method and evaluate the performance of the internet phone.

• 대한전자공학회논문지TC
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• 제43권11호
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• pp.35-43
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• 2006

본 논문에서는 IETF(Internet Engineering Task Force)에서 진행 중인 NetLMM(Network based Localized Mobility Management) WG의 프로토콜을 이용하여 네트워크 기반의 고속 핸드오버 프로토콜을 제안하였다. NetLMM 프로토콜에서 핸드오버 지연을 개선하기 위해 IEEE 802.21 MIHS(Media Independent Handover Services)를 적용하였으며 Fluid Flow Mobility Model을 이용하여 제안하는 Fast NetLMM의 성능을 분석하였다. 분석 결과 Fast NetLMM 프로토콜은 다른 이동성 관리 프로토콜보다 향상된 성능을 보이는 것을 확인하였다.

• 대한임베디드공학회논문지
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• 제10권6호
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• pp.381-390
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• 2015

The efficient design of a transport protocol contributes to energy conservation as well as performance improvement in wireless sensor networks (WSNs). In this paper, a node-density-aware transport protocol (NDTP) for intra-cluster transmissions in WSNs for monitoring physical attributes is proposed, which takes node density into account to mitigate congestion in intra-cluster transmissions. In the proposed NDTP, the maximum active time and queue length of cluster heads are restricted to reduce energy consumption. This is mainly because cluster heads do more works and consume more energy than normal sensor nodes. According to the performance evaluation results, the proposed NDTP outperforms the conventional protocol remarkably in terms of network lifetime, congestion frequency, and packet error rate.

• Journal of Communications and Networks
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• 제14권6호
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• pp.703-709
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• 2012

In this paper, we propose a hybrid decode-amplify-forward incremental cooperative diversity protocol using SNR-based relay selection. In the proposed protocol, whenever destination unsuccessfully receives the source's signal, one of relays that exploit hybrid decode-amplify-forward technique is chosen to retransmit the signal. We derive approximate closed-form expressions of outage probability and average channel capacity. Monte-Carlo simulations are presented to verify the theoretical results and compare the performance of the proposed protocol with the direct transmission protocol and conventional incremental relaying protocols.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.57-58
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• 2006

Ad hoc MAC protocols using directional antennas can be used to improve the network capacity by improving spatial reuse. But, the directional MAC protocols have the problem of deafness and have a poor throughput performance. The dual-channel DMAC protocol has been proposed to mitigate deafness and improve spatial reuse. In this paper, we propose a dual-channel DMAC protocol using the omnidirectional antenna for an out-of-band tone and directional antennas for control/data channels. In the proposed MAC protocol, an omnidirectional out-of-band tone mitigates deafness and directional antennas used in control/data channels improve spatial reuse and reduce interference packets. The throughput performance of the proposed MAC protocol is confirmed by computer simulations using Qualnet ver. 3.8 simulator.