• Journal of Advanced Navigation Technology
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• v.15 no.1
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• pp.54-60
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• 2011

The development of wireless sensor networks (WSN) can be motivated by several types of applications. However, these applications demand an energy-efficient WSN that can prolong the network lifetime and can provide high throughput, low latency and delay. Designing wireless sensor networks with the capability of prolonging network lifetime catch the attention of many researchers in wireless system and network field. Contrasts with Mobile Ad Hoc Network system, Wireless Sensor Networks designs focused more on survivability of each node in the network instead of maximizing data throughput or minimizing end-to-end delay. In this paper, we will study part of data link layer in Open Systems Interconnection (OSI) model, called medium access control (MAC) layer. Since the MAC development of energy aware MAC Protocol for wireless sensor layer controls the physical radio part, it has a large impact on the overall energy consumption and the lifetime of a node. This paper proposes a analytical approach that tries to reduce idle energy consumption, and shows the increasement of network end-to-end arrival rate due to efficiency in energy consumption from time slot management.

• Journal of Industrial Technology
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• v.21 no.A
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• pp.59-64
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• 2001

This paper analyzes the performance of the several types of ACL(Asynchronous ConnectionLess) packets used in Bluetooth according to a BER(Bit Error Rate) and a packet length and proposes an optimal packet type and an optimal size of the packet being able to be used under the given BER. This paper proposes how to obtain the optimal packet type and the optimal size of the packet maximizing the performance measure under the given BER. In addition, this paper shows that the optimal type and size of the packet maximizing the throughput are different from those maximizing the mean transmission time. This occurs because the Bluetooth uses not only one type of packet but also various types of packets.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.4A
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• pp.451-463
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• 2000

In this paper, we design the radio data link protocols with QoS provisioning for mobile multimedia such as voice, data, and video in CDMA-based ATM networks, and analyze the performance of the data link protocols. To support mobile multimedia traffic, the required QoS parameters and the characteristics are analyzed, and wireless protocol stacks are proposed for integrating the wireless access network and ATM transport networks, and radio data link protocols are designed for provisioning QoS Control. The data link protocols are analyzed assuming that the system is supporting voice and data traffic simultaneously. In case of data traffic, the delay and throughput of SREJ ARQ and Type-1 Hybrid ARQ scheme are compared, and in case of voice traffic, the packet loss rate of BCH coding is analyzed according to the varying data traffic loads. The results indicate that the adaptive radio link protocols are efficient to support QoS requirements while the complexities are increased.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.7
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• pp.9-19
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• 2004

WLAN (Wireless Local Area Networks) needs error recovery and flow control schemes to support reliable multicast protocol. Limited wireless bandwidth, as well as queuing losses caused by the asymmetric wired/wireless interactions, demands more effective approaches for reducing packet losses. Moreover, since the wireless channel is a shared broadcast medium, if sender receives feedback information simultaneously from several receivers, the feedback delays data frame transmission of forward direction by introducing channel congestion and burden at the sender. Therefore, it is important to minimize the amount of feedback information from receivers. In this paper, we propose an ARS(Adaptive Redundancy Scheme) that combines FEC(Forward Error Correction) using channel state estimation and ARQ(Automatic Repeat Request) both to reduce the amount of feedback information and the number of retransmissions and to guarantee high data reliability in a WLAN multicast environment. Performance of the proposed scheme is evaluated by means of analysis and simulations in AWGN and Rayleigh fading channels. The results show that the proposed scheme reduces the amount of feedback information and the number of retransmissions and guarantees high data reliability, while keeping throughput efficiency similarly with the conventional FEC and ARQ scheme.

• Journal of electromagnetic engineering and science
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• v.12 no.3
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• pp.189-195
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• 2012

In this paper, we propose a novel protocol called a Multi-hop Diversity Transmission protocol in which the retransmission is realized by a relay that is Nearest to a current Source (MDTNS). We derive the mathematical expressions of the packet error rate (PER) and the average number of transmissions over Nakagami-m fading channels, and verify them by Monte Carlo simulations. The simulation results show that the MDTNS protocol improves the performance of the network in terms of PER when compared to the Multi-hop Diversity Transmission protocol in which the retransmission is done by a relay that is Nearest to Destination (MDTND) and to the conventional multi-hop transmission (CMT) protocol.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2013.10a
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• pp.984-987
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• 2013

In concept, such as the backup of wired network and disaster prevention network of water treatment measurement and control system, reliability and security of high level of sending and receiving data between the nodes must be ensured in Ad-hoc network construction. Rather than apply the common communication protocols of Ad-hoc network construction during the FA network of closed water treatment facility with the facility of a certain scale is concentrated contrast, and high characteristics of the water treatment system infrastructure, public facilities We have developed a specific protocol another that applies the OTP of communication frame of process control commands and H-ARQ with ZRP by applying the flexibility to time constraints such as precision industrial plants to ensure the safety and property of facility operation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12C
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• pp.1222-1230
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• 2005

We aim at increasing the throughput of the hybrid automatic retransmission request (HARQ) protocol in Space-Time (ST) coded multi-antenna transmission systems. By utilizing reliability information at the decoder, we obtain an improved probability of successful decoding, which enhances the overall system throughput at low-complexity. Simulations and analytical results demonstrate the performance of our scheme in impulse noise environment as well as AWGN and fading multi-input multi-ouput (MIMO) channels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.9B
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• pp.1616-1623
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• 1999

This paper describes error resilient coding scheme is added in WLL system and its application for robust low-bit rate still image transmission over power controlled W-CDA system Rayleigh fading channels. The baseline JPEG compressing methods are uses in image coding over wireless channel. The channel uses Reed-Solomon(RS) outer codes concatenated with convolutional inner codes, and truncated type I hybrid ARQ protocol based on the selective repeat strategy and the RS error detection capability. Simulation results are proved for the statistics of the frame-error bursts of the proposed system in comparison with conventional WLL system. it gains the 2 dB of the Eb/No in same BER.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.46 no.4
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• pp.61-68
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• 2009

In this paper, we propose a Cluster-based Cooperative Routing using ARQ (CCRA) for supporting both reliability and transmitting efficient service in mobile ad-hoc wireless sensor networks with Rayleigh fading environments. The main contributions and features of this paper are as follows. First, the clustering method which uses the position information of nodes as underlying structure for supporting reliable transmission services is used. Second, the cooperative data transmission method based on the underlying clustering informations is used to improve both reliability and data transmission efficiency. Third, the ARQ-based transmission is used to improve transmission reliability. Fourth, we consider a realistic approach, in the points of view of mobile ad-hoc wireless sensor networks, based on mobile sensor nodes as well as fixed sensor nodes in the sensor fields while the conventional research for sensor networks focus on mainly fixed sensor networks. The performance evaluation of proposed routing protocol implemented via simulation using Optimized Network Engineering Tool (OPNET) and theoretical analysis.

• Proceedings of the Korea Multimedia Society Conference
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• 2002.11b
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• pp.644-648
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• 2002

멀티미디어 서비스를 제공하는 미래의 이동통신 시스템에서는 데이터의 신뢰성 있는 전송을 위해 데이터링크 계층에서 제공하는 프레임 에러율(FER: Frame Error Rates)을 감소시켜야 한다. 이를 위해 라디오링크 프로토콜(RLP: radio link protocol) 계층에서는 ARQ(Automatic Repeat request) 기법을 사용한다. 본 논문에서는 기지국에서 이동 호스트로 전송되는 국부적인 재전송 프레임(Frame)의 순서가 연속된 에러로 인하여 순서가 뒤바뀌고, 이로 인하여 기지국 데이터 링크계층에서 잦은 재전송으로 발생되는 높은 상호지연을 줄이기 위해 개선된 비순서적 재전송 기법을 제안하였다. 제안된 기법은 재전송방법 중 선택적 거절(selective-reject) ARQ의 비순서적 재전송에 수정한 빠른 재전승 기법을 적용하였으며, 기지국과 이동호스트 사이에서 데이터그램(Datagram)의 단편화(fragment)로 인한 링크계층의 Re-Sequencing을 하지 않기 때문에, 종단간 지연된 성능을 향상 시킬 수 있다.