• Journal of electromagnetic engineering and science
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• v.12 no.2
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• pp.142-147
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• 2012

In this paper, we propose a novel protocol called Cooperative Multi-hop transmission using Incremental Relaying (CMIR). We evaluate the performance of the CMIR protocol by deriving expressions for the average end-to-end outage probability and the average number of transmissions. Monte Carlo simulations are presented to verify the accuracy of the theoretical analyses.

• Convergence Security Journal
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• v.15 no.3_1
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• pp.75-82
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• 2015

Recently, lot of researches on multi-level protocol have been done to balance the sensor node energy consumption of WSN and to improve the node efficiency to extend the life of the entire network. Especially in multi-hop protocol, a variety of models have been studied to improve energy efficiency and apply it in real system. In multi-hop protocol, we assume that energy consumption can be adjusted based on the distance between the sensor nodes. However, according to the physical property of the actual WSN, it's hard to establish this. In this paper, we propose low-power sub-cluster protocol to improve the energy efficiency based on the spread of distance. Compared with the previous protocols, the proposed protocol is energy efficient and can be effectively used in the wireless sensing network.

• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.131-140
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• 2011

Smart packet agent is an application that is proposed to provide routing protocol and service module in ubiquitous network environment. However, it uses multi-hop broadcast, thus it causes increasing network traffic, low-speed data transmission, and the unnecessary joining nodes. In this paper, a transmit technique that uses unicast-based multi-hop to have lower network traffic and faster transmission time than the multi-hop broadcast technique. In our scheme, u-Zone Master establishes temporary routing paths by calculating moving nodes' hop-counter. Therefore, it reduces smart packet agent's network traffic and retransmission rate. Besides, this paper proposed an UDP transmission that bases on sliding window. Hence, the Stop & Wait transmission speed is improved. The results, which are taken by analyzing performance prove that the proposed scheme has better performance.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.10
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• pp.29-34
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• 2011

We present a network coding scheme which is designed for improving throughput in multi-hop wireless network with multi-radio multi-channel. The co-channel interference and unreliability of wireless transmissions cause the wireless network to reduce throughput. In wireless network, multi-radio multi-channel technology shows benefit to cut down channel interferences and contentions. And network coding can reduce the complexity of scheduling and improve throughput by increasing usage of links in wireless network. In this paper, we propose a method of channel assignment and transmission scheduling in intra-session network coding that efficiently improve throughput for multi-hop wireless network by using mathematical modeling and linear programming. Moreover, we evaluate the performance of the intra-session network coding scheme by using AMPL with CPLEX. The simulation results show that intra-session network coding can achieve better throughput than traditional routing.

• Journal of Korea Multimedia Society
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• v.18 no.4
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• pp.492-498
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• 2015

In general, data packets from sensor nodes are transferred to the sink node in a wireless sensor networks. So many data packets are gathered around the sink node, resulting in significant packet collision and delay. In this paper, we propose an efficient packet transmission mechanism for multi-hop wireless sensor networks. The proposed mechanism is composed of two modes. One mode works between sink node and 1-hop nodes from sink. In this mode, data packets are transmitted in predefined time slots to reduce collisions. The other mode works between other nodes except sink node. In this mode, duplicated packets from neighbor nodes can be detected and dropped using some control signals. Our numerical analysis and simulation results show that our mechanism outperforms X-MAC and RI-MAC in terms of energy consumption and transmission delay.

• The Journal of the Acoustical Society of Korea
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• v.30 no.2
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• pp.86-91
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• 2011

In the underwater communications, the acoustic channel is in poor communication conditions, such as long propagation delay, narrow bandwidth, and high bit-error rate. For these bad acoustic channels, we propose an efficient automatic repeat request (ARQ) for multi-hop underwater network by using the concepts of concurrent bi-directional transmission, multiple sub-packets, and overhearing data packet instead of the acknowledgement signal. Our results show that the proposed ARQ significantly reduces the transmission latency especially in high BER compared with the existing Stop and Wait ARQ.

• Proceedings of the Korean Information Science Society Conference
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• 2010.11a
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• pp.99-100
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• 2010

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.1058-1060
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• 2007

기존 무선 네트워크의 전송 거리 및 전송률의 단점을 극복하기 위한 방법으로 멀티 홉 네트워크에 대한 연구가 활발히 이루어지고 있다. 하지만 멀티 홉 네트워크 연구의 초점이 라우팅 프로토콜에 편중되어 있어 정작 ARQ와 같은 데이터 전송의 효율과 신뢰성에 영향을 미치는 부분의 연구는 미흡한 실정이다. 따라서 본 논문에서는 멀티 홉 환경에서의 가능한 2가지 ARQ 방식인 End-to-End ARQ와 Hop-by-Hop ARQ의 환경 및 거리에 따른 성능을 시뮬레이션을 통해 비교 분석하여 멀티 홉 환경에 적절한 ARQ 방법을 찾고자 한다. 성능 분석 결과 모든 경우에 대해서 Hop-by-Hop ARQ가 더 좋은 성능을 보임을 확인하였다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.7B
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• pp.1098-1104
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• 2010

Recently, a variety of research of multi-hop routing protocol have been done to balance the sensor node energy consumption of WSN(wireless sensor network) and to improve the node efficiency for extending the life of the entire network. Especially in multi-hop protocol, a variety of models have been concerned to improve energy efficiency and apply in the reality. In multi-hop protocol, we assumption that energy consumption can be adjusted based on the distance between the sensor nodes. However, according to the physical property of the actual WSN, it's hard to establish this assumption. In this dissertation, we propose low-power sub-cluster protocol to improve the energy efficiency based on the spread of distance. Compared with the previous protocols, this proposed protocol can be effectively used in the wireless sensing networks.

• Journal of Digital Contents Society
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• v.8 no.3
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• pp.323-328
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• 2007

Communication systems beyond 3G should provide more than 100 Mbps for wireless access. In addition to smart antennas, wireless multi-hop networks are proposed to increase the cell size and throughput. For example, Zigbee technology is expected to provide low cost and low power connectivity and can be implemented in wireless mesh networks larger than is possible with Bluetooth. Also, home embedded system using wireless mesh network is one of the key market areas for Zigbee applications. If the line-of-sight path is shadowed by home obstacles, a direct connection between the access point (AP) and the node is not possible at high frequencies. Therefore, by using multi-hop relay scheme the end node can be reached to AP. In this paper, the relaying of data between the AP and the end node is investigated and the throughput and PER(Packet Error Rate) are evaluated in multi-hop wireless mesh networks by using DSSS/BPSK system.