• Title/Summary/Keyword: 멀티홉 무선네트워크

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Studying Route Optimality in Multi-Hop Wireless Mesh Networks (다중 홉 무선 메쉬 네트워크에서 최적 경로에 관한 연구)

  • Kim, Seong-Kwan;Lee, Ok-Hwan;Lee, Sung-Ju;Choi, Sung-Hyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.1B
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    • pp.16-23
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    • 2009
  • This paper investigates how many optimal routes can be established in terms of a given wireless mesh routing metric. Although many of routing metrics have been devised to precisely derive the wireless link quality in mesh, most (if not all) metrics have not been evaluated their optimality along with routing protocols. We consider stateof-the-art routing metrics and a widely accepted routing protocol in order to observe the optimality of established routes varying the number of source nodes. Also, we propose a unidirectional routing to deal with possible link asymmetry feature in wireless links. Through comparative simulation evaluations, we show that the portion of optimally established routes becomes less as the network traffic load increases, regardless of employed metrics, network topologies, and routing protocols.

An Energy Balanced Multi-Hop Routing Mechanism considering Link Error Rate in Wireless Sensor Networks (무선 센서 네트워크의 링크 에러율을 고려한 에너지소모가 균등한 멀티 홉 라우팅 기법)

  • Lee, Hyun-Seok;Heo, Jeong-Seok
    • Journal of the Korea Society of Computer and Information
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    • v.18 no.6
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    • pp.29-36
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    • 2013
  • In wireless sensor networks, energy is the most important consideration because the lifetime of the sensor node is limited by battery. Most of the existing energy efficient routing protocols use the minimum energy path to minimize energy consumption, which causes an unbalanced distribution of residual energy among nodes. As a result, the power of nodes on energy efficient paths is quickly depletes resulting in inactive. To solve these problems, a method to equalize the energy consumption of the nodes has been proposed, but do not consider the link error rate in the wireless environment. In this paper, we propose a uniform energy consumption of cluster-based multi-hop routing mechanism considering the residual energy and the link error rate. This mechanism reduces energy consumption caused by unnecessary retransmissions and distributes traffic evenly over the network because considering the link error rate. The simulation results compared to other mechanisms, the proposed mechanism is energy-efficient by reducing the number of retransmissions and activation time of all nodes involved in the network has been extended by using the energy balanced path.

Adjusting Cluster Size for Alleviating Network Lifetime in Wireless Sensor Network (무선 센서네트워크에서 네트워크 수명 연장을 위한 클러스터 크기 조정 알고리즘)

  • Kwak, Tae-Kil;Jin, Kyo-Hong
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.6
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    • pp.1201-1206
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    • 2007
  • In this paper, we propose an algorithm that improve network lifetime by adjusting cluster size according to location information of sensor node in wireless sensor network (WSN) using clustering algorithm. The collected sensing information by sensor nodes in each cluster are transferred to sink node using inter-cluster communications method. Cluster head (CH) that located nearby sink node spend much more energy than those of far from sink node, because nearer CH forwards more data, so network lifetime has a tendency to decrease. Proposed algorithm minimizes energy consumption in adjacent cluster to sink node by decreasing cluster size, and improve CH lifetime by distributing transmission paths. As a result of mathematical analysis, the proposed algorithm shows longer network lifetime in WSN.

Multi-hop Relay System for Multicast and Broadcast Service over Mobile WiMAX (멀티캐스트와 브로드캐스트 서비스의 성능 향상을 위한 모바일 와이맥스 중계 시스템)

  • Cho, Chi-Hyun;Youn, Hee-Yong
    • Journal of KIISE:Information Networking
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    • v.35 no.3
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    • pp.227-234
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    • 2008
  • The development of wireless network technology allows high data rate seamless communication irrespective of the place and time in various emerging mobile service environment. Unlike wired networks, however, wireless networks utilize expensive limited bandwidth. MBS(Multicast Broadcast Service), which is supported by mobile WiMAX system based on IEEE802.16e, overcomes this problem using a shared downlink channel for efficiently supporting a number of users. However. the coverage and throughput of the system are significantly affected by the channel condition. In this paper we propose on MBS system employing Mobile Multi-Hop Relay(MMR) and adaptive modulation and coding(AMC) scheme. The result of NS-2 computer simulation shows that the throughput and transmission time are substantially improved by the proposed approach compared to the existing MBS system.

Performance Analysis of 1-2-1 Cooperative Protocol in Wireless Sensor Networks (무선 센서 네트워크에서 1-2-1 협력 프로토콜에 관한 연구)

  • Choi, Dae-Kyu;Kong, Hyung-Yun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.8 no.5
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    • pp.113-119
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    • 2008
  • Conventional 1-1-1 cooperative protocol offers path-loss gain as advantage of multi-hop and spatial diversity which is equivalent to MIMO system. This protocol is enable to get higher reliability and reduction of power consumption than those of the single-hop or multi-hop. But the 1-1-1 cooperative protocol get only the diversity order 2 and limited path-loss reduction gain because this protocol has a single cooperative relay. We propose 1-2-1 cooperative protocol using two cooperative relays R1, R2. The 1-2-1 cooperative protocol can improve path-loss reduction and increase diversity order 3. Moreover, the cooperative relay R2 attains diversity order 2. The signaling method in transmission uses DF (Decode and Forward) or DR (Decode and Reencode) and 1-2-1 DF/DR cooperative protocol are applied to clustering based wireless sensor networks (WSNs). Simulations are performed to evaluate the performance of the protocols under Rayleigh fading channel plus AWGN (Additive White Gaussian Noise).

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Cross-layer Design and its Performance Evaluation of Joint Routing and Scheduling for Maximizing Network Capacity of Wireless Mesh Networks (무선 메쉬 네트워크의 최대 전송 성능을 위한 라우팅과 스케쥴링의 계층 교차적 설계 및 성능 분석)

  • Min, Seokhong;Kim, Byungchul;Lee, Jaeyong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.12
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    • pp.30-45
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    • 2014
  • Recently, multimedia application users who demand for ubiquitous computing environment are rapidly increasing, and wireless mesh network is receiving attention as a cost-effective key technology for next generation wireless networking. When multiple flows are transmitting data at the same time in the network, routing for path selection of each flow and link resource allocation for data transmission of each flow are one of the key factors that influence to the effectiveness of the network directly. In this paper, we consider problems for path discovery and resource allocation of links at the same time and we propose an algorithm based on mathematical modeling using a technique for cross-layer optimization design in STDMA-based wireless mesh networks that can enhance transfer performance for each flow. We show by performance analysis that the proposed algorithm can enhance the throughput performance by maximally utilizing given bandwidth resources when the number of flows increase in multi-hop wireless mesh networks.

A Joint Wakeup Scheduling and MAC Protocol for Energy Efficient Data Forwarding in Wireless Sensor Networks (무선 센서 네트워크에서 에너지 효율적인 데이터 전송을 위한 스케줄링/ MAC 통합 프로토콜)

  • Cho, Jae-Kyu;Kwon, Tae-Kyoung;Choi, Yang-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.4B
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    • pp.207-214
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    • 2008
  • Under future internet environment, wireless sensor networks will be used in a wide range of applications. A major problem for designing sensor protocol is developing the most energy efficient technique to monitor an area of interest for a long time since sensors have some constraints such as small and a limited energy level. In addition, data latency is often a critical issue since sensory data is transmitted via multi hop fashion and need to be delivered timely for taking an appropriate action. Our motivation for designing a data forwarding protocol is to minimize energy consumption while keeping data latency bound in wireless sensor networks. In this paper, we propose a data forwarding protocol that consists of wakeup scheduling and MAC protocols, the latter of which is designed to achieve load balancing. Simulation results show that the proposed framework provides more energy-efficient delivery than other protocol.

Design and Implementation of Cluster based Routing Protocol using Representative Path in Ubiquitous Sensor Network (무선 센서네트워크에서 대표경로를 이용한 클러스터기반 라우팅 프로토콜의 설계 및 구현)

  • Jang, You-Jin;Kim, Ah-Reum;Chang, Jae-Woo
    • The Journal of the Korea Contents Association
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    • v.10 no.6
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    • pp.91-105
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    • 2010
  • A wireless sensor network communication technique has been broadly studied with continuous advances in ubiquitous computing environment. Especially, because the resource of the sensor node is limited, it is important to reduce the communication energy by using an energy-efficient routing protocol. The existing cluster-based routing protocols have a problem that they cannot select a cluster head efficiently by randomly choosing a head. In addition, because the existing cluster-based routing protocols do not support the large scale of network, they cannot be used for various applications. To solve the above problems, we, in this paper, propose a new cluster-based routing protocol using representative paths. The proposed protocol constructs an efficient cluster with distributed cluster heads by creating representative paths based on hop count. In addition, a new routing protocol supports multi-hop routing for data communication between a cluster member node and a cluster head as well as between cluster heads. Finally, we show that our protocol outperforms LEACH and Multihop-LEACH in terms of reliability and scalability.

Efficient Packet Transmission Mechanism for Multi-hop Wireless Sensor Networks (멀티-홉 무선 센서 네트워크에서 효율적인 패킷 전송 메커니즘)

  • Jeon, Jun Heon;Kim, Seong Cheol
    • 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.

Design and Implementation of Beacon based Wireless Sensor Network for Realtime Safety Monitoring in Subway Stations (지하철 역사에서 실시간 안전 모니터링 위한 비컨 기반의 무선 센서 네트워크 설계 및 구현)

  • Kim, Young-Duk;Kang, Won-Seok;An, Jin-Ung;Lee, Dong-Ha;Yu, Jae-Hwang
    • Journal of the Korean Society for Railway
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    • v.11 no.4
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    • pp.364-370
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    • 2008
  • In this paper, we proposed new sensor network architecture with autonomous robots based on beacon mode and implemented real time monitoring system in real test-bed environment. The proposed scheme offers beacon based real-time scheduling for reliable association process with parent nodes and dynamically assigns network address by using NAA (Next Address Assignment) mechanism. For the large scale multi-sensor processing, our real-time monitoring system accomplished the intelligent database processing, which can generate not only the alert messages to the civilians but also process various sensing data such as fire, air, temperature and etc. Moreover, we also developed mobile robot which can support network mobility. Though the performance evaluation by using real test-bed system, we illustrate that our proposed system demonstrates promising performance for emergence monitoring systems.