• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권8호
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• pp.1770-1785
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• 2013

In this paper, a multi-hop transmission protocol based on parallel communication of secondary users (SUs) is proposed. The primary multi-hop network coexists with a set of SUs by cooperative spectrum sharing. The main optimization target of our protocol is the overall performance of the secondary system with the guarantee of the primary outage performance. The energy consumption of the primary system is reduced by the cooperation of SUs. The aim of the primary source is to communicate with the primary destination via a number of primary relays. SUs may serve as extra decode-and-forward relays for the primary network. When an SU acts as a relay for a primary user (PU), some other SUs that satisfy the condition for parallel communication are selected to simultaneously access the primary spectrum for secondary transmissions. For the proposed protocol, two opportunistic routing strategies are proposed, and a search algorithm to select the SUs for parallel communication is described. The throughput of the SUs and the PU is illustrated. Numerical results demonstrate that the average throughput of the SUs is greatly improved, and the end-to-end throughput of the PU is slightly increased in the proposed protocol when there are more than seven SUs.

• Journal of information and communication convergence engineering
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• 제10권4호
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• pp.365-371
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• 2012

In recent years, researchers have been attracted to clustering methods to improve communication and data transmission in a network. Compared with traditional wireless networks, wireless sensor networks are energy constrained and have lower data rates. The concept of implementing a clustering algorithm in an existing project on gateway relocation is being explored here. Low energy adaptive clustering hierarchy (LEACH) is applied to an existing study on relocating a gateway. The study is further improved by moving the gateway to a specific cluster based on the number or significance of the events detected. The protocol is improved so that each cluster head can communicate with a mobile gateway. The cluster heads are the only nodes that can communicate with the mobile gateway when it (the mobile gateway) is out of the cluster nodes' transmission range. Once the gateway is in range, the nodes will begin their transmission of real-time data. This alleviates the load of the nodes that would be located closest to the gateway if it were static.

• 정보통신설비학회논문지
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• 제8권4호
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• pp.216-222
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• 2009

This paper proposes an integrated mobile sink networks management system which can monitor and control various kinds of wireless lan access points, located in many different areas divided by their managing groups, from multi-vendors, and their operations in networks. The proposed system has the center-local interoperability structure cooperating with local-center servers which can perform the same operations as the central servers for wireless lan access points from multi-vendors and wireless lan centric management features. For this purpose, we propose a new way of data design, messaging policy, and hierarchical system structure such that we can achieve stable and consistent management methods for various wireless access points on distributed networks.

• 정보통신설비학회논문지
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• 제10권3호
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• pp.86-91
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• 2011

Wireless sensor network (WSN) is a distributed self-organizing network which contains a large number of tiny multi-functional sensor nodes. The network life time is an important issue in WSN because every sensor node has a constraint on electric supply. In this paper, an energy consumption model is described and a GA-based algorithm will be used to optimize the energy consumption by analyzing the working model of sensor nodes. The model will provide an effective reference of working pattern for WSN. This algorithm is evaluated through analysis and simulations.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2006년도 하계학술대회
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• pp.91-94
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• 2006

In this paper, we deployed the tunnel inspection and monitoring system by wireless sensor network. It is shown that the wireless sensor network which is composed of sensor, wireless communication module, and gateway system can be applied to tunnel monitoring system. Sensors included herein are acceleration transducers, fire-alarm sensors, water-level sensors, and magnetic contact sensors. It is also found that the wireless sensor network can deliver sensing data reliably by ad-hoc networking technology. The gateway system that can send the sensing data to server by CDMA (code division multiple access) is developed. Finally, monitoring system is constructed by web service technology, and it is observed that this system can monitor the present state of tunnel without difficulties. Furthermore, the above system provides an alternative to inspect and monitor the tunnel efficiently where the conventional wired system cannot be applied.

• 정보통신설비학회논문지
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• 제9권3호
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• pp.86-91
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• 2010

In this paper, we introduce UFSN (Underground Facility Sensor Network) in order to build the intelligent management system for the underground facility and drainage in convergence with ubiquitous technologies. and propose the three type of UFSN.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2006년도 하계학술대회
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• pp.47-52
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• 2006

In this paper, we suggested new network architecture to provide seamless service between the cellular system and new wireless broadband network such as IEEE 802.16e, called WiBro. The interworking technologies are very important issue because mobile operator should provide service connectivity between various wireless networks based on different access technologies. Moreover a change and modification on legacy network should be minimized for providing interworking with new wireless broad-band network. We implemented proposed interworking architecture between 3G cellular network and 802.16e network to provide seamless service including interworking unit in real test environment. Also, we performed performance evaluation in hybrid network environments.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집B
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• pp.82-86
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• 2001

This papers deals with feasibility study of wireless motion control. Wireless telecommunication advances with development of IT technology and extends more and more areas. So we selected Bluetooth out of the technologies(Bluetooth, SWAP(SharedWireless Access Protocol), IrDA(Infra Red Data Association), WLAN(Wireless Local Area Network)) which was developed for local data communication and set up simple experimental system for wireless data transfer and server and client program for wireless data transfer was wrote. We successfully transferred some data wirelessly with this program.

• Journal of Information Processing Systems
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• 제7권1호
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• pp.17-28
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• 2011

Despite the fact that the deployment of sensor networks and target tracking could both be managed by taking full advantage of Voronoi diagrams, very little few have been made in this regard. In this paper, we designed an optimized barrier coverage and an energy-efficient clustering algorithm for forming Vonoroi-based Wireless Sensor Networks(WSN) in which we proposed a mobile target tracking scheme (CTT&MAV) that takes full advantage of Voronoi-diagram boundary to improve detectability. Simulations verified that CTT&MAV outperforms random walk, random waypoint, random direction and Gauss-Markov in terms of both the average hop distance that the mobile target moved before being detected and lower sensor death rate. Moreover, we demonstrate that our results are robust as realistic sensing models and also validate our observations through extensive simulations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 D
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• pp.3043-3045
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• 2005

기업체나 연구소와 같은 전자기자재의 사용이 많은 곳에서 효율적인 기자재 관리는 필수적이다. 이에 따라 모든 기자재를 관리하는 데이터베이스의 필요성이 대두된다. 본 논문은 데이터베이스를 카운터가 내장된 기자재로부터 추가적인 망의 포설 없이 기존의 전력선을 이용하여 음성통신과 초고속 통신이 가능한 전력선 통신(PLC:Power Line Communications)[1]를 통해 데이터베이스를 수집하고 수집된 데이터베이스를 무선으로 모니터링 할 수 있는 시스템을 구현하는데 그 목적이 있다. 이 시스템의 구현을 위해 ARM9 core를 기반으로 한 임베디드 리눅스 시스템에 웹서버, 무선프로토콜 등을 포팅하여 무선네트워크가 가능한 PDA, 노트북 등을 이용하여 손쉽게 모니터링 할 수 있는 시스템을 구현하고자 했다.