• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10c
• /
• pp.253-255
• /
• 2004

현재의 센서 네트워크를 구성하고 있는 센서 노드들은 배치 전에 미리 입력된 라우팅 및 감지 서비스만을 제공한다. 이러한 센서 네트워크 및 노드 구조는 기존의 고정화된 환경에는 적합하나 차세대 유비쿼터스 환경과 같이 시스템이 스스로 성장하며 서비스 추가 및 재설정 요구가 빈번하게 일어나는 환경에서는 그대로 적용하기가 힘들다. 따라서 본 논문에서는 유비쿼터스 환경에서 시스템 레벨의 정책 및 환경 변화에 따라 적응적으로 동작할 수 있는 센서 네트워크 노드 구조를 제안하여, 또한 제안된 구조에서 기존의 구조에 대한 에너지 소모 정도를 분석하여 제안의 현실성을 검증한다.

• The KIPS Transactions:PartC
• /
• v.13C no.2 s.105
• /
• pp.195-202
• /
• 2006

For applying sensor networking technology for our daily life, security service is essential, and pairwise key establishment is the key point for security. In this paper, we propose fairwise key establishment mechanism for secure coumunication in sensor networks. In the mechanism, we cluster the network field before deployment and predistribute key materials to normal sensor nodes and clusterheads. For clusterheads, more key materials are predistributed, and after deployment, sensor nodes which need to establish pairwise keys with other sensor nodes in different clusters make request for related key materials to their own clusterheads. Our proposal reduces the memory requirements for normal sensor nodes by distributing more information to clusterheads, and it raises the security level and resilience against node captures. In addition, it guarantees perfect pairwise key establishments for every pair of neighboring nodes and provides efficient and secure sensor communications.

• Journal of the Korea Society of Computer and Information
• /
• v.18 no.12
• /
• pp.27-34
• /
• 2013

In wireless sensor networks, sensors need to communicate with each other to send their sensing data to the administration node and so they are susceptible to many attacks like garbage packet injection that cannot be prevented by using traditional cryptographic approaches. A behavior-based detection is used to defend against such attacks in which some specialized monitoring nodes overhear the communications of their neighbors to detect bad packets. As monitoring nodes use more energy, it is desirable to use the minimal number of monitoring nodes to cover the whole or maximal part of the network. The monitoring nodes can either be selected among the deployed normal nodes or differ in type from normal nodes. In this study, we have developed an algorithm for selecting the predefined number of monitoring nodes needed to cover the maximum number of normal nodes when the different types of normal nodes and monitoring nodes are deployed. We also have investigated experimentally how the number of monitoring nodes and their transmission range affect the connection ratio of the monitoring nodes and the coverage of the normal nodes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.05a
• /
• pp.856-859
• /
• 2010

WSN is composed of a lot of small sensors with the limited hardware resources. In WSN, at the initial stage, sensor nodes are randomly deployed over the region of interest, and self-configure the clustered networks by grouping a bunch of sensor nodes and selecting a cluster header among them. Specially, in Mobile-WSN environment, in which the administrator's intervention is restricted, the self-configuration capability is essential to establish a power-conservative Mobile-WSN which provides broad sensing coverage and communication coverage. In this paper, we propose a self-configuration routing protocol for Mobile-WSN, which consists of step-wise novel protocols for initial deployment, effective joining and removal of sensor nodes, which result in reducing overall power consumption, and extending the lifetime of network.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.6
• /
• pp.51-57
• /
• 2009

Wireless sensor networks consist of numerous sensor nodes that have inexpensive and limited resources. Generally, most of the sensors are assigned to the hazardous or uncontrollable environments. If the sensor nodes are randomly assigned to the wide target area, it is very hard to see the accurate locations of sensor nodes. Therefore, this study provides an efficient key distribution scheme to solve these problems. Based on the provided scheme, the study enabled the closely neighboring nodes to exchange information with each other after securing safe links by using the pre-distributed keys. At the same time, the provided scheme could increase the probability of multiparty key detection among nodes by using the location information of sensor node. Lastly, the study intended to show the superiority of the limitation method through a performance test.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.14 no.4
• /
• pp.150-160
• /
• 2011

IT convergence and integration technology aims to create new synergies by combining IT related technology and performance. This study conducted a basic research for combining construction and IT technology to create new synergies. Specifically, the purpose of this study is to combine USN and GIS technology and then apply it to urban facilities management. For this, we have developed the USN hardware, tested propagation communications, and made the GIS Algorithm and a system. Existing sensor node allocation method is mostly to install in a random way or with in-situ survey, but the problem with this method is contradictory to cost effectiveness and efficiency. To solve this problem, we developed a new method for sensor allocation. Using this method, the USN technology could be applied in the range of city unit. This technology can be applied to the ubiquitous urban development such as U-City and Smart City.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.4C
• /
• pp.338-346
• /
• 2012

Wireless sensor network (WSN) technology provides a variety of medical and healthcare solutions to assist detection and communication of body conditions. However, data reliability inside WSN might be influenced to healthcare routing protocol due to limited hardware resources of computer, storage, and communication bandwidth. For this reason, we have conducted various wireless communication experiments between nodes using parameters such as RF strength, battery status, and deployment status to get a optimal performance of mobile healthcare routing protocol. This experiment may also extend the life time of the nodes. Performance analysis is done to obtain some important parameters in terms of distance and reception rate between the nodes. Our experiment results show optimal distance between nodes according to battery status and RF strength, or deployment status and RF strength. The packet reception rate according to deployment status and RF strength of nodes was also checked. Based on this performance evaluation, the optimized sensor node battery and deployment in the developed our mobile healthcare routing protocol were proposed.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2011.10a
• /
• pp.820-823
• /
• 2011

WSN is composed of a lot of small sensors with the limited hardware resources. In WSN, at the initial stage, sensor nodes are randomly deployed over the region of interest, and self-configure the clustered networks by grouping a bunch of sensor nodes and selecting a cluster header among them. In this paper, we propose a self-configuration routing protocol for WSN, which consists of step-wise ripple routing algorithm for initial deployment, effective joining of sensor nodes. RRA is search node in RF-coverage of each node, which result in fast network connection, reducing overall power consumption, and extending the lifetime of network.

• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10b
• /
• pp.415-417
• /
• 2004

수많은 경량의 센서 노드들이 무선통신으로 연결되어 사람이 접근하기 어려운 환경에서도 응용서비스를 수행하는 센서 네트？에 대한 관심이 고조되고 있다. 노드의 다량성과 사랑의 접근불가성으로 인해 센서 네트？은 무인 운용이 가능하도록 설계되고 배치되어야 하며 이를 위한 적응형 소프트웨어에 대한 연구가 활발히 진행되고 있는 추세이다 본 논문은 소프트웨어 아키텍쳐 기술 언어를 사용하여 노드 장애나 환경 변화에 동적으로 대처하여 스스로를 재구성하는 센서 네트？의 적응형 소프트웨어 설계를 제시한다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39B no.10
• /
• pp.708-714
• /
• 2014

Wireless sensor networks (WSNs) generally consist of densely deployed sensor nodes that depend on batteries for energy. Having a large number of densely deployed sensor nodes causes energy waste and high redundancy in sensor data transmissions. The problems of power limitation and high redundancy in sensing coverage can be solved by appropriate scheduling of node activity among sensor nodes. In this paper, we propose a cellular automata based node scheduling algorithm for prolonging network lifetime with a balance of energy savings among nodes while achieving high coverage quality. Based on a cellular automata framework, we propose a new mathematical model for the node scheduling algorithm. The proposed algorithm uses local interaction based on environmental state signaling for making scheduling decisions. We analyze the system behavior and derive steady states of the proposed system. Simulation results show that the proposed algorithm outperforms existing protocols by providing energy balance with significant energy savings while maintaining sensing coverage quality.