• Proceedings of the Korean Society of Computer Information Conference
• /
• 2019.07a
• /
• pp.99-100
• /
• 2019

무선 센서 네트워크(Wireless Sensor Network, WSN)에서의 싱크 이동은 전력 문제와 관련하여 해결해야할 중요한 문제이다. 또한 고정된 싱크를 사용하면 노드의 과도한 에너지 소비로 인해 네트워크 성능이 저하될 수 있는 문제점이 있다. 본 논문에서는 센서 노드의 클러스터가 퍼지 로직(Fuzzy Logic)을 기반으로 형성되고 싱크 재배치가 동적 2단계 메커니즘을 사용하여 결정되는 에너지 효율적인 싱크 재배치 기법을 제안한다. 본 논문에서 제안하는 기법은 싱크 재배치에 필요한 통신 오버 헤드를 최소화하고 데이터 패킷의 손실이나 지연을 최소화하여 싱크 재배치를 허용한다. 시뮬레이션 결과 제안 기법이 기존의 WSN의 대표적인 싱크 재배치 기법보다 네트워크 수명과 처리량 측면에서 우수하다는 것을 확인할 수 있었다.

• Journal of the Korea Society of Computer and Information
• /
• v.14 no.3
• /
• pp.113-119
• /
• 2009

In this paper, we proposed an efficient TDMA scheduling algorithm for a clustered Wireless Sensor Network. Since some previous algorithms used unnecessary idle period and schedule period in each frame. It became an overhead that might consume unexpected energy and delay data transmission. To solve this problem, a dynamic scheduling algorithm according to the number of member nodes and node traffic load within a cluster was suggested. Our proposed DS-MAC(Dynamic Scheduling MAC) could save energy and reduce transmission delay Then DS-MAC was analyzed mathematically to compare with the previous algorithms.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2010.10a
• /
• pp.386-388
• /
• 2010

에드 혹 네트워크(Ad hoc network)의 각 노드는 베터리 기반의 한정된 베터리로 동작하기 때문에 에너지 효율을 높이기 위한 다양한 라우팅 알고리즘이 연구되고 있다. 에드 혹 네트워크는 많은 수의 노드들이 거리 등의 상호 속성정보에 의한 노드의 관리기법에 따라 노드의 에너지를 관리해야 한다. 또한 주어진 망에서 관리 노드 또는 중계 노드 등이 동작 불가능한 상태가 되었을 경우 라우팅 경로가 끊어짐으로서 통신이 불가능한 상태가 되는 문제점이 있다. 본 논문에서는 트리망에서 중계 노드로 사용되는 클러스터 헤드 노드가 동작 불가능 상태가 되었을 경우, 노드간 거리 정보를 바탕으로 새로운 헤드 노드를 선출하는 ECDC(Energy Conservation Distance Control) 알고리즘을 제안하였다. 특히 제안된 ECDC 알고리즘을 이용함으로 노드에 대한 라이프타임을 향상 시키고 전체 라우팅 경로가 오랜 시간 동안 지속되는 결과를 보여주었다.

• Annual Conference of KIPS
• /
• 2012.04a
• /
• pp.612-614
• /
• 2012

센서 네트워크는 센싱 기능과 데이터 처리 그리고 무선 통신기능을 갖춘 많은 노드로 이루어져 있다. 센서 노드는 제한적인 CPU, 배터리 그리고 저장공간과 같은 제약사항을 가지고 있기 때문에 시간이 지날수록 노드의 수명이 다해 전체 적인 네트워크의 성능은 감소하게 된다. 본 논문에서는 이기종 센서 네트워크에서 노드 개수에 따른 작업 수행 시간의 분석을 통해 센서 네트워크의 수명을 판단한다. 성능 평가 결과 계층 기반의 라우팅 기법의 경우 클러스터 수의 비율이 네트워크의 수명에 큰 영향올 주는 것을 알 수 있다.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.6C
• /
• pp.544-561
• /
• 2002

In this paper, we propose a new hybrid type of the routing protocol (Virtual Cluster-based Routing Protocol: VCRP) for mobile ad-hoc networks, based on a virtual cluster, which is defined as a narrow-sense network to exchange the basic information related to the routing among the adjacent nodes. This particular approach combines advantage of proactive routing protocol (PRP), which immediately provides the route collecting the network-wide topological and metric information, with that of reactive routing protocol, which relies on the route query packet to collect the route information on its way to the destination without exchanging any information between nodes. Furthermore, it also provides the back-up route as a byproduct, along with the optimal route, which leads to the VCBRP (Virtual Cluster-based Routing Protocol with Backup Route) establishing the alternative route immediately after a network topology is changed due to degradation of link quality and terminal mobility, Our simulation studies have shown that the proposed routing protocols are robust against dynamics of network topology while improving the performances of packet transfer delay, link failure ratio, and throughput over those of the existing routing protocols without much compromising the control overhead efficiency.

• Journal of Digital Convergence
• /
• v.12 no.8
• /
• pp.219-227
• /
• 2014

Ethernet, ATM, and CAN are wide-utilized communication protocols for information transfer by internet. Many researches about Network Time-delay have been based on network modeling. But almost of them have not shown an optimal solution in various communication environments. So, asynchronous sample system modeling based internet is needed to be robust in various network environments. Also as closed loop system in internet has a different operational characteristics and noise characteristics comparing with conventional control system, new robust control method is needed in instruments which demand to be safe and precise for internet environments. In order to achieve the safe and precise real-time control in remote plant, this paper is aimed to analysis the transfer characteristics and time-delay of control system in cluster web server.

• The KIPS Transactions:PartC
• /
• v.16C no.2
• /
• pp.143-150
• /
• 2009

In trust-based networks, it is very important how to decide a node is trustworthy when one node performs communications with other node. In current networks based on trust, a node creates a new trust value from observation and then establishes an intercommunication path through the process of evaluating a targeted communication node. In our paper, we propose four trust models in which a new node enters a cluster and finds a target node to create a communication in ad-hoc networks. The proposed models have been classified according to the existence of reputation server and the trust evaluation functions. Through the proposed model, we found that new node finds target node more quickly in which there exists a reputation server in the cluster and considers neighbor node's recommendation as well as own experience information when calculates trust values. As our performance analysis, we focus the communication delay time to generate a final trust value for each trust model.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.11 no.9
• /
• pp.3472-3480
• /
• 2010

The Clustering technology of Energy efficiency wireless sensor network gets the energy efficiency by reducing the number of communication between sensor nodes and sink node. In this paper, First analyzed on the clustering technique of the distributed clustering protocol routing scheme LEACH (Low Energy Adaptive Clustering Hierarchy) and HEED (Hybrid, Energy-Efficient Distributed Clustering Approach), and based on this, new energy-efficient clustering technique is proposed for the cause the maximum delay of dead nodes and to increase the lifetime of the network. In the proposed method, the cluster head is elect the optimal efficiency node based on the residual energy information of each member node and located information between sink node and cluster node, and elected a node in the cluster head since the data transfer process from the data been sent to the sink node to form a network by sending the energy consumption of individual nodes evenly to increase the network's entire life is the purpose of this study. To verify the performance of the proposed method through simulation and compared with existing clustering techniques. As a result, compared to the existing method of the network life cycle is approximately 5-10% improvement could be confirmed.

• The KIPS Transactions:PartC
• /
• v.14C no.6
• /
• pp.519-524
• /
• 2007

One of the most important issues on the sensor network with resource limited sensor nodes is prolonging the network lifetime by effectively utilizing the limited node energy. The most representative mechanism to achieve a long lived sensor network is the clustering mechanism which can be further classified into the single hop mode and the multi hop mode. The single hop mode requires that all sensor nodes in a cluster communicate directly with the cluster head(CH) via single hop md, in the multi hop mode, sensor nodes communicate with the CH with the help of other Intermediate nodes. One of the most critical factors that impact on the performance of the existing multi hop clustering mechanism is the cluster size and, without the assumption on the uniform node distribution, finding out the best cluster size is intractable. Since sensor nodes in a real sensor network are distributed non uniformly, the fixed size mechanism may not work best for real sensor networks. Therefore, in this paper, we propose a new dynamic size multi hop clustering mechanism in which the cluster size is determined according to the distance from the sink to relieve the traffic passing through the CHs near the sink. We show that our proposed scheme outperforms the existing fixed size clustering mechanisms by carrying out numerical analysis and simulations.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.42 no.9 s.339
• /
• pp.29-40
• /
• 2005

In this paper, we propose a Cluster-based Multicast Routing (CMR) suitable for mobile ad-hoc networks. The main features that our proposed method introduces are the following: a) mobility-based clustering and group based hierarchical structure in order to effectively support stability and scalability, b) group based mesh structure and forwarding tree concepts in order to support the robustness of the mesh topologies which provides limited redundancy and the efficiency of tree forwarding simultaneously, and c) combination of proactive and reactive concepts which provide low route acquisition delay and low overhead. The performance evaluation of the proposed protocol is achieved via modeling and simulation. The corresponding results demonstrate the Proposed multicast protocol's efficiency in terms of packet delivery ratio, scalability, control overhead, end-to-end delay, as a function of mobility, multicast group size, and number of senders.