• 한국인터넷방송통신학회논문지
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• 제17권3호
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• pp.107-114
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• 2017

클러스트-트리 무선센서네트워크에서 비콘활성화 모드일 때 비콘 충돌은 아주 중요한 문제가 되고 있다. 본 논문에서는 비콘 충돌 현상을 회피하고 네트워크 확장성을 제공하기 위하여 멀티채널 시분할 스케줄링 기법을 제안한다. 코디네이터는 할당된 채널들과 타임슬롯들에 대한 정보를 포함하고 있는 비콘프레임을 방송하는 역할을 한다. 이를 통해 새로운 노드는 자신의 채널과 타임슬롯을 결정하게된다. 제안 방식의 성능을 전형적인 지그비 방식과 비교한다. 제안 방식은 클러스트 트리 무선센서네트워크상에서 비콘 충돌을 방지하고 네트워크 확장면에서 효과적으로 구성이 가능하게 한다.

• 한국멀티미디어학회논문지
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• 제20권4호
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• pp.640-648
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• 2017

Sensors have limited resources in sensor networks, so efficient use of energy is important. In order to use the energy of the sensor node efficiently, researches applying mobile sink to the sensor network have been actively carried out. The sink node moves the sensor network, collects data from each sensor node, which spread the energy concentrated around the sink node, thereby extending the entire life cycle of the network. But, when the sink node moves, it requires a reset of the data transmission path, which causes a lot of control messages and delays. In this paper, we propose a CMS(Cluster-based Mobile Sink) method to support the movement of mobile sink in a cluster sensor environment. The proposed scheme minimizes an amount of control messages without resetting the routing paths of entire sensor networks by supporting the sink mobility path using the neighbor cluster list. And, it simplifies the routing path setup process by setting a single hop path between clusters without a gateway. The experiment results show that the proposed scheme has superior energy efficiency in processing and network structure, compared with existing clustering and mesh routing protocols.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권11호
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• pp.4644-4661
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• 2015

Wireless sensor networks are often organized in the form of clusters leading to the new framework of WSN called cluster or hierarchical WSN where each cluster head is responsible for its own cluster and its members. These hierarchical WSN are prone to various routing layer attacks such as Black hole, Gray hole, Sybil, Wormhole, Flooding etc. These routing layer attacks try to spoof, falsify or drop the packets during the packet routing process. They may even flood the network with unwanted data packets. If one cluster head is captured and made malicious, the entire cluster member nodes beneath the cluster get affected. On the other hand if the cluster member nodes are malicious, due to the broadcast wireless communication between all the source nodes it can disrupt the entire cluster functions. Thereby a scheme which can detect both the malicious cluster member and cluster head is the current need. Abnormal energy consumption of nodes is used to identify the malicious activity. To serve this purpose a learning based energy prediction algorithm is proposed. Thus a two level energy prediction based intrusion detection scheme to detect the malicious cluster head and cluster member is proposed and simulations were carried out using NS2-Mannasim framework. Simulation results achieved good detection ratio and less false positive.

• 한국산업정보학회논문지
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• 제16권2호
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• pp.13-18
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• 2011

Security supports are a significant factor in mobile ad hoc networks. Especially in dynamic topologies, considering cluster, key management is essential to provide a secure system. Recently, Li-Liu proposed iD-based multiple key management scheme for cluster-based ad hoc networks. However, we found the security weakness of their scheme. In this paper, we analyze the security of Li-Liu's scheme and show that master secret key and fragment of the master secret key can be revealed to compromised CHs and nodes. Furthermore, we propose a solution to improve the scheme against disclosure of the share key and the master secret key even though system parameters are opened to compromised nodes and modify the Li-Liu's scheme fitted for a scalable networks. The improved IMKM scheme could be usefully applied in dynamic cluster-based MANETs such as the military battlefields, mobile marketplace and VANETs.

• 디지털융복합연구
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• 제11권5호
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• pp.279-284
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• 2013

본 논문에서는 무선 멀티미디어 센서 네트워크의 서비스 수명 보장을 위해 클러스터 기반의 새로운 라우팅 프로토콜을 제안한다. 제안된 프로토콜은 무선 센서 멀티미디어 컴퓨팅 환경에서 에너지 소모를 줄이고 서비스 오류를 줄이기 위해 인트라 클러스터 라우팅과 인터 클러스터 라우팅을 수행한다. 또한 제안된 클러스터 라우팅은 라우팅 신뢰성을 향상시키고, 패킷 손실을 최소화하며, 관리 오버헤드를 최소화하고, 에너지 소모를 최소화한다. 본 논문에서는 시뮬레이션 결과를 통해서 제안된 기법이 DSR (Dynamic Source Routing) 기법, AODV(Adhoc On-demand Distance Vector routing) 기법에 비해서 효율성이 우수함을 보인다.

• 한국정보전자통신기술학회논문지
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• 제8권5호
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• pp.405-411
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• 2015

본 논문에서 우리는 모바일 싱크노드를 가지는 모바일 센서 네트워크를 위한 경로배정 프로토콜을 제안합니다. 제안된 논문은 모바일 싱크를 도입하는 것에 의해 확장됩니다. 모바일 싱크는 그 주변의 클러스터 헤드로부터 센싱 데이터를 수집하는 가장 많은 멤버수를 가진 클러스터 헤드로 이동합니다. 이러한 이동은 싱크에 패킷을 보내는데 필요한 에너지소모를 감소시킵니다. 모의실험 결과는 제안된 프로토콜이 에너지 효율면에서 LEACH-ME를 능가하는 것을 보여줍니다.

• 센서학회지
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• 제19권5호
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• pp.342-348
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• 2010

The wireless sensor networks have been extensively researched. One of the issues in wireless sensor networks is a developing energy-efficient clustering protocol. Clustering algorithm provides an effective way to extend the lifetime of a wireless sensor networks. In this paper, we proposed an energy efficient clustering scheme by adjusting group size. In sensor network, the power consumption in data transmission between sensor nodes is strongly influenced by the distance of two nodes. And cluster size, that is the number of cluster member nodes, is also effected on energy consumption. Therefore we proposed the clustering scheme for high energy efficiency of entire sensor network by controlling cluster size according to the distance between cluster header and sink.

• 한국통신학회논문지
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• 제34권10B호
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• pp.964-972
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• 2009

무선 메쉬 네트워크(Wireless Mesh Network, WMN)는 다중 인터페이스와 다중 채널을 지원함으로써 기존의 무선 네트워크에서 발생되는 여러 문제점을 해결할 수 있는 핵심적인 미래기술로 대두되고 있다. WMN에서 다중 채널의 사용은 무선 네트워크 노드들이 사용하는 대역폭을 본질적으로 증가시켜준다. 그러나 이러한 대역폭을 충분히 사용하기 위해서는 다중 채널 환경에서 발생할 수 있는 채널 간 간섭을 최소화하는 채널 할당 기법이 요구된다. 본 논문에서는 WMN의 성능 향상을 위하여 클러스터링 기반의 최소 간섭 채널 할당(Minimum Interference Channel Assignment, MI-CA) 알고리즘을 제안한다. MI-CA 알고리즘은 클러스터 간의 Inter-Cluster 채널 할당과 클러스터 내부의 Intra-Cluster 채널 할당으로 구성된다. Inter-Cluster 채널 할당에서는 전체 WMN을 위한 베어본 채널을 MST(Minimum Spanning Tree) 기반으로 클러스터 헤더와 보더 노드에 할당하고, Intra-Cluster 채널 할당에서는 클러스터 멤버들 간에 직교채널을 재 할당함으로써 간섭을 최소화 한다. 시뮬레이션 결과 본 논문에서 제안한 MI-CA 알고리즘이 채널 간섭을 최소화함으로써 WMNs의 성능을 향상시킬 수 있음을 입증하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권8호
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• pp.2042-2060
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• 2013

In wireless sensor networks (WSNs), energy efficiency is one of the most essential design considerations, since sensor nodes are resource constrained. Group communication can reduce WSNs communication overhead by sending a message to multiple nodes in one packet. In this paper, in order to simultaneously resolve the transmission security and scalability in WSNs group communications, we propose a hierarchical cluster-based secure and scalable group key management scheme, called HRKT, based on logic key tree and route key tree structure. The HRKT scheme divides the group key into cluster head key and cluster key. The cluster head generates a route key tree according to the route topology of the cluster. This hierarchical key structure facilitates local secure communications taking advantage of the fact that the nodes at a contiguous place usually communicate with each other more frequently. In HRKT scheme, the key updates are confined in a cluster, so the cost of the key updates is reduced efficiently, especially in the case of massive membership changes. The security analysis shows that the HRKT scheme meets the requirements of group communication. In addition, performance simulation results also demonstrate its efficiency in terms of low storage and flexibility when membership changes massively.

• ETRI Journal
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• 제41권5호
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• pp.648-657
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• 2019

A cluster topology was proposed with the assumption of zero noise to improve the performance of wireless body area networks (WBANs). However, in WBANs, the transmission power should be reduced as low as possible to avoid the effect of electromagnetic waves on the human body and to extend the lifetime of a battery. Therefore, in this work, we consider a bit error rate for a cluster-based WBAN and analyze the performance of the system while the transmission of sensors and cluster headers (CHs) is controlled. Moreover, a hierarchical topology is proposed for the cluster-based WBAN to further improve the throughput of the system; this proposed system is called as the hierarchical cluster WBAN. The hierarchical cluster WBAN is combined with a transmission control scheme, that is, complete control, spatial reuse superframe, to increase the throughput. The proposed system is analyzed and evaluated based on several factors of the system model, such as signal-to-noise ratio, number of clusters, and number of sensors. The calculation result indicates that the proposed hierarchical cluster WBAN outperforms the cluster-based WBAN in all analyzed scenarios.