• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2019.05a
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• pp.304-305
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• 2019

Wireless sensor networks are used in various applications due to the flexibility of network. In particular, the energy harvesting wireless sensor network (EH-WSN) has been introduced to solve the power limitation problem, and the application range of the sensor network is further expanded. In order to transmit the sensed data to the destination node, the MAC protocol considering the power of the nodes has been studied. The power situation and the urgency of the data are important elements of data transmission, and a medium access control protocol that comprehensively considers data urgency and power of nodes is required. In this paper, we propose a medium access control protocol which can select relay nodes according to power situation and urgency of data.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1128-1134
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• 2007

Recently, sensor network technology is a highly concerned area due to the expectation of many applications in various fields. The application of sensor network technology to the marine and ocean surveillance and investigation makes the marine environmental research easier since intelligent sensor nodes substitute the human labor work. In ocean sensor network, the localization scheme for the sensor nodes is most essential because all the information without from sensor nodes might be useless unless the positional information of each sensor nodes is provided. In this paper, the localization scheme with mobile beacons in ocean sensor networks is suggested and showed it could be effective for applying to marine circumstances. Even though the previous localization scheme(Ssu's) has advantages that additional hardware is not required for obtaining the information of distance and angle and shows the high accuracy of location and energy efficiency and easy expandability as well, it has also demerits the location error increases as the minimum distance between the absolute positional information become closer. In our works, the improved localization scheme with the presumed area of sensor node using geometric constraints is suggested.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.49 no.8
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• pp.84-97
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• 2012

In wireless sensor networks, cluster structure brings on many advantages such as load balancing, energy saving, and distributed key management, and so on. To transform a physical network into the cluster structure, sensor nodes should invoke a cluster formation protocol. During the protocol operation, if some nodes are compromised and they do not conform to the protocol, an inconsistency of membership in a cluster happen. This splits the cluster and consequently increases the number of clusters and decreases the number of members in the cluster. In this paper, we propose a scheme which well copes with such a problem. First, our scheme generates two hop clusters where hop distance between any two nodes is at most two. Besides, our scheme employs verification of two hop distant nodes to prevent the cluster split induced by compromised nodes. Last, our scheme mainly employs broadcast transmissions to reduce energy consumption of nodes. Simulation results have proven that our scheme reduces the number of clusters and more secure and energy-efficient than other scheme.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.3B
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• pp.149-157
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• 2012

In WSN environment, the sensor nodes collect sensed data, and transmit data to the BS. BS is difficult to trust the data from unauthenticated nodes. Therefore, many papers have been proposed about the node authentication and the safety of data. In the AM-E paper, data is delivered after node authentication. In this time, the sensor nodes are directly communicated to BS the AREQ/AREP message for authentication. Therefore, the sensor nodes consume more energy for authentication. Also, noes communicate directly with the BS for authentication will have problem due to the limited energy of nodes. In this paper, the same security with AM-E is supported, Furthermore, to minimize the energy consumption, IDE based hierarchical node authentication protocol is proposed. Compared with AM-E, the number of alive nodes is increased about 39%. Thus, the entire network life time is extended and energy efficiency is improved.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.467-470
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• 2012

This paper proposes a technique of sybil attack detection using an ID-based certificate on sensor network. First, it can solve the broadcast storm problem happening when keys are distributed to sensor nodes. Second, it prevents the replay attack by periodically generating and changing the keys of sensor nodes with Key-chain technique. Third, it authenticates sensor node's ID using hash function. So, it maximizes sensor node's memory usage, reduces communication overhead. Finally it detects Sybil attack through ID-based certificate. Therefore, the proposed technique of Sybil attack detection using ID-based certificate consider simultaneously energy efficiency and stability on sensor network environment, and can trust the provided information through sensor network.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.1
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• pp.445-450
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• 2011

In this paper, we describe the implementation of an wireless sensor network testbed. We developed a web-based sensor network gateway and enhanced the Surge program which is used for sending and routing of packets in the sensor field. The developed program can transmit the source data of sensor nodes to the sink node via multi-hop routing, and deliver user commands to actuate sensor related equipments. Moreover, in this testbed, the data transport path from a node to the sink can be monitored. Thus we can approximate the network topology and the relative positions of sensor nodes. We also describe an application of the testbed that is used for controlling a remote robot.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.5
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• pp.1084-1090
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• 2015

In this paper, we propose a Tabu search algorithm to efficiently deploy the sensor nodes for maximizing the network sensing coverage in wireless sensor networks. As the number of the sensor nodes in wireless sensor networks increases, the amount of calculation for searching the solution would be too much increased. To obtain the best solution within a reasonable execution time in a high-density network, we propose a Tabu search algorithm to maximize the network sensing coverage. In order to search effectively, we propose some efficient neighborhood generating operations of the Tabu search algorithm. We evaluate those performances through some experiments in terms of the maximum network sensing coverage and the execution time of the proposed algorithm. The comparison results show that the proposed algorithm outperforms other existing algorithms.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.7B
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• pp.502-509
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• 2008

Wireless sensor networks consist of sensor nodes which are expected to be battery-powered and hard to replace or recharge. Thus, reducing the energy consumption of sensor nodes is an important design consideration in wireless sensor networks. For the implementation of energy-efficient MAC protocol, Sensor-MAC based on IEEE 802.11 protocol. In this paper, which has energy efficient scheduling, was proposed. In this paper, we propose Dynamic S-MAC that is dynamically operated by network-traffic states. Dynamic S-MAC protocol improves energy consumption of S-MAC due to change the frame length according to network-traffic states. Using NS-2 Simulation, we compare the performance of Dynamic S-MAC with S-MAC protocol.

• ETRI Journal
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• v.33 no.6
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• pp.857-863
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• 2011

Due to uncertainties in target motion and randomness of deployed sensor nodes, the problem of imbalance of energy consumption arises from sensor scheduling. This paper presents an energy-efficient adaptive sensor scheduling for a target monitoring algorithm in a local monitoring region of wireless sensor networks. Owing to excessive scheduling of an individual node, one node with a high value generated by a decision function is preferentially selected as a tasking node to balance the local energy consumption of a dynamic clustering, and the node with the highest value is chosen as the cluster head. Others with lower ones are in reserve. In addition, an optimization problem is derived to satisfy the problem of sensor scheduling subject to the joint detection probability for tasking sensors. Particles of the target in particle filter algorithm are resampled for a higher tracking accuracy. Simulation results show this algorithm can improve the required tracking accuracy, and nodes are efficiently scheduled. Hence, there is a 41.67% savings in energy consumption.

• Journal of Communications and Networks
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• v.15 no.2
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• pp.164-172
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• 2013

We consider the problem of secure and robust clustering for quantized target tracking in wireless sensor networks (WSN) where the observed system is assumed to evolve according to a probabilistic state space model. We propose a new method for jointly activating the best group of candidate sensors that participate in data aggregation, detecting the malicious sensors and estimating the target position. Firstly, we select the appropriate group in order to balance the energy dissipation and to provide the required data of the target in the WSN. This selection is also based on the transmission power between a sensor node and a cluster head. Secondly, we detect the malicious sensor nodes based on the information relevance of their measurements. Then, we estimate the target position using quantized variational filtering (QVF) algorithm. The selection of the candidate sensors group is based on multi-criteria function, which is computed by using the predicted target position provided by the QVF algorithm, while the malicious sensor nodes detection is based on Kullback-Leibler distance between the current target position distribution and the predicted sensor observation. The performance of the proposed method is validated by simulation results in target tracking for WSN.