• Journal of Information Processing Systems
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• v.6 no.2
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• pp.147-162
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• 2010

In this paper, we present a fine-grained localization algorithm for wireless sensor networks using a mobile beacon node. The algorithm is based on distance measurement using RSSI. The beacon node is equipped with a GPS sender and RF (radio frequency) transmitter. Each stationary sensor node is equipped with a RF. The beacon node periodically broadcasts its location information, and stationary sensor nodes perceive their positions as beacon points. A sensor node's location is computed by measuring the distance to the beacon point using RSSI. Our proposed localization scheme is evaluated using OPNET 8.1 and compared with Ssu's and Yu's localization schemes. The results show that our localization scheme outperforms the other two schemes in terms of energy efficiency (overhead) and accuracy.

• International Journal of Computer Science & Network Security
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• v.22 no.4
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• pp.358-366
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• 2022

Wireless sensor networks (WSN) are becoming widely used in collecting and sensing information in different fields such as in the medical area, smart phone industry and military environment. The main concern here is reducing the power consumption because it effects in the lifetime of wireless sensor during commutation because it may be work in some environment like sensor in the battlefields where is not easy to change the battery for a node and that may decrease the efficiency of that node and that may affect the network traffic may be interrupted because one or more nodes stop working. In this paper we implement, simulate, and investigate S-MAC protocol with mobility support and show the sequence of events the sender and receiver go through. We tested some parameters and their impacts of on the performance including System throughput, number of packets successfully delivered per second, packet delay, average packet delay before successful transmission.

• Journal of Sensor Science and Technology
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• v.19 no.4
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• pp.297-305
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• 2010

A home healthcare system based wireless sensor network, which can continuously monitor and manage the elderly's electrocardiogram(ECG) signal at any space at home without space limit is proposed. The communication coverage of wireless network is expended by multi-hop wireless sensor network. In order to send the elderly's ECG data wirelessly, a small size ECG sensor node was designed to forward the ECG data over multi-hop relay network. The packet acquired by mobile ECG node is transmitted through wireless intermediate nodes to base station for analyzing the packet reception rate. Modified minimum cost forwarding(MMCF) protocol and flooding protocol are designed and implemented to check the transmission efficiency of a packet in a wireless sensor network. The developed MMCF protocol shows an advantage of high reception rate by reduced network traffic.

• Journal of Computing Science and Engineering
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• v.2 no.4
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• pp.412-427
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• 2008

We propose ID-exchange protocol for Connectionless Location-Awareness Service (CLAS) to locate mobile nodes in indoor sensor network. When adapting location-awareness service to sensor network, the target system must be designed in accordance with various metrics which reflect the system requirement. We especially consider sustainability of the existing service which has been provided for its original purpose, such as environmental monitoring. The detailed meaning of sustainability here is that, even if location-awareness service is newly added to the existing service, the system must be assured to retain a stable network condition, and to deal with newly caused traffic properly. The CLAS ID-exchange protocol is especially designed for fixture and mobile nodes communication to achieve these properties. The protocol operates on 802.15.4 MAC layer to make mobile node work independently of the procedure to build routing table of fixture node, so a stable routing condition can be achieved even if there are many mobile nodes. Moreover, the dedicated frequency channel is assigned only for this protocol, so that traffic caused by location-awareness service can be distributed to another channel. A real system adapting the protocol was implemented to monitor fire and authorities' positions. We verified the overhead and elapsed time for location-awareness. The result shows the proposed protocol has a high performance in detecting speed, traffic distribution, and stability of overall network.

• Industrial Engineering and Management Systems
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• v.15 no.3
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• pp.268-277
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• 2016

Load balancing is a significant technique to prolong a network's lifetime in sensor network. This paper introduces a hybrid approach named as Load Distributing Hybrid Routing Protocol (LDHRP) composed with a border node routing protocol (BDRP) and greedy forwarding (GF) strategy which will make the routing effective, especially in mobility scenarios. In an existing solution, because of the high network complexity, the data delivery latency increases. To overcome this limitation, a new approach is proposed in which the source node transmits the data to its respective destination via border nodes or greedily until the complete data is transmitted. In this way, the whole load of a network is evenly distributed among the participating nodes. However, border node is mainly responsible in aggregating data from the source and further forwards it to mobile sink; so there will be fewer chances of energy expenditure in the network. In addition to this, number of hop counts while transmitting the data will be reduced as compared to the existing solutions HRLBP and ZRP. From the simulation results, we conclude that proposed approach outperforms well than existing solutions in terms including end-to-end delay, packet loss rate and so on and thus guarantees enhancement in lifetime.

• International Journal of Internet, Broadcasting and Communication
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• v.12 no.3
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• pp.156-162
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• 2020

Wireless Sensor Network (WSN) field is mainly studied to monitor and characterize large-scale physical environments to track various environmental or physical conditions, such as temperature, pressure, wind speed and humidity. WSN can be used in various applications such as wild surveillance, military target tracking and monitoring, dangerous environmental exploration and natural disaster relief. We design probabilistic mobile models that apply to mobile ad hoc network mobile environments. A probabilistic shift model proposed by dividing the number of moving nodes and the distance of travel into two categories to express node movement characteristics. The proposed model of movement through simulation was compared with the existing random movement model, ensuring that the width and variation rate of the first node node node node (FND) was stable regardless of the node movement rate. In addition, when the proposed mobile model is applied to the routing protocol, the superiority of network life can be verified from measured FND values. We overcame the limitations of the existing random movement model, showing excellent characteristics in terms of energy efficiency and stable in terms of changes in node movement.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1916-1917
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• 2011

A development of a new moving obstacle avoidance algorithm using a delay-time Compensation for a network-based autonomous mobile robot is proposed in this paper. The moving obstacle avoidance algorithm is based on a Kalman filter through moving obstacle estimation and a Bezier curve for path generation. And, the network-based mobile robot, that is a unified system composed of distributed environmental sensors, mobile actuators, and controller, is compensated by a network delay compensation algorithm for degradation performance by network delay. The network delay compensation method by a sensor fusion using the Kalman filter is proposed for the localization of the robot to compensate both the delay of readings of an odometry and the delay of reading of environmental sensors. Through some simulation tests, the performance enhancement of the proposed algorithm in the viewpoint of efficient path generation and accurate goal point is shown here.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.8
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• pp.1082-1087
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• 2021

In MANET(mobile ad hoc network), Mobility models vary according to the application-specific goals. The most widely used Random WayPoint Mobility Model(RWPMM) is advantageous because it is simple and easy to implement, but the random characteristic of nodes' movement is not enough to express the mobile characteristics of the entire sensor nodes' movements. The random mobility model is insufficient to express the inherent movement characteristics of the entire sensor nodes' movements. In the proposed Stochastic mobility model, To express the overall nodes movement characteristics of the network, the moving nodes are treated as random variables having a specific probability distribution characteristic. The proposed Stochastic mobility model is more stable and energy-efficient than the existing random mobility model applies to the routing protocol to ensure improved performances in terms of energy efficiency.

• Journal of the Korea Society of Computer and Information
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• v.25 no.5
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• pp.91-98
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• 2020

The mobile agent, which handles a given task while migrating between the sensor nodes, moves including the execution commands and task processing results. This increases the size of the mobile agent, causing the network to load, leading to the migration time delay and the loss of migration reliability. This paper presents the method of lightening the mobile agent using distributed object technology and the algorithm for exploring and providing the optimal migration path that is actively performed in the event of network traffic, and it proposes a method to ensure the reliability of the mobile agent migration by applying them. In addition, through the comparative analysis experiments based on agent size and network traffic for the migration time of mobile agent equipped with active rules in sensor network-based mobile agent middleware environment, applying the proposed methods proves to ensure the autonomy and migration reliability of the mobile agent.

• Journal of Computing Science and Engineering
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• v.9 no.4
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• pp.163-176
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• 2015

Self-organization of distributed wireless sensor nodes is a critical issue in wireless sensor networks (WSNs), since each sensor node has limited energy, bandwidth, and scalability. These issues prevent sensor nodes from actively collaborating with the other types of sensor nodes deployed in a typical heterogeneous and somewhat hostile environment. The automated self-organization of a WSN becomes more challenging as the number of sensor nodes increases in the network. In this paper, we propose a dynamic self-organized architecture that combines tree topology with a drawn-grid algorithm to automate the self-organization process for WSNs. In order to make our proposed architecture scalable, we assume that all participating active sensor nodes are unaware of their primary locations. In particular, this paper presents two algorithms called active-tree and drawn-grid. The proposed active-tree algorithm uses a tree topology to assign node IDs and define different roles to each participating sensor node. On the other hand, the drawn-grid algorithm divides the sensor nodes into cells with respect to the radio coverage area and the specific roles assigned by the active-tree algorithm. Thus, both proposed algorithms collaborate with each other to automate the self-organizing process for WSNs. The numerical and simulation results demonstrate that the proposed dynamic architecture performs much better than a static architecture in terms of the self-organization of wireless sensor nodes and energy consumption.