• Journal of Communications and Networks
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• v.11 no.1
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• pp.57-71
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• 2009

Networking together hundreds or thousands of cheap sensor nodes allows users to accurately monitor a remote environment by intelligently combining the data from the individual nodes. As sensor nodes are typically battery operated, it is important to efficiently use the limited energy of the nodes to extend the lifetime of the wireless sensor network (WSN). One of the fundamental issues in WSNs is the coverage problem. In this paper, the border coverage problem in WSNs is rigorously analyzed. Most existing results related to the coverage problem in wireless sensor networks focused on planar networks; however, three dimensional (3D) modeling of the sensor network would reflect more accurately real-life situations. Unlike previous works in this area, we provide distributed algorithms that allow the selection and activation of an optimal border cover for both 2D and 3D regions of interest. We also provide self-healing algorithms as an optimization to our border coverage algorithms which allow the sensor network to adaptively reconfigure and repair itself in order to improve its own performance. Border coverage is crucial for optimizing sensor placement for intrusion detection and a number of other practical applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.685-689
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• 2007

Recently, wireless communication technology and state of art miniaturization has enabled the wireless sensor network with Smart Environmental sensors. The sensor network is a new field which has been researched vigorously in the ubiquitous computing and Ad-hoc network. How to efficiently use the limited energy in this USN(Ubiquitous sensor Networks) has been debated recently. We utilized the Directed Diffusion and Gossiping concept which is based on the Large scale Glass greenhouse and present a method to prolong the lifespan of the sensor network by operating variable time based this routing information on the average energy leftover. In this paper, we present a method to minimize the energy consumption of sensor node within Glass greenhouses and ensure a stable network operation at the same time through energy efficient routing among sensor nodes.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.2
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• pp.6-13
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• 2011

This paper deals with the interconnection problem in ad-hoc networks or sensor networks, where relay nodes are deployed additionally to form connections between given nodes. This problem can be reduced to a NP-hard problem. The nodes of the networks, by applications or geographic factors, can be deployed densely in some areas while sparsely in others. For such a case one can make an approximation scheme, which gives shorter execution time, for the additional node deployments by ignoring the interconnections inside the dense area of nodes. However, the case is still a NP-hard, so it is proper to establish a polynomial time approximation scheme (PTAS) by implementing a dynamic programming. The analysis can be made possible by an elaboration on making the definition of the objective function. The objective function should be defined to be able to deal with the requirement incurred by the substitution of the dense area with its abstraction.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.1
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• pp.113-121
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• 2007

Commonly, in the Sensor Network that composed with multiple nodes uses Ad-hoc protocol to communicate each other. Each sensed data packets are collected by base node and processed by Host PC. But the Ad-hoc protocol is too vulnerable to Sinkhole attack, where the intruder attracts surrounding nodes with unfaithful routing information, and then performs selective forwarding or changes the data passing through it. The Sinkhole attack increases overhead over the network and boosts energy consumption speed to decrease network's life time. Since the other attacks can be easily adopted through sinkhole attack, the countermeasure must be considered carefully. In this paper, we proposed the Hop-depth algorithm that detects intruder in Sinkhole attack and colluded nodes. First, the proposed algorithm makes list of suspected nodes and identifies the real intruder in the suspected node list through the Hop-depth count value. And recalculates colluder's path information to find the real intruder. We evaluated the performance of the proposed algorithm using NS2. We compared and analyzed the success ratio of finding real intruder, false positive ratio, false negative ratio, and energy consumption.

• Journal of the Korea Society of Computer and Information
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• v.18 no.2
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• pp.77-85
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• 2013

Recently, location information based routing protocol has been studied to estimate end-to-end path in wireless ad-hoc network. This protocol assumes all nodes can get heir location information via GPS devices and floods only limited area with routing message through acquired location information. Therefore, this protocol has advantage that can reduce the number of routing message than the existing IP-based routing protocols. In addition, all nodes enabling this protocol must acquire their own location information to participate in the location-based routing. However, recent because of the miniaturization of sensor node, sensor node without GPS function has been launched. Therefore in case of the sensor node that does not know location information, it is impossible to participate in the ad hoc network configuration and location information based routing. In this paper, a virtual location information based routing scheme is proposed for wireless nodes without GPS function to be able to participate in location information based routing within ad hoc network environments consisting of wireless nodes with GPS function and wireless nodes without GPS function. Therefore, the proposed protocol has the advantage that a wireless node without a GPS function is able to participate in ad hoc network configuration and the location information based routing.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.502-504
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• 2021

The Mobile Ad-hoc Network (MANET) is a representative mobile sensor network. MANET is used in various areas because it consists of sensors composed of moving nodes that do not depend on existing infrastructure networks. In the mobile sensor field, the mobility characteristic plays an important role in the performance of the network. Researches on routing techniques are being actively developed in terms of energy efficiency of the entire network. Clustering-based routing protocols show excellent performance in terms of energy efficiency. In this paper, the energy performance according to routing protocols is compared in the MANET to which the same mobility model is adopted.

• The KIPS Transactions:PartC
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• v.11C no.7 s.96
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• pp.871-878
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• 2004

Recenty, there has been great interest in MANET from various areas. In this paper we focus on performance analysis of on demand routing protocols surf as DSR, AODV, and TORA in MANET. We have conducted several simulations concerned with application service data such as sensor, text. voice, and video data. And then, we have evaluated the performance of three protocols in a pre-designed ad hoc network, which is consisted of 20 nodes. As a result, we have obtained quantitative data for packet delivery fraction, average end to-end delay, routing load, channel utilization from upper layer and supportable routing protocol for application service data. The results can be used for designing specific-purposed ad-hoc networks.

• Journal of Information Technology Applications and Management
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• v.14 no.2
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• pp.1-10
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• 2007

The ubiquitous computing system is expected to be widely utilized in digital home, logistics control, environment/disaster management, medical/health-care services and other applications. The ubiquitous sensor network (USN) is a key infra-structure of this system. Nodes in the USN are exposed to adverse environments and required to perform their missions with very limited power supply only. Also the sensor network is composed of much more nodes. In case some node consumes up its power capacity under a certain required level, the network topology should change and re-routing/ re-transmission of data is necessitated. Resultantly communication protocols studied for conventional wireless networks or ad-hoc networks are not suitable for the sensor network. Schemes should be devised to control the efficient usage of node power in the sensor network. This paper proposes a routing algorithm to enhance the efficiency of power consumption for USN node and analyzes its performance by simulation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.413-417
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• 2007

Ad hoc 센서 네트워크에서 노드는 제한된 에너지를 가지며, 에너지의 사용률은 토폴로지 구조나 센서 노드의 동작에 의존한다. 본 논문에서는 low power distributed MAC을 개량 하여, MANET에서 clustering 구조의 네트워크를 위한 효율적인 에너지 절약을 위한 새로운 구조를 제안한다. 본 제안된 구조의 특징은 Ad hoc 네트워크에서 에너지에 관련된 배터리 파워나, 노드의 거리, 전송 전력 등의 정보를 활용한 상황 인식을 사용하였다. 에너지 상황 인식을 적용한 제안된 망의 구조는 clustering 형상과 메시지 전송의 성능 및 데이터의 도달 인식을 향성 시킨다. 또한 context aware computing을 이용함으로써, 상황과 정의된 rule에 따라서 노드의 동작과 네크워크 라우팅의 상황에 적응하도록 노드를 조정 할 수 있는 구조이다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.11
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• pp.2577-2596
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• 2013

In this paper, we present an Energy-Aware Self-Stabilizing Distributed Clustering protocol based on message-passing model for Ad Hoc networks. The latter does not require any initialization. Starting from an arbitrary configuration, the network converges to a stable state in a finite time. Our contribution is twofold. We firstly give the formal proof that the stabilization is reached after at most n+2 transitions and requires at most $n{\times}log(2n+{\kappa}+3)$ memory space, where n is the number of network nodes and ${\kappa}$ represents the maximum hops number in the clusters. Furthermore, using the OMNeT++ simulator, we perform an evaluation of our approach. Secondly, we propose an adaptation of our solution in the context of Wireless Sensor Networks (WSNs) with energy constraint. We notably show that our protocol can be easily used for constructing clusters according to multiple criteria in the election of cluster-heads, such as nodes' identity, residual energy or degree. We give a comparison under the different election metrics by evaluating their communication cost and energy consumption. Simulation results show that in terms of number of exchanged messages and energy consumption, it is better to use the Highest-ID metric for electing CHs.