• Journal of Information Processing Systems
• /
• v.11 no.2
• /
• pp.205-228
• /
• 2015

In this paper, we present a virtual laboratory platform (VLP) baptized Mercury allowing students to make practical work (PW) on different aspects of mobile wireless sensor networks (WSNs). Our choice of WSNs is motivated mainly by the use of real experiments needed in most courses about WSNs. These experiments require an expensive investment and a lot of nodes in the classroom. To illustrate our study, we propose a course related to energy efficient and safe weighted clustering algorithm. This algorithm which is coupled with suitable routing protocols, aims to maintain stable clustering structure, to prevent most routing attacks on sensor networks, to guaranty energy saving in order to extend the lifespan of the network. It also offers a better performance in terms of the number of re-affiliations. The platform presented here aims at showing the feasibility, the flexibility and the reduced cost of such a realization. We demonstrate the performance of the proposed algorithms that contribute to the familiarization of the learners in the field of WSNs.

• Journal of Sensor Science and Technology
• /
• v.19 no.1
• /
• pp.17-24
• /
• 2010

This paper describes a real time reliable monitoring method and analysis system using wrist type oximeter for ubiquitous healthcare service based on IEEE 802.15.4 standard. Photoplethysmograph(PPG) is simple and cost effective technique to measure blood volume change. In order to obtain and monitor physiological body signals continuously, a small size and low power consumption wrist type oximeter is designed for the measurement of oxygen saturation of a patient unobtrusively. The measured data is transferred to a central PC or server computer by using wireless sensor nodes in wireless sensor network for storage and analysis purposes. LabVIEW server program is designed to monitor stress indicator from heart rate variability(HRV) and process the measured PPG to accelerated plethysmograph(APG) by appling second order derivatives in server PC. These experimental results demonstrate that APG can precisely describe the features of an individual's PPG and be used as estimation of vascular elasticity for blood circulation.

• Journal of Korea Society of Digital Industry and Information Management
• /
• v.4 no.4
• /
• pp.41-49
• /
• 2008

Sensor networks are often deployed in unattended environments, thus leaving these networks vulnerable to false data injection attacks in which an adversary injects forged reports into the network through compromised nodes. Such attacks by compromised sensors can cause not only false alarms but also the depletion of the finite amount of energy in a battery powered network. In order to reduce damage from these attacks, several security solutions have been proposed. Researchers have also proposed some techniques to increase the energy-efficiency of such security solutions. In this paper, we propose a CH(Cluster Header) selection algorithm to choose low power delivery method in sensor networks. The CNP(Contract Net Protocol), which is an approach to solve distribution problems, is applied to choose CHs for event sensing. As a result of employing CNP, the proposed method can prevent dropping of sensing reports with an insufficient number of message authentication codes during the forwarding process, and is efficient in terms of energy saving.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.9
• /
• pp.4442-4466
• /
• 2016

This paper proposes a privacy-preserving aggregation scheme based on the designed P-Gene (PAPG) for sensor networks. The P-Gene is constructed using the designed erasable data-hiding technique. In this P-Gene, each sensory data item may be hidden by the collecting sensor node, thereby protecting the privacy of this data item. Thereafter, the hidden data can be directly reported to the cluster head that aggregates the data. The aggregation result can then be recovered from the hidden data in the cluster head. The designed P-Genes can protect the privacy of each data item without additional data exchange or encryption. Given the flexible generation of the P-Genes, the proposed PAPG scheme adapts to dynamically changing reporting nodes. Apart from its favorable resistance to data loss, the extensive analyses and simulations demonstrate how the PAPG scheme efficiently preserves privacy while consuming less communication and computational overheads.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.2
• /
• pp.515-524
• /
• 2013

For the development of reliable software, Software testing is the most important. Recently small changes of the software according to the importance of regression testing is growing. To verify Application of a large number of nodes, Network simulator environment is required. This paper proposed interface module between network framework for sensor network application and co-simulator to unit test sensor network application. To conclude, developer can focus on sensor network application implementation only, so the improved integrated simulator contributes to increase development productivity.

• Journal of Information Processing Systems
• /
• v.6 no.2
• /
• pp.177-184
• /
• 2010

Secure routing is vital to the acceptance and use of Wireless Sensor Networks (WSN) for many applications. However, providing secure routing in WSNs is a challenging task due to the inherently constrained capabilities of sensor nodes. Although a wide variety of routing protocols have been proposed for WSNs, most do not take security into account as a main goal. Routing attacks can have devastating effects on WSNs and present a major challenge when designing robust security mechanisms for WSNs. In this paper, we examine some of the most common routing attacks in WSNs. In particular, we focus on the wormhole routing attack in some detail. A variety of countermeasures have been proposed in the literature for such attacks. However, most of these countermeasures suffer from flaws that essentially render them ineffective for use in large scale WSN deployments. Due to the inherent constraints found in WSNs, there is a need for lightweight and robust security mechanisms. The examination of the wormhole routing attack and some of the proposed countermeasures makes it evident that it is extremely difficult to retrofit existing protocols with defenses against routing attacks. It is suggested that one of the ways to approach this rich field of research problems in WSNs could be to carefully design new routing protocols in which attacks such as wormholes can be rendered meaningless.

• Journal of KIISE:Information Networking
• /
• v.36 no.2
• /
• pp.108-117
• /
• 2009

Data aggregation is one of the well-known techniques to reduce the energy consumption for information transmission over wireless sensor networks (WSN). As the WSNs are deployed in untrusted or even hostile environments, the data aggregation becomes problematic when end-to-end data privacy including data confidentiality and integrity between sensor nodes and base station, is required. Meanwhile, data homomorphic cryptoschemes have been investigated recently and recommended to provide the end-to-end privacy in the hostile environments. In order to assure both data confidentiality and integrity for data aggregation, this paper analyzes the existing homomorphic cryptoschemes and digital signature schemes, proposes possible combinations, and evaluates their performance in terms of CPU overheads and communication costs.

• Journal of Advanced Navigation Technology
• /
• v.17 no.2
• /
• pp.218-224
• /
• 2013

Uplink overflow in WMSN (Wireless Multimedia Sensor Networks) aggravates the resource consumption, delay, and traffic congestion. This paper proposes a new traffic congestion control mechanism using popularity. The proposed mechanism controls congestions by dispersing the media traffic, and it control fairly packets according to priority. This paper proposes PQS (Packet Queue Scheduler) to control fairly packets, and the proposed mechanism provides a fair opportunity to all sensor nodes without a specific location. The simulation results show that the proposed mechanism achieves improved performance in throughput, delay ratio, link quality, and buffer queue control ratio compared with those of other existing methods.

• Journal of Communications and Networks
• /
• v.12 no.4
• /
• pp.358-365
• /
• 2010

We develop a low complexity cooperative diversity protocol for low energy adaptive clustering hierarchy (LEACH) based wireless sensor networks. A cross layer approach is used to obtain spatial diversity in the physical layer. In this paper, a simple modification in clustering algorithm of the LEACH protocol is proposed to exploit virtual multiple-input multiple-output (MIMO) based user cooperation. In lieu of selecting a single cluster-head at network layer, we proposed M cluster-heads in each cluster to obtain a diversity order of M in long distance communication. Due to the broadcast nature of wireless transmission, cluster-heads are able to receive data from sensor nodes at the same time. This fact ensures the synchronization required to implement a virtual MIMO based space time block code (STBC) in cluster-head to sink node transmission. An analytical method to evaluate the energy consumption based on BER curve is presented. Analysis and simulation results show that proposed cooperative LEACH protocol can save a huge amount of energy over LEACH protocol with same data rate, bit error rate, delay and bandwidth requirements. Moreover, this proposal can achieve higher order diversity with improved spectral efficiency compared to other virtual MIMO based protocols.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.2B
• /
• pp.225-231
• /
• 2010

In this paper, a sensor network system for providing u-health services is suggested and is implemented. It steadily collects biological data of resident people and automatically detects emergency situations. LEID (Lighting Embedded Information Device) nodes are the most essential component of the sensor network. They embed sensor network technology into lightening devices which are indispensable to most living spaces. To verify practicality of the proposed u-health system, a prototypical system is realized in the Smart Home Industrialization Support Center at Kookmin University, and is tested within many practical circumstances. The proposed u-health system can be used at various places where many patients are continuously cared.