• Journal of the Korea Society of Computer and Information
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• v.22 no.9
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• pp.33-40
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• 2017

In this paper, we propose a sink-location management and data-routing scheme to effectively support the mobile sink in solar-powered WSN. Battery-based wireless sensor networks (WSNs) have a limited lifetime due to their limited energy, but solar energy-based WSNs can be supplied with energy periodically and can operate forever. On the other hand, introduction of mobile sink in WSNs can solve some energy unbalance problem between sink-neighboring nodes and outer nodes which is one of the major challenges in WSNs. However, there is a problem that additional energy should be consumed to notify each sensor node of the location of the randomly moving mobile sink. In the proposed scheme, one of the nodes that harvests enough energy in each cluster are selected as the cluster head, and the location information of the mobile sink is shared only among the cluster heads, thereby reducing the location management overhead. In addition, the overhead for setting the routing path can be removed by transferring data in the opposite direction to the path where the sink-position information is transferred among the heads. Lastly, the access node is introduced to transmit data to the sink more reliably when the sink moves frequently.

• Journal of Electrical Engineering and Technology
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• v.12 no.3
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• pp.1307-1313
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• 2017

Sensor networks are composed of provide low powered, inexpensive distributed devices which can be deployed over enormous physical spaces. Coordination between sensor devices is required to achieve a common communication. In low cost, low power and short-range wireless environment, sensor networks cope with significant resource constraints. Security is one of main issues in wireless sensor networks because of potential adversaries. Several security protocols and models have been implemented for communication on computing devices but deployment these models and protocols into the sensor networks is not easy because of the resource constraints mentioned. Memory intensive encryption algorithms as well as high volume of packet transmission cannot be applied to sensor devices due to its low computational speed and memory. Deployment of sensor networks without security mechanism makes sensor nodes vulnerable to potential attacks. Therefore, attackers compromise the network to accept malicious sensor nodes as legitimate nodes. This paper provides the different security models as a metric, which can then be used to make pertinent security decisions for securing wireless sensor network communication.

• IEIE Transactions on Smart Processing and Computing
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• v.2 no.2
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• pp.57-66
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• 2013

Wireless Sensor Networks consist of small, inexpensive, low-powered sensor nodes that communicate with each other. To achieve a low communication cost in a resource constrained network, a novel concept of signcryption has been applied for secure communication. Signcryption enables a user to perform a digital signature for providing authenticity and public key encryption for providing message confidentiality simultaneously in a single logical step with a lower cost than that of the sign-then-encrypt approach. Ring signcryption maintains the signer's privacy, which is lacking in normal signcryption schemes. Signcryption can provide confidentiality and authenticity without revealing the user's identity of the ring. This paper presents the security notions and an evaluation of an ID-based ring signcryption scheme for wireless sensor networks. The scheme has been proven to be better than the existing schemes. The proposed scheme was found to be secure against adaptive chosen ciphertext ring attacks (IND-IDRSC-CCA2) and secure against an existential forgery for adaptive chosen message attacks (EF-IDRSC-ACMA). The proposed scheme was found to be more efficient than scheme for Wireless Sensor Networks reported by Qi. et al. based on the running time and energy consumption.

• Journal of Korea Multimedia Society
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• v.21 no.5
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• pp.592-598
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• 2018

In wireless sensor networks where there is no centralized base station, each node has limited transmission range and the multi-hop routing for transmitting data to the destination is the one of the important technical issues. In particular, the wireless sensor network is not powered by external power source but operates by its own battery, so it is required to maximize the network life through efficient use of energy. To balance the power consumption, the residual power based adaptive power control is required in routing protocol. In this paper, we propose a routing protocol that prolongs the network lifetime by balancing the power consumption among the nodes by controlling the transmit power according to the residual power. We evaluate the proposed routing protocol using extensive simulation, and the results show that the proposed routing scheme can balance the power consumption and prolong network lifetime.

• Journal of IKEEE
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• v.13 no.3
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• pp.39-46
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• 2009

Wireless sensor networks consist of small, autonomous devices with wireless networking capabilities. In order to further increase the applicability in real world applications, minimizing energy consumption is one of the most critical issues. Therefore, accurate energy model is required for the evaluation of wireless sensor networks. In this paper we analyze the power consumption for wireless sensor networks. To develop the power consumption model, we have measured the power characteristics of commercial Kmote node based on TelosB platforms running TinyOS. Based on our model, the estimated lifetime of a battery powered sensor node can use about 6.9 months for application of human detection using PIR sensors. This result indicates that sensor nodes can be used in a monitoring system for elderly living alone.

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.264-266
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• 2005

Recently, on-line diagnosis methods through wired and wireless networks are widely adopted in the diagnosis of industrial Electric Facilities, such as generators, transformers and motors. Also smart sensors which includes sensors, signal conditioning circuits and micro-controller in one board are widely studied in the field of condition monitoring. This paper suggests an self-powered system suitable for condition-monitoring smart sensors, which uses parasitic vibrations of the facilities as energy source. First, vibration-driven noise patterns of the electric facilities are presented. And then, an electromagnetic generator which uses mechanical mass-spring vibration resonance are suggested and designed. Finally energy consumption of the presented smart sensor, which consists of MEMS vibration sensors, signal conditioning circuits, a low-power consumption micro-controller, and a ZIGBEE wireless tranceiver, are presented. The usefulness and limits of the presented electromagnetic generators in the field of electric facility monitoring are also suggested.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.860-863
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• 2010

Wireless sensor networks consist of small, autonomous devices with wireless networking capabilities. In order to further increase the applicability in real world applications, minimizing energy consumption is one of the most critical issues. Therefore, accurate energy model is required for the evaluation of wireless sensor networks. In this paper, we analyze the energy consumption for wireless sensor networks. To estimate the lifetime of sensor node, we have measured the energy characteristics of sensor node based on Telosb platforms running TinyOS. Based on the proposed model, the estimated lifetime of a battery powered sensor node can use about 6.925 months for 10 times motion detection per hour.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.371-372
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• 2008

In this paper, we consider wireless sensor networks with hard energy constraint, where each node is powered by a small battery. Under this hard constraint, reducing energy consumption is the most important design consideration for wireless sensor networks. Energy saving and control is an important issue, involved in the design of most sensor nodes. In this context, we focus on physical layer design where energy constraint problem can be modeled as an optimization of transmission modulation scheme[1]. Specifically, our analyses are based on energy control schemes that are relative to physical layer design on upper bound SEP MPSK in AWGN channels.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.1900-1911
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• 2015

In this paper, we introduce backscatter communication for power-limited sensors to enable long-range transmission in wireless sensor networks, and envision a way to avoid doubly near-far problem in wireless-powered communication network (WPCN) with this technology. In backscatter based WPCN, users harvest energy from both the signal broadcasted by the hybrid access point and the carrier signal transmitted by the carrier emitter in the downlink, and then transmit their own information in a passive way via the reflection of the carrier signal using frequency-shift keying modulation in the uplink. We characterize the energy-free condition and the signal-to-noise ratio (SNR) outage zone in backscatter based WPCN. Further, we propose backscatter based harvest-then-transmit protocol to maximize the sum-throughput of the backscatter based WPCN by optimally allocating time for energy harvesting and information transmission. Numerical results demonstrate that the backscatter based WPCN increases significantly the transmission range and diminishes greatly the SNR outage zone.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.8
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• pp.694-701
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• 2013

This paper deals with the problem of accurately tracking a single target moving through UWSNs (Underwater Wireless Sensor Networks) by employing underwater acoustic sensors. This paper addresses the issues of estimating the states of the target, and improving energy efficiency by applying a Kalman filter in a distributed architecture. Each underwater wireless sensor nodes composing the UWSNs is battery-powered, so the energy conservation problem is a critical issue. This paper provides an algorithm which increases the energy efficiency of each sensor node through WuS (Waked-up/Sleeping) and VM (Valid Measurement) selecting schemes. Simulation results illustrate the performance of the distributed tracking filter.