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Energy conservation in wireless sensor networks: A survey
"... In the last years, wireless sensor networks (WSNs) have gained increasing attention from both the research community and actual users. As sensor nodes are generally battery-powered devices, the critical aspects to face concern how to reduce the energy consumption of nodes, so that the network lifeti ..."
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Cited by 227 (11 self)
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In the last years, wireless sensor networks (WSNs) have gained increasing attention from both the research community and actual users. As sensor nodes are generally battery-powered devices, the critical aspects to face concern how to reduce the energy consumption of nodes, so that the network lifetime can be extended to reasonable times. In this paper we first break down the energy consumption for the components of a typical sensor node, and discuss the main directions to energy conservation in WSNs. Then, we present a systematic and comprehensive taxonomy of the energy conservation schemes, which are subsequently discussed in depth. Special attention has been devoted to promising solutions which have not yet obtained a wide attention in the literature, such as techniques for energy efficient data acquisition. Finally we conclude the paper with insights for research directions about energy conservation in WSNs.
An adaptive strategy for energy-efficient data collection in sparse wireless sensor networks
- In EWSN
, 2010
"... Abstract. Sparse wireless sensor networks (WSNs) are being effectively used in several applications, which include transportation, urban safety, environment monitoring, and many others. Sensor nodes typically transfer acquired data to other nodes and base stations. Such data transfer operations are ..."
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Cited by 14 (2 self)
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Abstract. Sparse wireless sensor networks (WSNs) are being effectively used in several applications, which include transportation, urban safety, environment monitoring, and many others. Sensor nodes typically transfer acquired data to other nodes and base stations. Such data transfer operations are critical, especially in sparse WSNs with mobile elements. In this paper, we investigate data collection in sparse WSNs by means of special nodes called Mobile Data Collectors (MDCs), which visit sensor nodes opportunistically to gather data. As contact times and other information are not known a priori, the discovery of an incoming MDC by the static sensor node becomes a critical task. Ideally, the discovery strategy should be able to correctly detect contacts while keeping a low energy consumption. In this paper, we propose an adaptive discovery strategy that exploits distributed independent reinforcement learning to meet these two necessary requirements. We carry out an extensive simulation analysis to demonstrate the energy efficiency and effectiveness of the proposed strategy. The obtained results show that our solution provides superior performance in terms of both discovery efficiency and energy conservation. 1
Performance Analysis of a Hierarchical Discovery Protocol for WSNs with Mobile Elements
"... Abstract—Wireless Sensor Networks (WSNs) are emerging as an effective solution for a wide range of real-life applications. In scenarios where a fine-grain sensing is not required, sensor nodes can be sparsely deployed in strategic locations and special Mobile Elements (MEs) can be used for data coll ..."
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Cited by 2 (1 self)
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Abstract—Wireless Sensor Networks (WSNs) are emerging as an effective solution for a wide range of real-life applications. In scenarios where a fine-grain sensing is not required, sensor nodes can be sparsely deployed in strategic locations and special Mobile Elements (MEs) can be used for data collection. Since communication between a sensor node and a ME can occur only when they are in the transmission range of each other, one of the main challenges in the design of a WSN with MEs is the energy-efficient and timely discovery of MEs. In this paper, we consider a hierarchical ME discovery protocol, namely Dual beacon Discovery (2BD) protocol, based on two different beacon messages emitted by the ME (i.e., Long-Range Beacons and Short-Range Beacons). We develop a detailed analytical model of 2BD assuming a sparse network scenario, and derive the optimal parameter values that minimize the energy consumption at sensor nodes, while guaranteeing the minimum throughput required by the application. Finally, we compare the energy efficiency and performance of 2BD with those of a traditional discovery protocol based on a single beacon. Our results show that 2BD can provide significant energy savings, especially when the discovery phase is relatively long.
Multiple Heterogeneous Data Ferry Trajectory Planning in Wireless Sensor Networks
, 2014
"... This paper investigates two new groups of trajectory optimization problems which stem from networked multi-robotic systems. In particular, we study how to efficiently collect data from stationary sensor nodes using multiple robotic vehicles such as data ferries under different circumstance. The fir ..."
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Cited by 2 (0 self)
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This paper investigates two new groups of trajectory optimization problems which stem from networked multi-robotic systems. In particular, we study how to efficiently collect data from stationary sensor nodes using multiple robotic vehicles such as data ferries under different circumstance. The first group includes two new problems which aim to find the tours and the paths, respectively, of k robot vehicles with different mobilization conditions to collect data from ground sensor nodes with minimum latency. The second group consists of one new problem whose goal is to determine the quality tours of k robot vehicles with different speeds, where each of which follows its corresponding tour to repeatedly collect data from stationary sensors. We prove the three problems are NP-hard and propose constant factor approximation strategies for them. Through a simulation, an analytical study is conducted to evaluate the average performance of our core contribution.
Reliable data delivery in sparse WSNs with multipe mobile sinks: an experimental analysis
, 2011
"... Abstract—Urban sensing is emerging as a significant Wireless Sensor Networks (WSNs) application. In such a scenario, static sensors are sparsely deployed in an urban area to collect environmental information. Sensed data are opportunistically collected by Mobile Sinks (MSs), which can be other senso ..."
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Abstract—Urban sensing is emerging as a significant Wireless Sensor Networks (WSNs) application. In such a scenario, static sensors are sparsely deployed in an urban area to collect environmental information. Sensed data are opportunistically collected by Mobile Sinks (MSs), which can be other sensor nodes attached to cars or buses, or carried by people while they move around the city. Since the contacts between the MSs and the static sensors are infrequent and short, reliable and energy efficient data collection is a primary concern of such applications. To this end, we exploit a hybrid data delivery scheme based on both Erasure Coding (EC) and feedback by the MSs. We provide an optimized implementation, and show by extensive experiments in a real testbed that the proposed approach is feasible, despite the very limited storage and processing resources of commercially available sensor platforms. Keywords-Urban sensing, wireless sensor networks, mobile sinks, reliable data delivery, erasure coding, implementation. I.
Analysis and Optimization of a Protocol for Mobile Element Discovery in Sensor Networks
"... Abstract—Recent studies have demonstrated that mobile elements (MEs) are an efficient solution to help decrease dramatically energy consumption in wireless sensor networks (WSNs). However, in most of cases, sensors use duty cycle schemes to save energy, and unless the ME mobility pattern is determin ..."
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Cited by 1 (0 self)
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Abstract—Recent studies have demonstrated that mobile elements (MEs) are an efficient solution to help decrease dramatically energy consumption in wireless sensor networks (WSNs). However, in most of cases, sensors use duty cycle schemes to save energy, and unless the ME mobility pattern is deterministic, each sensor node has to discover the presence of the ME in the nearby area before starting to exchange data with it. Therefore, in such wireless sensor networks with mobile elements (in short, WSN-MEs), the definition and analysis of a protocol for efficient ME discovery becomes of fundamental importance. In this paper, we propose an extensive performance analysis of an easy-to-implement, hierarchical discovery protocol for WSN-MEs, called Dual Beacon Discovery (2BD) protocol, taking into account stochastic, multi-path, variable speed ME mobility patterns. We also derive the optimal parameter values that minimize the energy consumption of sensor nodes, while guaranteeing the minimum node throughput required by the applications under consideration. Finally, we compare the 2BD protocol with a classical solution based on Periodic Listening (PL). Our results show that 2BD can exploit its hierarchical mechanism and thus significantly increase lifetime, especially when the ME discovery phase is relatively long.
Accessing Data Transfer Reliability for Duty Cycled Mobile Wireless Sensor Network
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Error Correcting Codes in Wireless Sensor Networks: An Energy Perspective
, 2015
"... Abstract: Wireless Sensor Networks (WSNs) are energy constraint networks that require reliable data communication at a low cost of energy. Only one particular error correcting code (ECC) cannot be adopted for all applications and scenarios of WSNs. The use of a specific ECC depends on the requireme ..."
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Abstract: Wireless Sensor Networks (WSNs) are energy constraint networks that require reliable data communication at a low cost of energy. Only one particular error correcting code (ECC) cannot be adopted for all applications and scenarios of WSNs. The use of a specific ECC depends on the requirements of the application and the constraints of the WSN. Hence it is very challenging to choose an optimum error correcting code for a WSN where both, the performance and energy consumption are taken into account. The selection of an optimum error correcting code for wireless sensor network has been widely studied by many researchers in the past but a standard is yet to be set. Therefore, we present a survey paper to provide reference of existing work on ECCs in WSN and help scholars find a standard ECC for WSNs. We survey different techniques used for error correction in WSNs. Furthermore we study the implementation strategies of error control techniques in WSNs and analyze some energy models to find the energy efficiency of different ECCs. The performance of various ECCs is evaluated on the basis of stated energy models and optimization criteria. Based on the comparison, we can identify the code that would be suitable for a particular implementation strategy.
An Efficient Group Key Distribution Security Scheme in Wireless Sensor Networks
"... collects the sensing data by using mobile sinks (MSs). It differs from the traditional multi- hop wireless sensor networks in which unbalanced traffic makes the sensors close to the base station deplete their power earlier than others. An UWSN can save the battery power and prolong the network lifet ..."
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collects the sensing data by using mobile sinks (MSs). It differs from the traditional multi- hop wireless sensor networks in which unbalanced traffic makes the sensors close to the base station deplete their power earlier than others. An UWSN can save the battery power and prolong the network lifetime. Unfortunately, MSs would be given too much privilege when acting as the collecting base station, which will cause security concern if Replicated. Besides, UWSNs are usually deployed in unreachable and hostile environments, where sensors can be easily Replicated. Thus, their security issues should be carefully addressed to deal with node compromise. In this paper, we present a novel key management scheme to secure UWSNs. We employ the Blundo symmetric polynomial mechanism to guard against the newly Replicated nodes in a period while utilizing the periodic key updating based on the reverse hash chain to block the Replicated nodes and revoke the Replicated MSs if failing the authentication. We show that our scheme is robust against node Replicated attacks and carry out comparison analysis on the intrusion-tolerance ratio, communication and computing overhead. Index Terms- wireless sensor networks; security; key management; mobile sink. A I.
www.mdpi.com/journal/remotesensing Article Model-Free Trajectory Optimisation for Unmanned Aircraft Serving as Data Ferries for Widespread Sensors
, 2012
"... Abstract: Given multiple widespread stationary data sources such as ground-based sensors, an unmanned aircraft can fly over the sensors and gather the data via a wireless link. Performance criteria for such a network may incorporate costs such as trajectory length for the aircraft or the energy requ ..."
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Abstract: Given multiple widespread stationary data sources such as ground-based sensors, an unmanned aircraft can fly over the sensors and gather the data via a wireless link. Performance criteria for such a network may incorporate costs such as trajectory length for the aircraft or the energy required by the sensors for radio transmission. Planning is hampered by the complex vehicle and communication dynamics and by uncertainty in the locations of sensors, so we develop a technique based on model-free learning. We present a stochastic optimisation method that allows the data-ferrying aircraft to optimise data collection trajectories through an unknown environment in situ, obviating the need for system identification. We compare two trajectory representations, one that learns near-optimal trajectories at low data requirements but that fails at high requirements, and one that gives up some performance in exchange for a data collection guarantee. With either encoding the ferry is able to learn significantly improved trajectories compared with alternative heuristics. To demonstrate the versatility of the model-free learning approach, we also learn a policy to minimise the radio transmission energy required by the sensor nodes, allowing prolonged network lifetime.
