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Wireless Sensor Network (WSN) supports different kinds of applications in distinct areas, such as military, health care, agriculture, home or industry automation and others. Generally, there are three models of WSN: continuous, on-demand and event-driven. In continuous model, sensors send data periodically to the sink. In on-demand model, sensors sense continuously, store the data and sends only when...
Energy Harvesting (EH) nodes, which harvest energy from the environment in order to communicate over a wireless link, promise perpetual operation of a wireless network with battery-powered nodes. In this paper, we address the throughput optimization problem for a rate-adaptive EH node that chooses its rate from a set of discrete rates and adjusts its power depending on its channel gain and battery...
In wireless sensor networks (WSNs), sensor nodes are typically power-constrained with limited lifetime, and thus it is necessary to know how long the network sustains its networking operations. We consider the network lifetime as the time until that a majority of functional nodes remains connected of one another, forming a giant component, in the network. We then analytically examine such network...
This paper presents an empirical study of the effects of the channel occupation on the consumption of actual IEEE 802.15.4/ZigBee motes. The study is focused on the current demanded by a sensor node in a simple beaconless star topology when the CSMA contention algorithm introduces idle times in the activity of the radio transceiver. For this purpose, the developed testbed permits to define the probability...
Sensors equipped with energy harvesting and cooperative communication capabilities are a viable solution to the power limitations of Wireless Sensor Networks (WSNs) associated with current battery technology. However, the optimal scheduling of transmissions in such networks is challenging due to the requirement of complete state information of the relay nodes. This paper addresses the problem of transmission...
In wireless networks environment, nodes are powered by exhaustible energy provided by batteries with limited duration. When the energy budget of a node comes to exhaustion, many undesirable situations may occur, ranking from minor alternative route discovery to unbearable network partition. Another situation which has not yet paid attention is one reached when a distributed application requires more...
Limited energy resources in wireless sensor networks (WSNs) call for a comprehensive cross-layer analysis of energy consumption in a multi-hop network. In this paper, we provide a stochastic analysis of the energy consumption in a random network environment. Accordingly, a comprehensive cross-layer analysis framework, which employs a stochastic queueing model in realistic channel environments, is...
This paper presents an energy efficient multipath routing protocol specifically designed for wireless sensor networks (referred as RELAX). RELAX protocol tries to utilize the relaxation phenomenon of certain batteries to increase the battery lifetime and hence increasing the overall lifetime of the sensor network. Relaxation periods enable the battery to recover a portion of its lost power; it has...
Wireless Sensor Networks Powered by Ambient Energy Harvesting (WSN-HEAP) can perform the task of continuous and remote monitoring of the environment without the need for replacement of batteries. We identify three important design considerations for wireless networking protocols in WSN-HEAP: the unpredictable energy supply, the propagation losses in different environments and the suitable power level...
Sensors equipped with energy harvesting capabilities are a viable solution to the limitations of current battery technology associated with wireless sensor networks (WSNs). This paper addresses the problem of developing energy efficient transmission strategies for WSNs with energy harvesting capabilities and cooperative transmission options. Taking into account the energy harvesting capabilities of...
Solar-powered sensor nodes have incentive to spend extra energy, especially when the battery is fully charged, because this energy surplus would be wasted otherwise. In this paper, we consider the problem of utilizing such energy surplus to adaptively adjust the redundancy level of erasure codes used in communication, so that the delivery reliability is improved while the network lifetime is still...
Energy harvesting sensor platforms have opened up a new dimension to the design of network protocols. In order to sustain the network operation, the energy consumption rate cannot be higher than the energy harvesting rate, otherwise, sensor nodes will eventually deplete their batteries. In contrast to traditional network resource allocation problems where the resources are static, the time-varying...
Energy harvesting sensors (EHS), which harvest energy from the environment in order to sense and then communicate their measurements over a wireless link, provide the tantalizing possibility of perpetual lifetime operation of a sensor network. The wireless communication link design problem needs to be revisited for these sensors as the energy harvested can be random and small and not available when...
A number of important characteristics of wireless sensor networks such as the lifetime, connectivity and coverage are determined the residual power levels of the nodes in the network. This paper presents a general framework for modeling the availability of power at sensor nodes as a function of time. Models are developed for sensors with and without battery recharging and expressions are derived for...
Decentralized protocols offer high adaptability to topology changes prominent in Wireless Sensor Networks (WSN). Protocols resilient to topology changes stemming from nodes dying, being added, relocating or duty cycling, improve network performance in terms of lifetime and percent of events sensed and reported. Topology dependant protocols, such as cluster-based, face many hindrances especially in...
Although current research focused on sensor deployment to balance the energy consumption among the sensor nodes for prolonging the lifetime of wireless sensor networks, sensor nodes with larger communication radius have to consume more energy to overcome wireless channel fading and path loss. Cooperative transmission allows nodes with single-antenna to cooperate on information transmission and/or...
As sensor nodes are powered by battery of limited lifespan, energy consumption has always been an important issue in sensor networks. New generation of sensor network technology bring about the possibility of constructing a spatial index over a sensor network such that sensor queries are forwarded only to the relevant nodes. Existing spatial indices share the common feature of using the same node...
In order to solve the problem of short continuous driving mileage and long charging time of electric vehicle (EV), the method of auto and rapid exchange system of EV battery cases is proposed. The exchange system deals with corresponding control of multi-components which are relatively moving each other. Based on single chip wireless transceiver nRF905 and MC68HC908GZ16, the wireless communication...
A node in a wireless sensor network typically consists of a micro-controller, a communication device or transceiver, and a battery unit for powering the transceiver and other devices. An important feature of wireless sensor networks is the low power consumption requirement, since these sensor nodes carry generally irreplaceable power sources or batteries. We consider the problem of assigning a power...
We study a sensor node with an energy harvesting source. In any slot, the sensor node is in one of two modes: Wake or Sleep. The generated energy is stored in a buffer. The sensor node senses a random field and generates a packet when it is awake. These packets are stored in a queue and transmitted in the wake mode using the energy available in the energy buffer. We obtain energy management policies...
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