An Energy Balanced Dynamic Topology Control Algorithm for Improved Network Lifetime

In wireless sensor networks, a few sensor nodes end up being vulnerable to potentially rapid depletion of the battery reserves due to either their central location or just the traffic patterns generated by the application. Traditional energy management strategies, such as those which use topology control algorithms, reduce the energy consumed at each node to the minimum necessary. In this paper, we use a different approach that balances the energy consumption at each of the nodes, thus increasing the functional lifetime of the network. We propose a new distributed dynamic topology control algorithm called Energy Balanced Topology Control (EBTC) which considers the actual energy consumed for each transmission and reception to achieve the goal of an increased functional lifetime. We analyze the algorithm's computational and communication complexity and show that it is equivalent or lower in complexity to other dynamic topology control algorithms. Using an empirical model of energy consumption, we show that the EBTC algorithm increases the lifetime of a wireless sensor network by over 40% compared to the best of previously known algorithms

A Comprehensive Survey of Potential Game Approaches to Wireless Networks

Potential games form a class of non-cooperative games where unilateral improvement dynamics are guaranteed to converge in many practical cases. The potential game approach has been applied to a wide range of wireless network problems, particularly to a variety of channel assignment problems. In this paper, the properties of potential games are introduced, and games in wireless networks that have been proven to be potential games are comprehensively discussed.Comment: 44 pages, 6 figures, to appear in IEICE Transactions on Communications, vol. E98-B, no. 9, Sept. 201

An Overview of Distributed Energy-Efficient Topology Control for Wireless Ad Hoc Networks

A wireless ad hoc network is composed of several tiny and inexpensive device such as wireless sensor networks (WSNs) which have limited energy. In this network energy, efficiency is one of the most crucial requirements. Data transmitting in minimum power level is one way of maximizing energy efficiency. Thus, transmission power level of nodes should be managed in a smart way to improve energy efficiency. Topology control is one of the main algorithms used in a wireless network to decrease transmission power level while preserving network connectivity. Topology control could improve energy efficiency by reasonably tuning the transmission power level while preserving network connectivity in order to increase network capacity and lifetime. In pursuit of energy efficiency and connectivity, nodes can be selfish and are conflicting with each other. Therefore to overcome the conflict, game theory is used to construct energy efficient topology, as well as minimizing energy consumption. In this paper, the main goal and most recent energy efficient topology control algorithms in WSNs and ad hoc network are classified and studied according to their specific goals

Towards Energy - Efficient Qos-Aware Online Stream Data Processing for Internet of Things

Online data stream processing in Internet of Things (IoT) systems is an emerging paradigm that allows users to use resource-constrained IoT devices with the back- end of resourceful machines to process the data collected from the physical world in a real-time manner. The huge amount of generated sensor data can produce value- added information with different purposes for several applications. Techniques to pro- mote knowledge discovery from the raw data allow fully exploiting the potential usage of wide spread sensors in the IoT. In this context, using the energy of the resource- constrained IoT devices in an efficient way is a major concern. However, the appli- cation of QoS requirements should not be ignored to achieve the purpose of energy saving at any cost. In this thesis, we propose a framework that combines online stream data processing with adaptive system control to address both needs. The online algo- rithms are based on statistical methods to meet the needs of stream data processing. The result of the algorithms are then used to dynamically control the system behaviour to meet the needs of energy-saving. Simulation results show the effectiveness of our proposed framework

Wake-up communication system using solar panel and visible light communication

[ANGLÈS] One of the most promising energy-efficient communication methods is the use of wake-up receivers. In this work we propose and develop a wake-up communication system that uses Visible Light Communication (VLC) and an indoor solar panel with two functions: act as the receiver of the wake-up signal and harvest power from the light. After the reception of the wake-up signal an interrupt generated by the wake-up receiver wakes up the wireless device attached. Two configuration options are presented: an addressable and a broadcast-based wake-up configuration. In addressable configuration, after the reception of the wake-up signal a comparison is made with the identification code configured in the device; as consequence only the device with the match code is woken up. In broadcast-based wake-up configuration the wireless node attached wakes up after the detection of the carrier burst frequency, allowing use this system for wake up several nodes at once. Two options of configuration for the receiver are presented, and also the design of a transmitter who copes with flickering mitigation. Through experiments the feasibility of the system is shown and its performances is characterized in terms of wake-up probabilities for different distances. The effect of light interferences is evaluated, which shows that the achieved wake-up distances are reasonable for indoor scenarios.[CASTELLÀ] Uno de los más prometedores métodos para la comunicación con mayor eficiencia energética en las Redes de Sensores Inalámbricos (Wireless Sensor Networks - WSN) es el uso de wake-up receivers. Es este trabajo se propone y desarrolla un sistema de comunicación de wake-up que usa las comunicaciones por luz visible (Visible Light Communication - VLC) y un panel solar de interiores con dos funciones: actuar como receptor de la señal de wake-up y recoger energía de la luz. Después de la recepción de la señal el wake-up receiver genera una interrupción activando el nodo inalámbrico adjunto. Se presentan dos configuraciones para la generación de la interrupción: una basada en dirección y otra basada en la transmisión de la frecuencia portadora. En la configuración basada en dirección, después de la recepción de la señal de wake-up se hace una comparación con el código de identificación configurado en el dispositivo; como consecuencia sólo el dispositivo con el código correcto es activado. En la configuración basada en la transmisión de la frecuencia portadora, el nodo inalámbrico adjunto se activa con la detección de dicha frecuencia, lo cual permite usar el sistema para activar varios nodos a la vez. Se describen dos opciones de configuración para el receptor, así como el diseño de un transmisor diseñado para mitigar el parpadeo del LED. A través de experimentos se muestra la factibilidad del sistema y se caracteriza su desempeño en términos de la probabilidad de generar la interrupción de activación a diferentes distancias entre la fuente de luz y el receptor. Se evalúa el efecto de las interferencias de luz y se muestra que las distancias alcanzadas son razonables para escenarios intramuros.[CATALÀ] Un dels mètodes més prometedors per a la comunicació amb una major eficiència energètica en les Xarxes de Sensors Sense fil (Wireless Sensor Networks - WSN) és l'ús de wake-up receivers en el node receptor. Els wake-up receivers són dispositius d'ultra-baix consum de potència connectats al node sense fil que li permeten romandre en estat inactiu mentre esperen un senyal d'activació. En aquest treball es proposa i desenvolupa un sistema d’activació que usa les comunicacions per llum visible (Visible Light Communication - VLC) i un panell solar d’ús interior amb dues funcions: actuar com a receptor del senyal d’activació i recollir energia de la llum ambient. Després de la recepció del senyal de l’emissor, el wake-up receiver genera una interrupció activant el node sense fil adjunt. Es descriuen dues alternatives per a la generació de la interrupció: una basada en identificador i una altra basada en la transmissió de la freqüència portadora. En la configuració basada en identificador, després de la recepció del senyal de wake-up es fa una comparació amb el codi d'identificació al dispositiu i, com a conseqüència, només el dispositiu amb el codi correcte és activat. En la configuració basada en la transmissió de la freqüència portadora, el node sense fil adjunt s'activa amb la detecció d'aquesta freqüència, la qual cosa permet utilitzar el sistema per activar diversos nodes alhora. També se detallen dues opcions de configuració per al receptor així com el disseny d'un transmissor per mitigar el parpelleig del LED. Mitjançant experiments es mostra la factibilitat del sistema i s’avalua el seu funcionament en termes de la probabilitat de generar la interrupció d'activació a diferents distàncies entre la font de llum i el receptor. S'avalua l'efecte de les interferències del senyal i es mostra que les distàncies assolides són raonables per escenaris en interiors

Energy-aware Approaches for Energy Harvesting Powered Wireless Sensor Systems

Energy harvesting (EH) powered wireless sensor systems (WSSs) are gaining increasing popularity since they enable the system to be self-powering, long-lasting, almost maintenance-free, and environmentally friendly. However, the mismatch between energy generated by harvesters and energy demanded by WSS to perform the required tasks is always a bottleneck as the ambient environmental energy is limited, and the WSS is power hunger. Therefore, the thesis has proposed, designed, implemented, and tested the energy-aware approaches for wireless sensor motes (WSMs) and wireless sensor networks (WSNs), including hardware energy-aware interface (EAI), software EAI, sensing EAI and network energy-aware approaches to address this mismatch. The main contributions of this thesis to the research community are designing the energy-aware approaches for EH Powered WSMs and WSNs which enables a >30 times reduction in sleep power consumption of WSNs for successful EH powering WSNs without a start-up issue in the condition of mismatch between the energy generated by harvesters and energy demanded by WSSs in both mote and network systems. For EH powered WSM systems, the energy-aware approaches have (1) enabled the harvested energy to be accumulated in energy storage devices to deal with the mismatch for the operation of the WSMs without the start-up issue, (2) enabled a commercial available WSMs with a reduced sleep current from 28.3 μA to 0.95 μA for the developed WSM, (3) thus enabled the WSM operations for a long active time of about 1.15 s in every 7.79 s to sample and transmit a large number of data (e.g., 388 bytes), rather than a few ten milliseconds and a few bytes. For EH powered WSN systems, on top of energy-aware approached for EH powered WSM, the network energy-aware approaches have presented additional capabilities for network joining process for energy-saving and enabled EH powered WSNs. Once the EH powered WSM with the network energy-aware approach is powered up and began the network joining process, energy, as an example of 48.23 mJ for a tested case, has been saved in the case of the attempt to join the network unsuccessfully. Once the EH-WSM has joined the network successfully, the smart programme applications that incorporate the software EAI, sensing EAI and hardware EAI allow the EH powered WSM to achieve (4) asynchronous operation or (5) synchronised operation based on the energy available after the WSM has joined the network.Through designs, implementations, and analyses, it has been shown that the developed energy-aware approaches have provided an enabled capability for EH successfully powering WSS technologies in the condition of energy mismatch, and it has the potential to be used for wide industrial applications

Distributed algorithms for extending the functional lifetime of wireless sensor networks

The functional lifetime of a wireless sensor network (WSN) is among its most important features and serves as an essential metric in the evaluation of its energy-conserving policies. Approaches for extending the lifetime of a wireless sensor node include using an on/off strategy on the sensor nodes and using a topology control algorithm on each node to regulate its transmission power. However, the need to keep the network functional imposes certain additional constraints on strategies for energy conservation. A sensing constraint imposes that the sensing tasks essential to the functionality of the WSN are not compromised. A communication constraint similarly imposes that communications essential to an application on the network remain possible even as battery resources deplete on the nodes. This dissertation presents new distributed algorithms for energy conservation under these two classes of constraints: sensing constraints and communication constraints. One sensing constraint, called the representation constraint in this dissertation, is the requirement that active (on) sensor nodes are evenly distributed in the region of interest covered by the sensor network. This dissertation develops two essential metrics which together allow a rigorous quantitative assessment of the quality of representation achieved by a WSN and presents analytical results which bound these metrics in the common scenario of a planar region of arbitrary shape covered by a sensor network deployment. The dissertation further proposes a new distributed algorithm for energy conservation under the representation constraint. Simulation results show that the proposed algorithm is able to significantly improve the quality of representation compared to other related distributed algorithms. It also shows that improved spatial uniformity has the welcome side-effect of a significant increase in the functional lifetime of a WSN. One communication constraint, called the connectivity constraint, imposes that the network remains connected during its functional life. The connectivity required may be weak (allowing unidirectional communication between nodes) or strong (requiring bidirectional link layer communication between each pair of communicating nodes). This dissertation develops new distributed topology control algorithms for energy conservation under both the strong and the weak connectivity constraint. The proposed algorithm for the more ideal scenario of the weak connectivity constraint uses a game-theoretic approach. The dissertation proves the existence of a Nash equilibrium for the game and computes the associated price of anarchy. Simulation results show that the algorithms extend the network lifetime beyond those achieved by previously known algorithms.Ph.D., Computer engineering -- Drexel University, 201