Fafoutis, Xenofon

Denne afhandling fokuserer på energieffektiv kommunikation i trådløse sensornetværk (eng. Wireless Sensor Networks), der er drevet af energi høstet fra omgivelserne. Afhandlingen beskriver energieffektive forbindelser mellem sendere og modtagere, der periodisk skifter mellem aktiv og sovende tilstande. Der er særlig fokus på Medium Access Control (MAC) protokoller, der følger det modtager-initieret paradigme med asynkron kommunikation. Ifølge dette paradigme initieres kommunikationen af modtageren gennem udsendelse af beacons, der udtrykker modtagerens tilgængelighed til at modtage data. Afsenderen lytter passivt til kanalen, indtil den modtager et beacon af interesse.I denne sammenhæng begynder afhandlingen med en grundig undersøgelse af alle modtager-initierede MAC-protokoller og præsenterer deres unikke optimerings funktioner. Disse funktioner beskæftiger sig med flere udfordringer i linket lag, såsom minimering af energiforbruget, undgåelse af kollisioner, tilvejebringelse af Qualityof-Service (QoS) og sikkerhed. Med fokus på de særlige krav der stilles til applikation baseret på energi høstning, fortsætter afhandlingen med en præsentation af en ny MACprotokol, kaldet ODMAC, som udbygger det modtager-initierede paradigme med flere energieffektive funktioner, der har til formål at tilpasse den forbrugte energi med den høstede energi, at distribuere belastningen med hensyn til den høstede energi, at mindske overhead af kommunikationen, at undgå kollisioner, at prioritere prioriteret trafik og at sikre systemet mod beacon replay angreb.Performance og opførsel af ODMAC og dens funktioner, sammenlignes med state - of- the-art og evalueres ved hjælp af matematiske modeller, simuleringer og eksperimenter, der er baseret på den trådløse platform eZ430-rf2500. Resultaterne fra disse eksperimenter, validerer en effektiv udnyttelse af den høstede energi og demonstrerer bæredygtig drift.Focusing on Wireless Sensor Networks (WSN) that are powered by energy harvesting, this dissertation focuses on energy-efficient communication links between senders and receivers that are alternating between active and sleeping states of operation. In particular, the focus lies on Medium Access Control (MAC) protocols that are following the receiver-initiated paradigm of asynchronous communication. According to the receiver-initiated paradigm the communication is initiated by the receiver that states its availability to receive data through beacons. The sender is passively listening to the channel until it receives the beacon of interest.In this context, the dissertation begins with an in-depth survey of all the receiverinitiated MAC protocols and presents their unique optimization features, which deal with several challenges of the link layer such as mitigation of the energy consumption, collision avoidance, provision of Quality of Service (QoS) and security. Focusing on the particular requirements of an energy harvesting application, the dissertation continues with the presentation of a MAC protocol, named ODMAC, which extends the receiver-initiated paradigm with several energy-efficient features that aim to adapt the consumed energy to match the harvested energy, distribute the load with respect to the harvested energy, decrease the overhead of the communication, address the requirements for collision avoidance, prioritize urgent traffic and secure the system against beacon replay attacks.The performance and behavior of ODMAC and its features are compared to the stateof-the-art and evaluated using mathematical models, simulations and testbed experiments that are based on eZ430-rf2500 wireless development platform. The results validate the efficient use of the harvested energy and demonstrate sustainable operation

Online Research Database In Technology

Medium Access Control in Energy Harvesting - Wireless Sensor Networks

http://orbit.dtu.dk/ws/files/93717745/phd328_Fafoutis_X.pdf

Medium Access Control in Energy Harvesting - Wireless Sensor Networks

Abstract

Similar works

Full text

Available Versions

Online Research Database In Technology