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Title: Prioritised and adaptive preamble sampling MAC protocols for Wireless Sensor Networks
Author: Choobkar, Sabrieh
ISNI:       0000 0004 5368 4127
Awarding Body: King's College London
Current Institution: King's College London (University of London)
Date of Award: 2015
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A Wireless Sensor Network (WSN) is composed of many sensor nodes that gather measurements from the environment and transmit them to a central unit for analysis. Sensor nodes are small devices with limited energy resources. Therefore, energy is a crucial concept in a WSN. Optimised design of medium access control (MAC) protocol results in efficient energy consumption while improves delay, lifetime and reliability of data delivery. Our research considers a network with a contention-based MAC protocol. The contributions of this thesis are divided into two parts: • We analyse the concept of priority in a WSN and consider setting high priority to a special node based on the application requirements. Firstly, we assign higher priority to nodes that are running out of energy in order to reduce their activity (less transmition and reception than before) and force the low priority nodes to be more active. Our energy management approach tries to balance energy consumption in a neighbourhood and presents energy saving of around 10% which leads to lifetime expansion of the prioritised network. Secondly, in some other applications we set higher priority to nodes that are more likely to generate significant data (such as kitchen node in a fire alarm system). The high priority nodes send data sooner than other nodes and reduce the contention delay. As a result, average delay for transmitting data in a prioritised network is less compared to an equal-priority nodes network (25% for traffics of 0.3 to 0.7 sample/frame ). We extend the idea of Receiver-Based MAC protocol (RB-MAC) to propose two adaptive preamble sampling techniques, named as adaptive preamble (ap-MAC) and adaptive sampling (as-MAC) protocols. They introduce cross-layer approaches in which routing decisions can be made based on MAC layer functionalities. We study the effects of multiple receiver nodes, size of preamble and variable duty-cycle on number of data retransmissions in both single-hop and multi-hop data forwarding. The analytical and numerical results demonstrate the applicability of the derived protocols in addition to energy efficiency, while maintaining comparable reliability in data delivery.
Supervisor: Aghvami, Abdol-Hamid ; Shams Dilmaghani, Reza Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available