Date of Award

2011

Document Type

Doctoral Thesis

Degree Name

Doctor of Philosophy

Department

Electronic Engineering

First Advisor

Dr Dirk Pesch

Abstract

A wireless sensor network (WSN) is a network of sensor nodes that functions in a cooperative manner to monitor the changes in the physical environment. Typically, sensor nodes are deployed in places with difficult access, if any, to an external power supply thus requiring battery power. Therefore, WSN communication protocols must be designed with energy efficient and self-organizing capabilities in mind. In this context, the IEEE 802.15.4 standard is being widely employed for the lower layers of low-cost, low-rate and low-power wireless sensor communications due to its potential to fulfil requirements of various monitoring and control applications. However, the specification does not suggest any algorithms to adapt the IEEE 802.15.4 protocol parameters, but it requires manual configuration by the system designer in order to provide optimal performance. This thesis presents an energy aware communications (EAC) framework for IEEE 802.15.4 beacon-enabled WSNs that configures the standard communication parameters during run time, without the need for human intervention, with the aim of providing energy efficiency while fulfilling application requirements. This presents the advantage of greatly reducing the total time and cost of WSN deployment, operation and management. The proposed EAC framework embraces a set of algorithms that mainly adapt duty cycle, link and contention parameters according to the feedback obtained from the network in order to select the protocol configuration that minimises the total power consumption. Additionally, the EAC framework in­cludes distributed time scheduling and duty cycle management algorithms that are used when multi-hop mesh operation is needed to facilitate large scale WSN deployments. A performance evaluation carried out in a physical test-bed, computer emulation, and simulation of IEEE 802.15.4 compliant sensor nodes show that the proposed EAC framework is able to self-adapt the communication protocol parameters and enable energy efficient multi-path mesh networking in IEEE 802.15.4 beacon-enabled WSNs.

Access Level

info:eu-repo/semantics/openAccess

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Physics Commons

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