The baseband part of IEEE 802.15.4 operated in 2.45 GHz mode is designed and implemented in this essay. First, the features of IEEE 802.15.4 WPAN(Wireless Personal Area Network), PHY layer and MAC Layer are introduced. Then the algorithm and VHDL of the baseband part of transceiver are designed and verified by FPGA board and logical analyzer.

The main goals of diploma thesis are application and realization of tool for projection and installation wireless networks according to IEEE802.15.4. The thesis is specialized in construction of transmitter and receiver device in term of mobility and visualization of data measured in terrain. Than the software support for measuring and control appropriate periphery are summarised and described. The system is defined in C programming language and uses OpenMAC library. Last part of thesis is focus on practical measurement and testing tool for projection and installation wireless network.

This thesis deals with the issue of localization in wireless sensor networks. It focuses on the implementation Anchor-Free localization techniques to NS2 and evaluation of its effectiveness. In the theoretical introduction is summarized IEEE802.15.4 and ZigBee technology. The following chapter describes the Anchor-Based and Anchor-Free localization methods. Furthermore, existing methods of measuring the distance of network nodes are described. Also pay attention NS2 environment, especially the inclusion of standard IEEE802.15.4. The section devoted to Anchor-Free algorithm describes how to search and select anchor modes. It also described the method of optimization by measuring the distance of neighboring nodes using the Mass-Spring Algorithm. Next chapter describe the inclusion of a new protocol called AFLOCAL into NS2 and detailed analysis of its function. Next described the process of localization and calculating the coordinates. Described was aslo a method of simulation and evaluation of results. In conclusion, the results are summarized and formulated the characteristics of designed protocol AFLOCAL.

Táto práca sa venuje probému prepojovania rôznych typov sietí, konkrétne sietí typu IEEE 802.15.4 a Ethernetu. Motivácia vychádza zo stále sa rozširujúceho využitia bezdrátových senzorických sietí, potreby zberu dát z nich a ich integrácie. To vyžaduje aby sieť obsahovala prvky schopné preniesť dáta z bezdrátovej siete do okolitého sveta a prípadne poskytnúť konfiguračné a riadiace informácie do vnútra siete. Z hľadiska protokolov a programového vybavenia sa prepojenie uskutočňuje na rôznej úrovni, od sieťovej až po aplikačnú vrstvu komunikačného modelu ISO/OSI, s podporou hardvéru na fyzickej a linkovej vrstve.

Master of Science / Department of Electrical and Computer Engineering / William B. Kuhn / Wireless Sensor Network industrial and civilian applications have been moved closer to us since they were originally developed for defense applications. They have been or will be widely used in industrial process monitoring and control, earth quake monitoring, healthcare applications, construction health monitoring, home automation, traffic control, and space exploration. The IEEE802.15.4 standard defines the PHY and MAC layers for low power wireless sensor networks. However, applications and research of wireless sensor networking are centered on battery powered devices. To remove the battery from the system is the ultimate goal of this research by using Energy Harvesting technology, which will largely reduce the wireless sensor network maintenance cost, increase the option open to application environments and push the speed of wireless sensor network industrialization. This thesis tackles the problem of RF link budget and PHY layer design for Energy Harvesting Wireless Sensor Network Nodes, through a modification to PHY/MAC layers. To this end, a prototype of energy harvesting radio is developed that hinges on burst-communication and solar cell energy harvesting techniques. The choice of operating frequency is considered relative to transmission range, antenna technology and RF link budget, and quantified by propagation measurements at four unlicensed frequencies in the VHF through UHF spectrums. A short preamble, PHY payload protocol frame structure and synchronization method are also proposed in order to support long sleep period duty cycle necessary in Energy Harvesting Radio systems. Some related work has recently begun under a standardization effort known as 802.15.4f. It is hoped that this thesis will contribute to this effort.

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This thesis focuses on design of wireless network nodes using modular construction parts with respect to IEEEŽ 802.15.4 standard. Presented platform joins the benefits of the XBeeŽ wireless module and the AVR ATmega128 microcontroller development system. Sensor network prototype is designed to meet the desired first attempt functionality of embedded platform for collection and delivery of small volumes of control and sensor data between the network and the gateway. The control software was developed for TinyOS operating system. Designed platform is used as the framework for future development and possible functionality extensions in related applications.

The Internet of Things (IoT) is widely adopted across various fields due to its flexibility and low cost. Energy-harvesting Wireless Sensor Networks (WSNs) are becoming a building block of many IoT applications and provide a perpetual source of energy to power energy-constrained IoT devices. However, the dynamic and stochastic nature of the available harvested energy drives the need for adaptive energy management solutions. Duty cycling is among the most prominent adaptive approaches that help consolidate the effort of energy management solutions at the routing and application layers to ensure energy sustainability and, hence, continuous network operation.  The IEEE 802.15.4 standard defines the physical layer and the Medium Access Control (MAC) sub-layer of low-data-rate wireless devices with limited energy consumption requirements. The MAC sub-layer’s functionalities include the scheduling of the duty cycle of individual devices. However, the scheduling of the duty cycle is left open to the industry. Various computational mechanisms are used to compute the duty cycle of IoT nodes to ensure optimal performance in energy sustainability and Quality of Service (QoS). Reinforcement Learning (RL) is the most employed mechanism in this context.  The literature depicts various RL-based solutions to adjust the duty cycle of IoT devices to adapt to changes in the IoT environment. However, these solutions are usually tailored to specific scenarios or focus mainly on one aspect of the problem, namely QoS performance or energy limitation. This work proposes a generic adaptive duty cycling solution and evaluates its performance under different energy generation and traffic conditions. Moreover, it emphasizes the energy sustainability aspect while taking the QoS performance into account.  While different approaches exist to achieve energy sustainability, Energy Neutral Operation (ENO)-based solutions provide the most prominent approach to ensure energy-sustainable performance. Nevertheless, these approaches do not necessarily guarantee optimal performance in QoS. This work adopts a Markov Decision Process (MDP) model from the literature that aims to minimize the distance from energy neutrality given the energy harvesting and ENO conditions. We introduce QoS penalties to the reward formulation to improve QoS performance.  We start by examining the performance in QoS against the benchmarking solution. Then, we analyze the performance using different energy harvesting and consumption profiles to further assess QoS performance and determine if energy sustainability is still maintained under different conditions. The results prove more efficient utilization of harvested energy when available in abundance. However, one limitation to our solution occurs when energy demand is high, or harvested energy is scarce. In such cases, we observe degradation in QoS due to IoT nodes adopting a low-duty cycle to avoid energy depletion. We further study the effect this limitation has on the solution's scalability. We also attempt to address this problem by assessing the performance using a routing solution that balances load distribution and, hence, energy demand across the network.

The work focuses on introduction to the topic of wireless sensor networks and brings readers the various aspects of problem solving in these networks. Work is closely focused on the energy performance when communicating between devices on a network and discusses the causes of excessive energy consumption. It also addresses the mechanisms for saving energy and is also engaged today protocols that its contribution to proposing solutions to problems. The author had also proposes an adapted protocol, based on lessons learned from previous theoretical sources.