The master’s thesis deals with development of the radio channel analyser operating in the unlicensed 2.4 GHz band according to IEEE 802.15.4 standard. The analyzer will contain two basic functions, namely energy detection of channels and analysation of selected channel. Detection of energy will be solved by selection between simple graph and text list on display. Based on information about the occupancy of channels the user can decide which channel would be set up. During the receiving of valid frame the source address, signal strength and signal quality will be stored. At the end the processor will show these data on display. For controlling the device will be installed two LEDs and four buttons.

Wireless Sensor Networks are the main representative of pervasive computing in large-scale physical environments. These networks consist of a large number of small, wireless devices embedded in the physical world to be used for surveillance, environmental monitoring or other data capture, processing and transfer applications. Ultra wideband has emerged as one of the newest and most promising concepts for wireless technology. Considering all its advantages it seems a likely communication technology candidate for future wireless sensor networks. This paper considers the viability of ultra wideband technology in wireless sensor networks by employing an IEEE 802.15.4a low-rate ultra wideband physical layer model in the OMNET++ simulation environment. An elaborate investigation into the inner workings of the IEEE 802.15.4a UWB physical layer is performed. Simulation experiments are used to provide a detailed analysis of the performance of the IEEE 802.15.4a UWB physical layer over several communication distances. A proposal for a cognitive, adaptive communication approach to optimize for speed and distance is also presented. AFRIKAANS : Draadlose Sensor Netwerke is die hoof verteenwoordiger vir deurdringende rekenarisering in groot skaal fisiese omgewings. Hierdie tipe netwerke bestaan uit ’n groot aantal klein, draadlose apparate wat in die fisiese wêreld ingesluit word vir die doel van bewaking, omgewings monitering en vele ander data opvang, verwerk en oordrag applikasies. Ultra wyeband het opgestaan as een van die nuutste en mees belowend konsepte vir draadlose kommunikasie tegnologie. As al die voordele van dié kommunikasie tegnologie in ag geneem word, blyk dit om ’n baie goeie kandidaat te wees vir gebruik in toekomstige draadlose sensor netwerke. Hierdie verhandeling oorweeg die vatbaarheid van die gebruik van die ultra wyeband tegnologie in draadlose sensor netwerke deur ’n IEEE 802.15.4a lae-tempo ultra wyeband fisiese laag model in die OMNET++ simulasie omgewing toe te pas. ’n Breedvoerige ondersoek word geloots om die fyn binneste werking van die IEEE 802.15.4a UWB fisiese laag te verstaan. Simulasie eksperimente word gebruik om ’n meer gedetaileerde analiese omtrent die werkverrigting van die IEEE 802.15.4a UWB fisiese laag te verkry oor verskillende kommunikasie afstande. ’n Voorstel vir ’n omgewings bewuste, aanpasbare kommunikasie tegniek word bespreek met die doel om die spoed en afstand van kommunikasie te optimiseer. / Dissertation (MEng)--University of Pretoria, 2011. / Electrical, Electronic and Computer Engineering / unrestricted

The development of new energy efficient Wireless Personal Area Network (WPAN) protocols is a big factor for the increased interest in Internet of Things (IoT). However, the many protocols with overlapping applications have led to competing standards and sensor networks using different protocols, even to perform the same tasks. If different sensors in IoT uses different protocols in the same area, a single gateway connecting to all of them must support all their protocols simultaneously. This thesis studies latency, average sending time and range for Bluetooth Low Energy (BLE), 802.15.4 and Zigbee in multiprotocol mode on the nRF52840 System on Chip (SoC). In addition, an 802.15.4-based protocol synchronizing with the BLE frames using Time Division Multiple Access (TDMA) techniques was designed and implemented. This protocol could be used in sensor networks using both the BLE and 802.15.4 protocols to assure the 802.15.4-based devices will not try to transmit during the periods the gateway is busy with other communications. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

A wireless sensor network consists of small, limited-resource embedded systems exchanging environment data and activating controls. These networks can be deployed in hostile environments to monitor wildlife habitats, implemented in factories to locate mobile equipment, and installed in home environments to optimize the use of utilities. Each of these scenarios requires network security to protect the network data. The IEEE 802.15.4 standard is designed for WSN communication, yet the standard states that it is not responsible for defining the initialization, distribution, updating, or management of network public keys. Individuals seeking to research security topics will find that there are many 802.15.4-compliant development hardware kits available to purchase. However, these kits are not easily compared to each other without first-hand experience. Further, not all available kits are suitable for research in WSN security. This thesis evaluates a broad spectrum of 802.15.4 development kits for security studies. Three promising kits are examined in detail: Crossbow MICAz, Freescale MC1321x, and the Sun SPOT. These kits are evaluated based on their hardware, software, development environment, additional libraries, additional tools, and cost. Recommendations are made to security researchers advising which kits to use depending on their design needs and priorities. Suggestions are made to each company on how to further improve their kits for security research.

As wireless protocols become easier to implement, more products come with wireless connectivity. This latest push for wireless connectivity has left a gap in the development of the security and the reliability of some protocols. These wireless protocols can be used in the growing field of IoT where wireless sensors are used to share information throughout a network. IoT is being implemented in homes, agriculture, manufactory, and in the medical field. Disrupting a wireless device from proper communication could potentially result in production loss, security issues, and bodily harm. The 802.15.4/ZigBee protocol is used in low power, low data rate, and low cost wireless applications such as medical devices and home automation devices. This protocol uses CSMA-CA (Carrier Sense Multiple Access w/ Collision Avoidance) which allows for multiple ZigBee devices to transmit simultaneousness and allows for wireless coexistence with the existing protocols at the same frequency band. The CSMA-CA MAC layer seems to introduce an unintentional gap in the reliability of the protocol. By creating a 16-tone signal with center frequencies located in the center of the multiple access channels, all channels will appear to be in use and the ZigBee device will be unable to transmit data. The jamming device will be created using the following hardware implementation. An FPGA connected to a high-speed Digital to Analog Converter will be used to create a digital signal synthesizer device that will create the 16-tone signal. The 16-tone signal will then be mixed up to the 2.4 GHz band, amplified, and radiated using a 2.4 GHz up-converter device. The transmitted jamming signal will cause the ZigBee MAC layer to wait indefinitely for the channel to clear. Since the channel will not clear, the MAC layer will not allow any transmission and the ZigBee devices will not communicate.

The need for energy efficiency in wireless communication is prevalent in all areas, but to an even greater extent in low-power and lossy networks that rely on resource-constrained devices. This degree project seeks to address the problem of modelling the battery lifetime of a duty-cycled node, participating in a wireless sensor network that is typically used in smart home and building applications. Modelling in MATLAB combined with experimentation are employed to predict the life expectancy and to validate using a hardware implementation. Various scenarios including sleepy end devices in a wireless sensor network are modelled and validated; these range from variable wake-up frequency and packet payload transmission to increasing network contention with the addition of network load. A comprehensive analysis of the main factors contributing to wasteful energy usage is provided in this thesis project, and it can be concluded that the model can estimate the battery lifetime under different testing scenarios with an error less than 5 %. / Det finns ett stort behov av energieffektivitet inom trådlös kommunikation, särskilt inom nätverk med bortfall och låg strömförbrukning där resursbegränsade enheter nyttjas. Det här examensarbetet eftersträvar att lösa problemet med att modellera batterilivslängden hos en sensoranordning med en låg driftcykel, som en del av ett trådlöst sensornätverk avsett för att tillämpas i smarta hus och byggnader. Modellering i MATLAB kombinerat med experimentering används för att förutsäga den förväntade livslängden samt för att validera en hårdvaruimplementering. Flertalet scenarier med sovande noder modelleras och valideras, med allt från variabel uppvakningsfrekvens och paketöverföring till ökande resurskonflikter med ytterligare belastning på nätverket. I detta examensprojekt inkluderas en heltäckande analys av huvudorsakerna till energislöseriet hos enheterna och slutsatsen kan dras att modellen kan beräkna batterilivslängden för olika testscenarier med mindre än 5 % fel.

The master thesis is a prototyping project of a wireless body area network (WBANs) for patient monitoring in hospitals. The goal of this project was to study various technologies suitable for wireless body area networks, complete a requirement analysis, design a WBAN suitable to achieve the requirements and to test and evaluate the system against the requirements. Seven sensor end nodes are chosen to monitor seven vital signs for patient monitoring. After studying different technologies suitable for WBANs, IEEE 802.15.4j was chosen because it communicates in a special allocation of medical spectrum of 2360 to 2400MHz. A coordinator or master will be the center of the network using a star topology. Due to certain limitations in the firmware of the NXP FRDMKW40Z, IEEE 802.15.4j had to be dropped and IEEE 802.15.4 was the final chosen technology because the only difference between IEEE 802.15.4j and IEEE802.15.4 is the difference in the physical layer, while the developed application remains the same, making the shift back to IEEE802.15.4j, in the future, simple. There have been several projects working on the same idea with IEEE 802.15.4, but they do not combine multiple sensors to form a network and the total throughput requirements for this thesis project are much higher. The beacon mode and the non-beacon mode of IEEE 802.15.4 are studied. Non beacon mode is unpredictable due to the use of carrier sense multiple access with collision avoidance (CSMA/CA) to access the medium. When multiple end nodes compete to get access to the medium, unreliability is introduced into the system. In the beacon mode, because of the slotted CSMA access of sixteen equally spaced time slots for communication, there is a restriction of the size of a time slot and thus, the high throughput requirement of the system is not met. The solution proposed in the thesis project is to develop a custom time slot system in the non-beacon mode, where each end node is granted a reserved time slot of a specific length as required by the end node. There is a timer mechanism which makes sure that the time slots for each device maintain the time limit on the time slot, on the side of the main master/coordinator of the network and on the side of the end node. The protocol for an end node to join a personal area network (PAN) is called as the association process. The association process enables the end node to be a part of a PAN to exchange its sensor data. Traditionally, in IEEE 802.15.4, the end nodes scan the sixteen IEEE 802.15.4 channels and when an appropriate coordinator is found, the end node initiates the association process with the coordinator. The solution proposed for the formation of the network by the association process is to use two different technologies. The end nodes and the coordinator exchange information using near field communication (NFC) technology by a simple tapping mechanism. The end node has an active NFC tag while the coordinator has an NFC reader. During the tap between the two devices, first the coordinator reads the end node data from the active tag. This data is required to form the custom time slot. Next the coordinator writes all association information into the active tag. After the NFC data exchange is done, the end node initiates the traditional IEEE 802.15.4 association protocol to join the coordinator’s PAN. Similarly after seven end nodes are associated to the coordinator, the network begins to function. All the end nodes communicate their data to the coordinator. The coordinator collects all the sensor data from the seven end nodes and may send the cumulative sensor data to the backend database servers which may be viewed by the medical authorities, this part is not included in the current version of the project. Several tests are run on this system to evaluate the requirements of latency, throughput and quality of service with two different ranges of 20cm and 250cm. The latency of association between the coordinator and end node is 632ms. The required throughput is met by the network. The packet delivery rate of the system is always above 99%. The graphs for packet delivery rates for all the sensors with a range of 20cm and 250 cm are shown in the appendices. The probabilities for the packet delivery rates greater than 90%, 99%, 99.9% and 99.99% are also graphically shown using a normal distribution in the appendices.

Τα ασύρματα δίκτυα αισθητήρων αποτελούν μία πρωτοποριακή τεχνολογία που ήρθε στο προσκήνιο πριν από μία περίπου δεκαετία. Η καινοτομία της τεχνολογίας αυτής έγκειται στη συνεργασία μεγάλου αριθμού κόμβων περιορισμένων πόρων χαμηλής κατανάλωσης ισχύος σε μία μόνο εφαρμογή. Η εργασία αυτή ασχολείται με θέματα ενδιάμεσου λογισμικού σε ασύρματα δίκτυα αισθητήρων. Συγκεκριμένα, μελετάται το πρωτόκολλο Deluge που αποτελεί τη βασική επιλογή για ασύρματο προγραμματισμό δικτύων αισθητήρων που «τρέχουν» το λειτουργικό σύστημα πραγματικού χρόνου TinyOS. Παρέχοντας έναν αξιόπιστο και αποδοτικό μηχανισμό διάδοσης δεδομένων μέσω της δυαδικής εικόνας του κώδικα, το Deluge κατέχει ρόλο-κλειδί στη βαθμίδα ενδιάμεσου λογισμικού των ασύρματων δικτύων αισθητήρων. Η μελέτη και κατανόηση του πρωτοκόλλου αυτού επέτρεψε την υλοποίηση σε nesC ενός απλούστερου πρωτοκόλλου που αξιοποιεί τα βασικά χαρακτηριστικά του μηχανισμού μετάδοσης δεδομένων του Deluge. Σε συνέχεια αυτής της υλοποίησης, αξιολογήθηκε εκ νέου η διαδικασία μετάδοσης πραγματοποιώντας δοκιμές τόσο σε πραγματικές τοπολογίες κόμβων αισθητήρων (motes) που υποστηρίζουν το πρότυπο ασύρματης επικοινωνίας IEEE 802.15.4 όσο και σε περιβάλλον προσομοίωσης (TOSSIM). Τα προκύπτοντα αποτελέσματα επιβεβαιώνουν την αποδοτική μετάδοση δεδομένων σε δίκτυα αισθητήρων αξιοποιώντας το πρωτόκολλο Deluge. Η παρούσα εργασία αποτελείται από έξι κεφάλαια. Το πρώτο κεφάλαιο παρέχει πληροφορίες για το γνωστικό αντικείμενο της εργασίας. Στο δεύτερο κεφάλαιο παρουσιάζεται μία μελέτη στην ερευνητική περιοχή των ασύρματων δικτύων αισθητήρων και στο τρίτο κεφάλαιο εξετάζονται τα βασικά χαρακτηριστικά ενός κόμβου αισθητήρων που υποστηρίζει το πρότυπο IEEE 802.15.4. Στο τέταρτο κεφάλαιο παρουσιάζεται η έννοια του ασύρματου προγραμματισμού στα δίκτυα αισθητήρων και μελετάται εκτενώς το πρωτόκολλο Deluge. Στο πέμπτο κεφάλαιο περιγράφεται η υλοποίηση που έλαβε χώρα και η αξιολόγηση αυτής με τους μηχανισμούς που αναφέρθηκαν παραπάνω. Τέλος, στο έκτο κεφάλαιο παρατίθενται τα συμπεράσματα που εξήχθησαν από την εκπόνηση της εν λόγω εργασίας και δίνονται ορισμένες κατευθύνσεις για μελλοντική ενασχόληση με το Deluge και με το ενδιάμεσο λογισμικό στα δίκτυα αισθητήρων γενικότερα. / Wireless sensor networks (WSNs) emerged about a decade ago, representing a new class of computing with large numbers of resource-constrained computing nodes cooperating on a single application. This thesis deals with middleware issues in wireless sensor networks. Specifically, we study Deluge that suggests the de facto over-the-air programming protocol for WSNs working under TinyOS. Providing a reliable and efficient data dissemination mechanism via the binary image of the program code, Deluge plays a key role in the middleware layer of WSNs. Gaining insight into Deluge, we implemented in the nesC programming language a simplified protocol that incorporates the main features of Deluge data dissemination mechanism. This implementation allowed us to evaluate further the propagation procedure of Deluge using a two-mechanism evaluation framework. Carrying out experiments both in real-world deployments being compatible with IEEE 802.15.4 radio and in a simulation environment (TOSSIM), we verified the efficient data propagation in WSNs, using Deluge. This dissertation follows a structure of six chapters. In the first chapter, we give a piece of information about the subject field of this thesis. In the second chapter, we present an overall survey of the research area of WSNs and in the third chapter we examine the basic features of a sensor node (mote) whose wireless communication is based on an IEEE 802.15.4 compliant radio. In the fourth chapter, we discuss network programming in WSNs and we analyze the data dissemination mechanism of Deluge. In the fifth chapter, we discuss our implementation and its evaluation. Finally, in the sixth chapter, we conclude the thesis emphasizing the experience derived from that and we give some directions for future work with Deluge and middleware in WSNs generally.

Made available in DSpace on 2014-12-17T14:56:21Z (GMT). No. of bitstreams: 1 CarloFPSC.pdf: 941846 bytes, checksum: 5fe2e2c9851039018a0653de693d001c (MD5) Previous issue date: 2006-11-27 / Wireless sensor networks are reality nowadays. The growing necessity of connectivity between existing industrial plant equipments pushes the research and development of several technologies. The IEEE 802.15.4 LR-WPAN comes as a low-cost and powersaving viable solution, which are important concerns while making decisions on remote sensoring projects. This study intends to propose a wireless communication system which makes possible the monitoring of analogic and/or digital variables (i. e., the pressure studied) involved on the artificial methods for oil and gas lifting. The main issues are: To develop a software based on SMAC Standard in order to create a wireless network to monitoring analogic and/or digital variables; To evaluate the communication link based on the number of lost packets tested in different environments (indoor and outdoor) and To propose an instrumentation system consisting of wireless devices / As redes de sensores sem fio (RSSS) j? s?o uma realidade hoje em dia, pois a grande necessidade de conectividade entre os equipamentos existentes numa planta industrial impulsiona a pesquisa e o desenvolvimento de diversas tecnologias. O padr?o LR-WPAN IEE 802.15.4 apresenta-se como uma solu??o vi?vel, com baixo custo e baixo consumo de energia, requisitos importantes para a implanta??o de um sistema de sensoriamento remoto. A contribui??o deste trabalho consiste em propor um sistema de comunica??o sem fio, que possa monitorar vari?veis anal?gicas e/ou digitais (no caso do estudo em quest?o, a press?o) nos m?todos de eleva??o artificial de petr?leo e g?s natural. Os pontos principais deste estudo s?o: Desenvolver um software baseado no Padr?o SMAC com intuito de criar uma rede sem fio com fins de monitoramento de vari?veis anal?gicas e/ou digitais; Avaliar o enlace de comunica??o com rela??o a quantidade de pacotes perdidos em diferentes ambientes (ambientes internos (Indoor) e externos (Outdoor)) e, Propor um sistema de instrumenta??o utilizando tecnologia sem fio

Approved for public release, distribution is unlimited / The objective of this research is to analyze the network performance and sensor functionality, efficacy and usability of IEEE 802.x wireless MESH networks within a DoD Tactical network environment. Multiple sensor configurations operating with wireless MESH network technologies will be researched and analyzed for performance in expeditionary environment situations. Specifically, this thesis will attempt establish the foundation for the development of wireless MESH "network health" models by examining the performance of sensors operating within a MESH network and define which network performance metrics equate to good quality of service. This research will experiment with different application, sensor, and network configurations of currently available COTS components, such as, voice, video and data hardware. This thesis will lay the groundwork for wireless network MESH predictability, which will enable the optimal use of sensors within a tactical network environment. / Lieutenant Commander, United States Navy