Examensarbetet genomfördes tillsammans med företaget Rol Ergo. Syftet med studien var att analysera Zigbee 3.0 och Bluetooth Low Energy 5.2 och deras lämplighet i tidskritiska system genom att studera latensen och förhållandet mellan signalstyrkan och avståndet mellan de två kommunikationsprodukter. Datainsamlingen genomfördes med en experimentell studie och utifrån kunskap som framskaffats har ett visst antal bestämda experiment utförts för att svara på frågeställningarna som ställs.  Datainsamlingen visar att både maxlatensen och typiska latensen hos Zigbee är lägre än maxlatens och typiska latens för Bluetooth Low Energy. Datainsamlingen för signalstyrkan visar att Bluetooth Low Energys signalstyrka blir mer påverkad av avståndet mellan kommunikationsprodukterna än vad Zigbees blir. Det visar även att den optimala förhållande mellan signalstyrkan och avståndet hos Zigbee är bättre än hos Bluetooth Low Energy.  Slutsatsen av arbetet är att Zigbee är mer lämpad för tidkritiska system än Bluetooth Low Energy då låg latensen prioriteras. Zigbee är även mer lämpad då lång distansen prioriteras men då bör signalstyrkan ligga runt -50dBm. Bluetooth Low Energy är dock mer lämpad då lång distans inte prioriteras och signalstyrkan inte behöver vara utmärkt för att kunna kommunicera.  Begränsningarna för arbetet är att Bluetooth Low Energy och Zigbee endast har prövats på utvecklingskortet nRF5340 DK.  På grund av den begränsade tiden så har endast ett antal bestämda experiment som har föreslagits av rådgivare på Rol Ergo utförts. / The thesis has been conducted together with  Rol Ergo company. The purpose of this study is to analyse Zigbee 3.0 and Bluetooth Low Energy 5.2 and their suitability for time-critical systems, by studying latency and the relations between signal strength and distance between two communication products. The data collection was completed by an experimental study. By using knowledge that has been collected for the study, sets of experiments will be performed to answer the research questions.  Results of the collected data indicate that both the maximum latency and the typical latency for Zigbee is significantly lower than for Bluetooth Low Energy. The collected data for signal strength shows that the signal strength for Bluetooth Low Energy is more affected by distance between the communication product, than Zigbee’s is. It also shows that the optimal ratio between signal strength and distance for Zigbee is better than for Bluetooth Low Energy. The conclusion of the study shows Zigbee to be a more suitable for time-critical systems compared to Bluetooth Low Energy when low latency is being prioritized. Zigbee is also more suitable for time-critical systems when long distance is being prioritized, however the signal strength must then be around -50 dBm. Bluetooth Low Energy is more suitable when long distance is not the priority, and the signal strength does not have to be excellent to be able to communicate.  The limitations for this thesis are that Bluetooth Low Energy and Zigbee will only be tested on the nRF5349 Development Kit. given limited time, only a certain of experiments, whereas some have been suggested by advisors from Rol Ergo, has been carried out.

With the increasing popularity of Internet of Things (IoT), network connected devices and sensors, to easier collect data is security an aspect that must not be forgotten. When sensitive data, such as personal or private data, is sent over the network without protection can it easier be obtained by anyone who want to get their hands on it. This risk increases with the value of the data sent and an increase in security should therefore follow this value. Based on this is it therefore important to look at the security aspects of a sensor network to find ways to easy integrate security such as authentication. This to make sure that the only devices and users accessing or sending data on the network is authorized and not malicious devices. This thesis focuses on the authentication and identification of the devices joining the network to make sure that only trusted devices would be able to join. The protocol in focus is ZigBee but the proposed solution can be integrated with any protocol and utilizes a Key Distribution Center (KDC) together with an authentication method based on the Challenge Handshake Authentication Protocol (CHAP) to authenticate new devices before they are allowed into the network. This solution is secure and relatively simple which makes it easy to integrate with any sensor network. / Med en ökad popularitet av att koppla upp sensorer och apparater mot ett nät- verk för att enklare kunna samla in data är säkerhet en aspekt som inte får glömmas bort. När känslig data, så som personlig eller privat data, skickas över nätverket oskyddat kan någon som vill komma åt datan lättare få tag på den. Denna risk ökar med värdet av datan som skickas och en ökningen av säkerhet bör darav följa ökning av värdet på datan. Utav denna anledning är det viktigt att se över säkerheten i sensornätverk och finna lösningar som lätt kan integreras med ett sensornätverk. Detta för att säkerhetsställa att endast de snesornoder som har auktoritet kan gå med i, samt skicka data på nätverket och därmed undvika oönskad åtkomst. Denna avhandling fukuserar på autentisering och identifiering av de noder som ska anslutas till nätverket för att säkerhetsställa att endast pålitliga och auktoriserade noder blir insläppta. Det protokoll som är i fokus i denna avhandling är ZigBee men den föreslagna lösningen kan även integreras med andra protokoll. Den föreslagna lösning- en använder sig även av ett Key Distribution Center (KDC) samt en autentiseringsmetod som baseras på Challenge Handshake Authentication Protocol (CHAP) för att authentisera nya noder innan de blir insläppta i nätverket. Denna lösning är säker och relativt enkel vilket gör det enkelt att integrera med all typer av sensornätverk.

Master of Science / Department of Electrical and Computer Engineering / Steven Warren / Networks of low-power, in-suit, wired and wireless health sensors offer the potential to track and predict the health of astronauts engaged in extra-vehicular and in-station activities in zero- or reduced- gravity environments. Fundamental research questions exist regarding (a) types and form factors of biomedical sensors best suited for these applications, (b) optimal ways to render wired/wireless on-body networks with the objective to draw little-to-no power, and (c) means to address the wireless transmission challenges offered by a spacesuit constructed from layers of aluminized mylar. This thesis addresses elements of these research questions through the implementation of a collection of ZigBee-based wireless health monitoring devices that can potentially be integrated into a spacesuit, thereby providing continuous information regarding astronaut fatigue and state of health. Wearable biomedical devices investigated for this effort include electrocardiographs, electromyographs, pulse oximeters, inductive plethysmographs, and accelerometers/gyrometers. These ZigBee-enabled sensors will form the nodes of an in-suit ZigBee Pro network that will be used to (1) establish throughput requirements for a functional in-suit network and (2) serve as a performance baseline for future devices that employ ultra-low-power field-programmable gate arrays and micro-transceivers. Sensor devices will upload data to a ZigBee network coordinator that has the form of a pluggable USB connector. Data are currently visualized using MATLAB and LabVIEW.

ITC/USA 2008 Conference Proceedings / The Forty-Fourth Annual International Telemetering Conference and Technical Exhibition / October 27-30, 2008 / Town and Country Resort & Convention Center, San Diego, California / Adding an instrumentation / telemetry system to a test article has historically required an intrusive installation. Power, wiring, and available space typically present significant challenges. There has been a long-standing need in the test and training community for a non-intrusive, flexible and modular instrumentation and telemetry system that can be installed on an aircraft or other test article without the need for permanent modifications. In addition, as available space in aircraft weapon bays, small weapons, and unmanned vehicles becomes a premium, the miniaturization of remote sensors and telemetry units becomes critical. This paper describes the current status of the Advanced Subminiature Telemetry System (ASMT) Initial Test Capability Project. It discusses the progress to date in fielding an operational, wireless sensor system that may be installed on the aircraft skin using an Electro-Cleavable adhesive as an alternative to conventional mounting methods. The wireless sensor utilizes the Wireless Communications Standard for Wireless Personal Area Network™ (WPAN™) IEEE 802.15 Working Group standard (commonly referred to as Bluetooth) to establish communication between the sensor and controller modules. Results of aircraft ground testing for EMI compatibility with aircraft systems will be presented. It is also expected that actual flight test results will be available by the time the paper goes to publication.

ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Adding an instrumentation / telemetry system to a test article has historically required an intrusive installation. Power, wiring, and available space typically present significant challenges. There has been a long-standing need in the test and training community for a non-intrusive, flexible and modular instrumentation and telemetry system that can be installed on an aircraft or other test article without the need for permanent modifications. In addition, as available space in aircraft weapon bays, small weapons, and unmanned vehicles becomes a premium, the miniaturization of remote sensors and telemetry units becomes critical. This paper describes the current status of the Advanced Subminiature Telemetry System (ASMT) Initial Test Capability Project. It discusses the challenges that have been overcome in developing a wireless sensor network system for use in an airborne test environment. These include wireless sensor packaging design, selection of operating frequencies, COTS wireless devices, batteries, system synchronization and data bandwidth calculations. The paper will also document the progress to date including preliminary test results.

This work is concerned with the design design full functional nodes and to evaluate an application in wireless sensor network. The resulting designed product could form a reliable support for transferring data between nodes and a computer. MaxStream XBee ZNet 2.5 modules are chosen as the radio platform and LabVIEW as the virtual instrument for user interface.

Un réseau de capteur sans fil est un ensemble de noeuds communicants, généralement miniatures et capables de fonctionner avec peu d'énergie. Certaines applications imposent à ces réseaux de capteurs sans fil d'être économes en énergie pour prolonger la durée de vie du réseau, d'autres nécessitent un comportement déterministe qui se traduit généralement par des délais de traversée du réseau bornés et/ou un taux de trames perdues inférieur à un seuil critique. Pour économiser significativement de l'énergie, une entité doit se mettre en mode sommeil. Durant cette période, elle sera inactive donc incapable de participer à l'ativité du réseau. L'usage de périodes de sommeil est un handicap pour l'aspect déterministe et pour le respect de contraintes temporelles. Le travail de cette thèse est centré sur les spécifications, le dévelopement et l'évaluation sous différentes formes d'une méthode d'accès au medium adaptée au déterminisme et aux exigences de qualité de service telles que l'absence de collisions et la garantie d'un délai borné de bout-en-bout, tout en conservant une faible consommation énergétique. La solution proposée repose sur la segmentation temporelle des activités, une synchronisation multi-sauts et une différentiation de services basée sur des stratégies de routage adaptées.

In recent years, advances in signal processing have led to small, low power, inexpensive Wireless Sensor Network (WSN). The signal processing in WSN is different from the traditional wireless networks in two critical aspects: firstly, the signal processing in WSN is performed in a fully distributed manner, unlike in traditional wireless networks; secondly, due to the limited computation capabilities of sensor networks, it is essential to develop an energy and bandwidth efficient signal processing algorithms. Target localisation and tracking problems in WSNs have received considerable attention recently, driven by the necessity to achieve higher localisation accuracy, lower cost, and the smallest form factor. Received Signal Strength (RSS) based localisation techniques are at the forefront of tracking research applications. Since tracking algorithms have been attracting research and development attention recently, prolific literature and a wide range of proposed approaches regarding the topic have emerged. This thesis is devoted to discussing the existing WSN-based localisation and tracking approaches. This thesis includes five studies. The first study leads to the design and implementation of a triangulation-based localisation approach using RSS technique for indoor tracking applications. The presented work achieves low localisation error in complex environments by predicting the environmental characteristics among beacon nodes. The second study concentrates on investigating a fingerprinting localisation method for indoor tracking applications. The proposed approach offers reasonable localisation accuracy while requiring a short period of offline computation time. The third study focuses on designing and implementing a decentralised tracking approach for tracking multiple mobile targets with low resource requirements. Despite the interest in target tracking and localisation issues, there are few systems deployed using ZigBee network standard, and no tracking system has used the full features of the ZigBee network standard. Tracking through the ZigBee is a challenging task when the density of router and end-device nodes is low, due to the limited communication capabilities of end-device nodes. The fourth study focuses on developing and designing a practical ZigBee-based tracking approach. To save energy, different strategies were adopted. The fifth study outlines designing and implementing an energy-efficient approach for tracking applications. This study consists of two main approaches: a data aggregation approach, proposed and implemented in order to reduce the total number of messages transmitted over the network; and a prediction approach, deployed to increase the lifetime of the WSN. For evaluation purposes, two environmental models were used in this thesis: firstly, real experiments, in which the proposed approaches were implemented on real sensor nodes, to test the validity for the proposed approaches; secondly, simulation experiments, in which NS-2 was used to evaluate the power-consumption issues of the two approaches proposed in this thesis.

With the ever increasing number of Internet of Things devices going out on the market for consumers that are Zigbee certified there is a need for security testing. This is to make sure that security standards are upheld and improved upon in order to make sure networks are protected from unauthorized users. Even though a lot of research and testing has been done on the Zigbee key exchange mechanism, called Zigbee commissioning, improvements have still not been enough with severe vulnerabilities in consumer grade devices still existing today. The devices tested in this study use EZ-mode commissioning in order to exchange the network key between a Zigbee coordinator and a Zigbee end device in order to encrypt later communication after being paired.  By using a simple radio receiver and a packet capturing program such as Wireshark an eavesdropping attack was conducted in order to capture the network key. The experiment demonstrates that this is still a weak point as the network key was successfully captured using eavesdropping. The analysis of the results show that previous criticisms of Zigbee commissioning have still not fully been addressed and can be a potential weak point in networks that use Zigbee certified IoT products.

This research studies the security challenges in IoT devices. At first, security challenges have been described and then specifically the security of communication protocols in the IoT has been addressed. Finally, among different communication protocols, ZigBee and Z-Wave protocols have been chosen for this study. The criterion for choosing these two protocols is the level of security they provide for IoT devices to protect them against unauthorized access and hacking. Security, frequency, power consumption and data rate are the characteristics that have been discussed in the review of these two protocols. In the end, a comparison of the various features of these two protocols clarified that the security of IoT devices in each of these protocols depends on the type of the IoT device, the required range and other requirements, however, in most cases the ZigBee protocol showed more security than Z-Wave.