Development of technical and methodological support has been identified as a key area for future research and development within the search and rescue (SAR) of missing persons in Sweden. Previous studies have demonstrated the feasibility of using Wi-Fi signals to locate a missing person, and also developed hardware and software for SAR systems based around Unmanned Aerial Vehicles (UAV). This thesis empirically studies the actual transmission behaviour of three non-connected smartphones over Wi-Fi and Bluetooth Low Energy (BLE), under the assumption that a missing person could be carrying a smartphone with them. Furthermore, the thesis studies the range of relatively low-cost off-the-shelf Wi-Fi and BLE devices in a “best-case” scenario with free line-of-sight and a slightly elevated transmitter. Finally, the thesis studies how antennas and other factors impact range. The results show that all of the tested smartphones transmit so called Wi-Fi probe packets when Wi-Fi is enabled. Though, these probes are, in most cases, transmitted during short events separated by intervals of 5 to 9 minutes, depending on the smartphone. Furthermore, in most cases only a few packets are transmitted in each event. The interval lengths and scarce packets imply significant limitations to the usability of Wi-Fi in SAR. BLE broadcast transmissions, on the other hand, require that some kind of advertising service is enabled, but are transmitted at least every 10.5 seconds, due to the strict regulation in the Bluetooth standard. This was also demonstrated with the studied iPhone that continuously transmitted BLE packets every two seconds. Roughly 60 % of the smartphones in use in Sweden today are Apple devices, thus a significant portion of all the smartphones in use are likely to be detectable via BLE within brief time intervals. In the tested “best-case” scenario with free line-of-sight and a slightly elevated transmitter, at least 80 % of the transmitted Wi-Fi probes are detected up to 500-600 meters with a maximum range, with sparsely detected packets, of up to about 700 meters. Correspondingly, at least 80 % of the BLE advertisements are detected up to 60-110 meters with occasional packets detected up to a maximum range of approximately 210 meters. However, the ranges for both Wi-Fi and BLE are highly dependent on the receiving device. In addition to the receiver device and standard, it is found that the transmission power and antenna directivity of the transmitter have a potentially substantial impact on the range with a possible combined difference in directed transmitted power of up to 49 dB. This corresponds to the difference between a strong signal and no detected signal at all. In summary, there are clear differences between the properties of BLE and Wi-Fi, both in terms of range and how different devices transmit broadcast packets (transmission behaviour), resulting in both having advantages and disadvantages in SAR applications. There are also a number of factors on the transmitter and receiver devices that could have considerable impact on the possibility of detecting a device. Concludingly, both BLE and Wi-Fi could fill a role in SAR of missing persons, but both also have major drawbacks that are severely limiting their possible use. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

Antenna is a key component in wireless devices such as cell phones, laptops and smartwatches. With the new generation of Wi-Fi technology: Wi-Fi 6E coming out, 1200MHz bandwidth from 5.925GHz to 7.125GHz is freed for use. Mobile devices are expected to meet the required bandwidth allocated for Wi-Fi 6E. However, electrically small antenna design for Wi-Fi 6 and 6E applications has been a challenge. Reducing the size of antennas while maintaining the performance is one major issue. The goal of this project is to evaluate different antennas and try to find the potential compact antenna that could cover Wi-Fi 6 and Wi-Fi 6E bands. In this project, we evaluated different types of electrically small antennas, explored parameters that affect antenna performance, characterized one nominated antenna in High Frequency Simulation Software(HFSS), prototyped the antenna in Altium Designer and measured the antenna performance using Network Analyzer. The measurement result shows that the proposed antenna is omni-directional, partially meet the fixed frequency requirement and has low efficiency at 2.4GHz but good efficiency at 6GHz bands. The conclusion is that the proposed antenna is good for the extended bandwidth of Wi-Fi 6 but for the whole Wi-Fi 6E the performance still needs to be improved in future work. / Antenn är en nyckelkomponent i trådlösa enheter som mobiltelefoner, bärbara datorer och smartklockor. Med den nya generationens Wi-Fi-teknik: Wi-Fi 6E kommer ut, 1200MHz bandbredd från 5,925GHz till 7,125GHz frigörs för användning. Mobila enheter förväntas uppfylla den erforderliga bandbredden som tilldelats för Wi-Fi 6E. Däremot har en elektrisk liten antenndesign för Wi-Fi 6 och 6E-applikationer varit en utmaning. Att minska storleken på antennerna samtidigt som prestandan bibehålls är en stor fråga. Målet med detta projekt är att utvärdera olika antenner och försöka hitta den potentiella kompakta antennen som kan täcka Wi-Fi 6- och Wi-Fi 6E-banden. I det här projektet utvärderade vi olika typer av elektriskt små antenner, utforskade parametrar som påverkar antennprestanda, karakteriserade en nominerad antenn i High Frequency Simulation Software (HFSS), prototypade antennen i Altium Designer och mätte antennens prestanda med hjälp av Network Analyzer. Mätresultatet visar att den föreslagna antennen är rundstrålande, delvis uppfyller kravet på fast frekvens och har låg verkningsgrad vid 2,4GHz men bra effektivitet vid 6GHz-band. Slutsatsen är att den föreslagna antennen är bra för den utökade bandbredden för Wi-Fi 6 men för hela Wi-Fi 6E behöver prestandan fortfarande förbättras i framtida arbete.

Då data som transporteras över trådlösa nätverk sänds genom luften i form av radiovågor är det viktigt att säkra upp nätverkskommunikationen med nya, erkändasäkerhetsstandarder. Däremot är användningsgraden av nyare säkerhetsstandarder inom Wi-Fi, specifikt WPA3 och PMF, låg. Samtidigt finns ett behov att öka förståelsen för relevanta metoder för kunskapsinhämtning. Syftet med studien är att ge rekommendationer för hur små och medelstora företag kan öka säkerheten i trådlösa nätverk. Studien identifierar orsaker till den låga användningsgraden av nyare säkerhetsstandarder i trådlösa nätverk och även hur nätverksadministratörer håller sig uppdaterade om standarderna. En kvalitativ ansats valdes för att besvara studiens syfte, vilket genomfördes med hjälp av 23 semi-strukturerade intervjuer med nätverksadministratörer i Sverige. Studiens resultat visar på ett tydligt tema där klientbasen i nätverken är huvudanledningen till avvaktandet med att implementera nyare säkerhetsstandarder, där kompabilitet upplevs som ett problem samtidigt som det råder okunskap om standarderna. Bland respondenterna anses metoden praktiskt laborerande vara mest effektiv för kunskapsinhämtning och fortbildning, ofta i samband med läsande av teori för att bilda en grundläggande förståelse. Studien landar i rekommendationer om de nyare säkerhetsstandarderna och kunskapsinhämtning riktade mot nätverksadministratörer, företag och även myndigheter och organisationer som bidrar med riktlinjer om trådlösa nätverk. / As data transmitted over wireless networks is sent through air, in the form of radio waves, it is important to secure network communication with new, recognized security standards. However, the adoption rate of newer security standards in Wi-Fi, specifically WPA3 and PMF, is low. At the same time, there is a need to increase understanding of relevant methods for knowledge acquisition. This study’s purpose is to provide recommendations on how small and medium-sized enterprises can increase the security of wireless networks. The study identifies reasons for the low adoption rate of newer security standards in wireless networks and how network administrators stay updated on the standards. A qualitative approach was chosen to address the study's purpose, which was conducted through 23 semi-structured interviews with network administrators in Sweden. The study's results reveal a clear theme where the client base in the networks is the main reason for reservations to implement newer security standards, with compatibility being perceived as a problem alongside a lack of knowledge about the standards. Among the respondents, practical experimentation is considered the most effective method for knowledge acquisition and continuous education, often combined with reading of theory to form a fundamental understanding. The study concludes with recommendations on the newer security standards and knowledge acquisition targeted towards network administrators, companies, as well as authorities and organizations that provide guidelines on wireless networks.

In diese Dissertation, Ich konzentriere mich insbesondere darauf, wie die Artbestimmung in der Gattung Eimeria mit der Wirtsspezifität bei Nagetierarten zusammenhängt. Zunächst bietet diese Arbeit eine Reihe von Methoden zur Beurteilung der Prävalenz auf der Ebene der Parasitenarten in Mus musculus. Als Ergebnis war es möglich, drei verschiedene Eimeria-Spezies zu identifizieren, Mäuse mit Doppelinfektionen zu erkennen und die artenspezifische Prävalenz in Abhängigkeit von der Wirtsdichte vorherzusagen. Zur Identifizierung von Eimeria spp. über verschiedene Wirtsarten hinweg wurde eine neuartige Hochdurchsatz-Multi-Locus-Genotypisierungsmethode etabliert und mit der auf zuvor etablierten Markern basierenden Einzelmarker-Genotypisierung verglichen. Dies bestätigte, dass die Art E. falciformis in einer einzigen Wirtsart, der Hausmaus, vorkommt. E. vermiformis und E. apionodes konnten jedoch nicht unterschieden werden, was auf eine einzige Art mit breitem Wirtsspektrum hindeutet. E. vermiformis und E. apionodes konnten jedoch nicht unterschieden werden, was auf eine einzige Art mit breiter Wirtsverwendung in einem phylogenetischen Artkonzept schließen lässt. Diese Ergebnisse zeigen, dass die hohe Wirtsspezifität, die traditionell für Eimeria-Parasiten angenommen wird, fragwürdig ist und dass die Identifizierung von Arten durch Wirtsassoziation vermieden werden sollte. Durch molekulare Amplifikation, Sequenzierung, Genotypisierung und phylogenetische Analyse war es möglich, Eimerien auf Artniveau zu identifizieren und die Wirtsspezifität in Isolaten aus natürlichen Systemen in Frage zu stellen. In einer breiteren Perspektive betonte diese Arbeit die Notwendigkeit, Strategien bei der Erkennung, Quantifizierung und Identifizierung von Parasiten zu standardisieren und zu kombinieren, um ein besseres Verständnis auf evolutionärer und ökologischer Ebene zu erlangen. / This PhD thesis combines different approaches for parasite identification to assess the diversity of parasites in natural systems. Particularly, I focus on how species identification in the genus Eimeria is linked to its host specificity in rodent species. First, this thesis provides a set of methods to assess prevalence at the species level in Mus musculus systems. The approach integrates morphological description with molecular methods for detection, niche approximation and phylogenetic reconstruction. As a result, three different Eimeria species were identified, mice with double infections were detected and species-specific prevalence were predicted to be host density-dependent. For identification of Eimeria spp. across different host species, a novel high-throughput multi-locus genotyping was established and compared with single-marker genotyping. The multi-locus genotyping approach provided a higher resolution to distinguish closely related Eimeria isolates. This confirmed the species E. falciformis to have a single host species, the house mice. However, E. vermiformis and E. apionodes could not be distinguished suggesting a single species with broader host usage in a phylogenetic species concept. These findings show that the high host specificity traditionally assumed for Eimeria parasites is questionable, and that identification of species by host association should be avoided. The approaches for identification of Eimeria spp. Developed here allowed differentiation of closely related isolates with indistinguishable morphology. Molecular amplification, sequencing, genotyping and phylogeny allowed the identification of Eimeria at species level and to question host specificity in isolates from natural systems. In a broader perspective, this work emphasised the necessity to standardise and combine strategies in parasite detection, quantification and identification to gain better understanding at an evolutionary and ecological level.

Künstliches Licht in der Nacht (ALAN) entsteht in Zentren menschlicher Aktivität und erhellt die Nacht, wodurch biologische Rhythmen von Menschen und Wildtieren gestört werden können. Skyglow ist eine diffuse Aufhellung des Nachthimmels aufgrund von Reflexion und Streuung von ALAN, welche indirekt große Bereiche (vor-)städtischer Ökosysteme beleuchtet. Da sich Zentren menschlicher Aktivität häufig in der Nähe von Flüssen und Seen befinden, kann sich Skyglow unverhältnismäßig stark auf wildlebende Tiere in Süßwassergebieten auswirken. In drei Experimenten wurden die Auswirkungen von ALAN auf die Physiologie des Europäischen Flussbarsches untersucht. Die Fische wurden verschiedenen Versuchsbedingungen ausgesetzt: 1) niedrige ALAN-Intensitäten von 0,01, 0,1 und 1 lx unter kontrollierten Bedingungen, 2) höhere ALAN-Intensitäten von 1, 10 und 100 lx unter kontrollierten Bedingungen und 3) eine niedrige ALAN-Intensität von 0,06 lx in einem Feldexperiment. In den vorgestellten Experimenten unterdrückten niedrige ALAN-Intensitäten den nächtlichen Melatoninspiegel sowie teilweise Reproduktionshormone bei Weibchen. Höhere ALAN-Intensitäten verringerten das aktivste Schilddrüsenhormon und das relative Lebergewicht der Fische. Diese Arbeit zeigt physiologische Veränderungen bereits bei schwachen ALAN-Intensitäten, wie sie in großen Bereichen (vor-)städtischer Ökosysteme in Form von Skyglow vorkommen. Die empfindlichste Reaktionsvariable auf die Belastung durch ALAN bei Fischen ist der nächtliche Melatoninspiegel. Mögliche Wirkungen von ALAN auf andere physiologische Parameter können durch direkten Lichteinfall oder indirekt über reduziertes Melatonin ausgelöst werden. Diese Arbeit trägt zum Verständnis der Schwellenwerte für verschiedene physiologische Effekte durch eine mehrwöchige ALAN-Exposition bei. Schwellenwerte für ALAN-Intensitäten könnten zukünftig notwendige Deskriptoren für die Ausarbeitung von regulierenden Maßnahmen zur Reduzierung von Lichtverschmutzung liefern. / Artificial light at night (ALAN) is emitted from centers of human activities and increasingly brightens up nights, which can disturb biological rhythms of humans and wildlife. Skyglow is a diffuse brightening of the night sky due to reflection and scattering of ALAN, which indirectly illuminates large areas of (sub-)urban ecosystems. As centers of human activities are usually located close to rivers and lakes, skyglow may disproportionally affect wildlife of freshwater. Three experiments tested for effects of ALAN on the physiology of Eurasian perch. Fish were exposed 1) to low nocturnal illuminances of 0.01, 0.1 and 1 lx under controlled conditions, 2) to higher nocturnal illuminances of 1, 10 and 100 lx under controlled conditions, and 3) to low nocturnal illuminance of 0.06 lx in a field experiment. In the presented experiments, low nocturnal illuminance suppressed nocturnal melatonin production and reduced reproductive hormones to some extent in females. Higher nocturnal illuminance reduced the most active thyroid hormone and reduced relative liver weight of the fish. This thesis shows physiological changes already at very weak intensities of ALAN, like they occur over large areas of (sub-)urban ecosystems in the form of skyglow. The most sensitive response variable to ALAN exposure is the nocturnal melatonin levels. Possible actions of ALAN on other physiological parameters can be either by direct perception of light or indirectly via reduced melatonin. This thesis contributes to an understanding of thresholds for several physiological effects caused by ALAN exposure of several weeks. Thresholds for ALAN intensities could provide the necessary descriptors for elaborating regulatory measures to reduce light pollution in the future.

IoT devices have historically lacked in the security standards but at the same time it is a continuously growing market it is important that the security analyzes continue in order to evaluate the development of the security in the IoT industry. This research is a security analysis of the Deltaco SH-IPC05 WIFI Camera, it is an inexpensive device that can be accessed through a mobile application from anywhere on the internet via the cloud. It follows the Practical and Agile Threat Research for IoT (PatrIoT) methodology and is delimited to network traffic and the software of the device. Due to legal limitations the cloud is not included in the analysis and the hardware security is not included due to time constraints. The device was found to use default credentials for its Open Network Video Interface Forum (ONVIF) service, but it is easy for a user to change the default password from the mobile application if the user can guess what the default password is, and the service is not enabled by default. Three DoS attacks were identified to be effective, two of which caused the device to crash and reboot and the third one prevented the camera from responding until the attack ended. One of the attacks that consistently crashed the camera, could keep crashing the camera repeatedly thus keeping it offline. When analyzing the network traffic, it was possible to consistently detect the packets that notified users of motion or sound detection by looking for specific TCP packet sizes and ports. Although some issues were found the device appeared to be generally secure with encrypted network traffic and minimally exposed services. / Bland IoT-enheter har säkerheten historiskt sett ofta varit eftersatt men det är samtidigt en ständigt växande marknad, därför är det viktigt att säkerhetsanalyserna fortsätter för att utvärdera utvecklingen av säkerheten inom IoT industrin. Denna rapport är resultatet av en säkerhetsanalys av Deltaco SH-IPC05 WIFI Camera, det är en billig enhet som kan nås genom en mobilapplikation via molnet. Den följer metodiken för Practical and Agile Threat Research for IoT (PatrIoT) och är avgränsad till nätverkstrafik och enhetens programvara. På grund av juridiska begränsningar ingår det inte att analysera molnet och hårdvara ingår inte på grund av tidsbrist. Enheten visade sig använda standardlösenord för sin ONVIF-tjänst men tjänsten måste aktiveras av användaren och det är möjligt att ändra lösenordet via mobilapplikationen om användaren kan gissa sig till standardlösenordet. Enheten var mottaglig för tre olika DoS-attacker. Två av dem fick kameran att krasha och starta om varav en av dem kunde återupprepas för att hålla enheten offline så länge som önskades. Det var möjligt att identifiera de paket som skickades från kameran när den skulle notifiera användare om upptäckta rörelser eller ljud. Även om vissa problem hittades verkade enheten vara säker i allmänhet med krypterad nätverkstrafik och minimalt exponerade tjänster.

Kriging is proposed as a tool for Wi-Fi signal strength estimation for complex indoor environments. This proposal is based on two studies suggesting that kriging might be suitable for this application. Both of these studies have shortcomings in supporting this proposal, but their results encourage a more in depth investigation into this. Even though kriging is a geostatistical method developed for geographical interpolation, it has been used successfully in a wide range of other applications as well. This further suggests that kriging might be a versatile method to overcome some of the difficul- ties of existing signal strength estimation methods. Two main types of signal strength estimation are deterministic methods and empirical methods. Deterministic methods are generally very complex and requires input parameters that are difficult to obtain. Empirical methods are known to have low accuracy which makes them unreliable for practical use. Three main investigations are presented in order to evaluate the use of kriging for this application. A sampling plan is proposed as part of a generic application protocol for the practical use of kriging for Wi-Fi signal strength. It is concluded that kriging can be conffidently used as an estimation technique for Wi-Fi signal strength in complex indoor environments. Kriging is recommended for practical applications, especially where in- sufficient information is available about a building or where time consuming site surveys are not feasible. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015

Kriging is proposed as a tool for Wi-Fi signal strength estimation for complex indoor environments. This proposal is based on two studies suggesting that kriging might be suitable for this application. Both of these studies have shortcomings in supporting this proposal, but their results encourage a more in depth investigation into this. Even though kriging is a geostatistical method developed for geographical interpolation, it has been used successfully in a wide range of other applications as well. This further suggests that kriging might be a versatile method to overcome some of the difficul- ties of existing signal strength estimation methods. Two main types of signal strength estimation are deterministic methods and empirical methods. Deterministic methods are generally very complex and requires input parameters that are difficult to obtain. Empirical methods are known to have low accuracy which makes them unreliable for practical use. Three main investigations are presented in order to evaluate the use of kriging for this application. A sampling plan is proposed as part of a generic application protocol for the practical use of kriging for Wi-Fi signal strength. It is concluded that kriging can be conffidently used as an estimation technique for Wi-Fi signal strength in complex indoor environments. Kriging is recommended for practical applications, especially where in- sufficient information is available about a building or where time consuming site surveys are not feasible. / MIng (Computer and Electronic Engineering), North-West University, Potchefstroom Campus, 2015

Wireless networks have become ubiquitous, where a wide range of mobile devices are connected to a larger network like the Internet via wireless communications. One widely used wireless communication standard is the IEEE 802.11 protocol, popularly called Wi-Fi. Over the years, the 802.11 has been upgraded to different versions. But most of these upgrades have been focused on the improvement of the throughput of the protocol and not enhancing the security of the protocol, thus leaving the protocol vulnerable to attacks. The goal of this research is to develop and implement an intrusion detection system based on anomaly behavior analysis that can detect accurately attacks on the Wi-Fi networks and track the location of the attacker. As a part of this thesis we present two architectures to develop an anomaly based intrusion detection system for single access point and distributed Wi-Fi networks. These architectures can detect attacks on Wi-Fi networks, classify the attacks and track the location of the attacker once the attack has been detected. The system uses statistical and probability techniques associated with temporal wireless protocol transitions, that we refer to as Wireless Flows (Wflows). The Wflows are modeled and stored as a sequence of n-grams within a given period of analysis. We studied two approaches to track the location of the attacker. In the first approach, we use a clustering approach to generate power maps that can be used to track the location of the user accessing the Wi-Fi network. In the second approach, we use classification algorithms to track the location of the user from a Central Controller Unit. Experimental results show that the attack detection and classification algorithms generate no false positives and no false negatives even when the Wi-Fi network has high frame drop rates. The Clustering approach for location tracking was found to perform highly accurate in static environments (81% accuracy) but the performance rapidly deteriorates with the changes in the environment. While the classification algorithm to track the location of the user at the Central Controller/RADIUS server was seen to perform with lesser accuracy then the clustering approach (76% accuracy) but the system's ability to track the location of the user deteriorated less rapidly with changes in the operating environment.

No description available.