The Internet of Things mission is to connect any objects to the Internet, in order to provide the ability to access everything, everywhere. It will enable people to control and monitor their environment in a very convenient way. In order to fulfill the Internet of Things mission, one idea is to wrap a non-IP based protocol stack in the objects equipped with sensors, actuators and computing resources to enable them to be connected to the Internet through a protocol translation gateway. An alternative and competing idea, is to embed the TCP/IP stack into such smart objects, enabling them to interact with the Internet seamlessly. However, in order to satisfy the Internet of Things needs such as scalability, interoperability and simplicity of configuration and management, the use of IP architecture for smart objects is of interest, since it has proven itself a highly scalable, interoperable and simple communication technology. In particular, the new optimized Internet Protocol, IPv6, which is capable of providing any single object with a unique address, accompanied by many other great features such as plug-and-play and a real end-to-end connectivity, can offer great benefits to the Internet of Things. Nevertheless, most of the smart objects specially deployed in Wireless Sensor Networks a subset of Internet of Things, are not able to adapt the large IPv6 packet because of their Link- Layer limitations. Hence, it is a quite challenging task for these devices to transmit an IPv6 packet. For this reason, the Internet Engineering Task Force organization has offered an IPv6 over Low-Power Wireless Personal Area Networks (6LoWPAN) solution in order to solve the IPv6 adaptability problem. This thesis presents the design and deployment of an IPv6-based WSN using this solution. The result of this work is building a 6LoWPAN based on the Contiki OS. This WSN is able to send the measured environment temperature to a web server and control the status of a light through the Internet in a standard, scalable, and seamless way.

Sensors are used to convert physical quantity into numerical data. Various types of sensors can be coupled together to make a single node. A distributed array of these nodes can be deployed to collect environmental data by using appropriate sensors. Application of low powered short range radio transceivers as a communication medium between spatially distributed sensor nodes is known as wireless sensor network. In this thesis I build such a network by using Arduino, Raspberry Pi and XBee. My goal was to accomplish a prototype system so that the collected data can be stored and managed both from local and remote locations. The system was targeted for both indoor and outdoor environment. As a part of the development a controlling application was developed to manage the sensor nodes, wireless transmission, to collect and store data using a database management service. Raspberry Pi was used as base station and webserver. Few web based application was developed for configuring the network, real time monitoring, and database management. Whole system functions as a single entity. The use of open source hardware and software made it possible to keep the cost of the system low. The successful development of the system can be considered as a prototype which needs to be expanded for large scale environmental monitoring applications.

Wireless Sensor Networks (WSNs) are networks of small devices, called motes, designed to monitor resources and report to a server. Motes are battery-powered and have very little memory to store data. To conserve power, the motes usually form clusters to coordinate their activities. In heterogeneous WSNs, the motes have different resources available to them. For example, some motes might have more powerful radios, or larger power supplies. By exploiting heterogeneity within a WSN can allow the network to stay active for longer periods of time. In WSNs, the communications between motes draw the most power. By choosing better clusterheads in the clusters to control and route messages, all motes in the network will have longer lifespans. By leveraging heterogeneity to select better clusterheads, I have developed Heterogeneous Clustering Control Protocol (HCCP). HCCP is designed to be highly robust to change and to fully utilize the resources that are currently available.

Wireless Sensor Networks (WSNs) are networks of small devices, called motes, designed to monitor resources and report to a server. Motes are battery-powered and have very little memory to store data. To conserve power, the motes usually form clusters to coordinate their activities. In heterogeneous WSNs, the motes have different resources available to them. For example, some motes might have more powerful radios, or larger power supplies. By exploiting heterogeneity within a WSN can allow the network to stay active for longer periods of time. In WSNs, the communications between motes draw the most power. By choosing better clusterheads in the clusters to control and route messages, all motes in the network will have longer lifespans. By leveraging heterogeneity to select better clusterheads, I have developed Heterogeneous Clustering Control Protocol (HCCP). HCCP is designed to be highly robust to change and to fully utilize the resources that are currently available.

ZigBee based Wireless Sensor Networks (WSN) and Wireless Local Area Networks (WLAN) utilize the same un-licensed 2.4GHz frequency band. In our research, it is noticed that ZigBee could suffer serious performance degradation due to the collocated WLAN interference. After going through the available literature and combining with a thorough statistical analysis of our experimental results, several important factors that severely impact the ZigBee packet transmission performance have been identified. Motivated by these findings, novel techniques are designed to improve the performance of ZigBee packet transmission under WLAN interference. ACK with Interference Detection (ACK-ID) technique is developed to improve the delivery rate of ACK packets, and consequently reduce the number of redundant retransmissions. In order to improve the energy efficiency, Adaptive Transmit Power Adjustment (ATPA) is proposed to adaptively adjust the optimal transmit power while maintaining the predefined Packet Loss Rate (PLR) requirement. Time Aware Backoff and Transmission (TABTx) technique controls the time spent on each packet transmission attempt so as to avoid the Transmit First In First Out Byte Register (TXFIFO) overflow. Adaptive Preamble Padding with Retransmission Control (APPRC) is proposed to improve the transmission efficiency while satisfying the PLR requirement by determining the appropriate number of protective preamble padding bytes and whether or not to adopt packet retransmission. All these novel techniques have been implemented in the Crossbow MICAz motes and evaluated through extensive experimental measurements in the testbed.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / The use of wireless data networks is ubiquitous in the consumer world. They have gained significant traction due to advantages afforded by the lack of wires. These same advantages can prove valuable in Flight Test for data acquisition. Sensor nodes are ideal candidates for low bandwidth wireless networks. Located in remote, hard to reach and hostile environments, wirelessly acquiring data from such sensor can solve a number of existing issues for FTI engineers. Implementing such wireless communication introduces a number of challenges such as guaranteeing reliable transfer of the sensor data and time synchronization of the remote nodes. This paper addresses wireless sensor acquisition, the associated challenges and discusses approaches and solutions to these problems.

An information technology that can combine the physical world and virtual world is desired. The Internet of Things (IoT) is a concept system that uses Radio Frequency Identification (RFID), WSN and barcode scanners to sense and to detect physical objects and events. This information is shared with people on the Internet. With the announcement of the Smarter Planet concept by IBM, the problem of how to share this data was raised. However, the original design of WSN aims to provide environment monitoring and control within a small scale local network. It cannot meet the demands of the IoT because there is a lack of multi-connection functionality with other WSNs and upper level applications. As various standards of WSNs provide information for different purposes, a hybrid system that gives a complete answer by combining all of them could be promising for future IoT applications. This thesis is on the subject of `Federated Sensor Network' design and architectural development for the Internet of Things. A Federated Sensor Network (FSN) is a system that integrates WSNs and the Internet. Currently, methods of integrating WSNs and the Internet can follow one of three main directions: a Front-End Proxy solution, a Gateway solution or a TCP/IP Overlay solution. Architectures based on the ideas from all three directions are presented in this thesis; this forms a comprehensive body of research on possible Federated Sensor Network architecture designs. In addition, a fully compatible technology for the sensor network application, namely the Sensor Model Language (SensorML), has been reviewed and embedded into our FSN systems. The IoT as a new concept is also comprehensively described and the major technical issues discussed. Finally, a case study of the IoT in logistic management for emergency response is given. Proposed FSN architectures based on the Gateway solution are demonstrated through hardware implementation and lab tests. A demonstration of the 6LoWPAN enabled federated sensor network based on the TCP/IP Overlay solution presents a good result for the iNET localization and tracking project. All the tests of the designs have verified feasibility and achieve the target of the IoT concept.

In a wireless network, the medium is a shared resource. The nodes in the network negotiate access of the shared resource using the Medium Access Control (MAC) protocol. The design of a MAC protocol for a sensor node is not the same as that for a wireless transceiver. Due to the transceiver characteristics, the MAC protocol design is limited in terms of medium access methods. However, in most cases, the protocols rely on simple access methods i.e. Time Division Multiple Access (TDMA) or Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA). Control and monitoring applications, running over a wireless network, are typical examples of Wireless Sensor Actuator Network (WSAN) application in industries. In an industrial network, the message deliveries must be time-bounded otherwise, they are of no use. This report aims to present the thesis work carried out at ABB AB, Västerås. The purpose of this thesis was to compare the performance of WLAN and WirelessHART when it comes to control applications. For the purpose of WLAN, the media access schemes are analyzed in terms of deadline misses. There are other metrices for the performance evaluation but our focus was on the latency, since it is very important in the field of industrial automation. NS-2 was used for the purpose of MAC layer analysis and it is also shown that PCF gives better performance as compared to DCF, in terms of deadline misses. Finally, WLAN is proven to accommodate more control loops as compared to WirelessHART for a given scenario.

Wireless sensor network technology has now been widely adopted. In many applications, distributed sensor nodes collect data at different locations and the location information of each node is required. The Global Positioning System is commonly used to identify the location of the nodes in such networks. Although GPS localization has consistent long-term accuracy, it is limited by the inherent dependency on a direct line of sight to 4 or more external satellites. The increasing demand for an embedded system providing reliable navigation solutions regardless of its operational environment has motivated investigations into the use of integrated systems that combine inertial sensors with GPS receivers. This research proposes a hardware architecture for location-based wireless sensor networks. In this architecture, each sensor node consists of a GPS receiver, a reduced set of low cost micro-electro-mechanical-system-based INS and a wireless transceiver. Sensor nodes in WSN are often equipped with irreplaceable batteries, which makes the power consumption crucial. To reduce the energy consumption, a microcontroller is used to control the power supply. Besides, a motion detection scheme is proposed by taking advantage of the ultra low-power wake-up function of the microcontroller. A low-power featured digital signal processor is used to accomplish the navigation computation using the Kalman filter for GPS/INS data fusion. Non-Holonomic Constraints derived velocity updates are applied to reduce the position errors. Field tests are conducted to verify the real-time performance of the proposed system with a positioning update rate of 20 Hz. The first test shows that the 2D INS/GPS integration can maintain the average system position error within 5 meters during a 60-second GPS outage. The second test used low cost inertial sensors. The average position error was 10.17 meters during a 20-second outage. The largest RMS value of position errors among these outages was within 14.5 meters. Furthermore, additional accuracy improvements of approximately 1.4 meters were achieved by utilizing NHC during GPS outages. The third test shows that the average error during a 30-second outage is approximately 20.6 meters for the on-foot scenario and 26.7 meters for the in-vehicle scenario. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2012-01-13 14:46:45.44

Els últims avenços en comunicacions sense fils i electrònica ha motivat l'aparició de les xarxes de sensors sense fils. Aquestes xarxes estan formades per un nou tipus de sensors de baixa potència i de baix cost que s\'on capa\c cos d'operar en rangs propers. La seva senzillesa i autonomia ha motivat el desenvolupament de moltes aplicacions en una gran varietat de camps. No obstant això, els nodes estan equipats amb uns recursos de processament de dades i capacitats de comunicació\'o limitats. Per tant, el desenvolupament de qualsevol aplicació planteja diversos problemes de disseny. Aquestes restriccions imposen un disseny d'aplicacions amb un caràcter distribuït i energèticament eficients. Els algoritmes de localització i seguiment són una d'aquestes aplicacions emergents que s'ha convertit en un camp d'interès per als investigadors. La informació d'enrutament de les xarxes de sensors est\`a sovint suportada en la localització dels nodes. A més, el coneixement de la posició permet donar, a les dades detectades, un sentit geogràfic. En lloc d'utilitzar els mètodes existents de localització globals, com el GPS, que són més complexos i costosos, els recents avenços demostren la viabilitat de mètodes locals. En aquesta tesi, hem centrat el nostre estudi dels algoritmes de localització i seguiment, en xarxes de sensors sense fils, en solucions distribuïdes basades en mesures de potència. Una de la qüestions més importants és l'obtenció d'un mètode el més senzill possible, i les mesures de potència s'han convertit en les més simples. A més, també volem obtenir el millor compromís entre obtenir la major fiabilitat de l'algorisme i maximitzar l'eficiència energètica. En primer lloc, hem considerat el desenvolupament d'algoritmes de localització cooperatius basats en mesures de potència rebuda en xarxes interiors estàtiques. Les mesures de potencia imposen el coneixement d'un model de propagació per tal d'obtenir una estimació de la distància entre nodes. Nosaltres proposem la introducció d'un mètode que estima l'exponent de pèrdua de potència per propagació mitjançant les mesures de potència fetes, en comparació a les normalment utilitzades campanyes de mesures fetes a priori. A més a més, els mètodes cooperatius en els quals basem la nostra proposta augmenten el nombre de nodes que cooperen durant el procediment d’estimació de la posició d'un node no localitzat . Dos s\'on els problemes principals que no s'han de menystenir quan s'utilitza un major nombre de nodes. D'una banda, a major nombre de nodes cooperants, major intercanvi de missatges, i, per tant, major consum d'energia. D'altra banda, la probabilitat d'utilitzar nodes llunyans s'incrementa, i, com m\'es gran sigui la distància entre nodes, l'error de la distància estimada ser\`a major, puix que utilitzem mesures de potència. Aquesta característica ens ha motivat a proposar tres criteris de selecció de nodes diferents per tal de reduir el nombre de nodes cooperants i així reduir el consum d'energia sempre intentant mantenir l'exactitud. Finalment, hem considerat la mobilitat dels nodes dins d'una xarxa fixa. L'interès és localitzar i seguir un node mòbil en una xarxa de sensor sense fils. En aquesta ocasió hem considerat dos escenaris diferents: una a l'aire lliure, on la velocitat és mitjana-alta, i un interior, on la velocitat és menor. En ambdós casos, també utilitzem un algorisme cooperatiu basat en mesures de potència. A més, el filtre de Kalman i els seus derivats s'introdueixen a la solució proposada, ja que s'han convertit en un solució d'ús comú als algoritmes de seguiment. En ambdós casos, la mobilitat del node produeix una alta variabilitat de les mesures de potència. Aquests errors poden causar una precisi\'o inferior. En aquest sentit, es proposa un mètode de correcció de les potències rebudes basat en un enfinestrat, per tal de disminuir aquests efectes negatius. / The last advances in wireless communications and electronics have motivated the appearance of Wireless Sensor Networks. These networks are formed by a new kind of low-power and low-cost sensors able to operate across short ranges. Their simplicity and autonomy have motivated the development of many final applications in a large variety of fields. Nevertheless, sensor nodes are equipped with limited data processing and communication capabilities. Hence, several design challenges appear when an application has to be developed. These restrictions justify the design of highly distributed and energy-efficient applications. Localization and tracking algorithms are one of those emerging applications that have become an interesting field to the researchers. The information routing is often supported by their localization. Besides, the location knowledge gives to the data sensed a geographic sense. Instead of using the existing global localization methods, such as GPS, that are more complex and costly, recent advances have demonstrated the viability of local methods. In this PhD dissertation, we have focused our study of the localization and tracking algorithms for WSN on the RSS-based distributed approaches. One of the major issues is to obtain the simplest possible method, and RSS range measurements have become the simplest existing measurements. Besides, we have also presented methods that are able to optimize the trade-of between accuracy versus energy-efficiency. First, RSS-based cooperative localization algorithms in static indoor networks are considered. The use of RSS measurements requires the knowledge of a propagation model in order to obtain inter-node distance estimates. We introduce an on-line path loss estimation method that obtains the model by means of RSS measurements. Hence, we avoid the need of an a priori estimation of the propagation model. Moreover, the cooperative approaches used increase the number of nodes that cooperate with a non-located node in the location estimation procedure. Two major issues have to be taken into account when a large number of nodes are used. On the one hand, the larger the number of cooperating nodes, the larger the number of messages exchanged, and, hence, the higher the energy consumption. On the other hand, the probability of using further nodes is increased, hence, the higher the distance, the higher the error distance estimates, when RSS measurements are used. These features have motivated us to propose three different node selection criteria in order to reduce the energy consumption maintaining the accuracy. Finally, we have considered the mobility of the non-located nodes inside a fixed network. The interest is to locate and track a node moving across a WSN. We have considered two different scenarios: an outdoor one, in which the velocity is medium-high, and, an indoor one, where the velocity is lower. In both cases, we have still used an RSS-based cooperative algorithm. Besides, we introduce the Kalman Filter and its derivatives, because, they have become a common approach used for tracking purposes. In both scenarios, the mobility of the node causes a high variability of the RSS measurements. These errors reduce the accuracy. In that sense, we propose a window-based RSS correction method in order to counteract these negative effects.