A unified radio control architecture for prototyping adaptive wireless protocols

Experimental optimization of wireless protocols and validation of novel solutions is often problematic, due to limited configuration space present in commercial wireless interfaces as well as complexity of monolithic driver implementation on SDR-based experimentation platforms. To overcome these limitations a novel software architecture is proposed, called WiSHFUL, devised to allow: i) maximal exploitation of radio functionalities available in current radio chips, and ii) clean separation between the logic for optimizing the radio protocols (i.e. radio control) and the definition of these protocols

A survey of self organisation in future cellular networks

This article surveys the literature over the period of the last decade on the emerging field of self organisation as applied to wireless cellular communication networks. Self organisation has been extensively studied and applied in adhoc networks, wireless sensor networks and autonomic computer networks; however in the context of wireless cellular networks, this is the first attempt to put in perspective the various efforts in form of a tutorial/survey. We provide a comprehensive survey of the existing literature, projects and standards in self organising cellular networks. Additionally, we also aim to present a clear understanding of this active research area, identifying a clear taxonomy and guidelines for design of self organising mechanisms. We compare strength and weakness of existing solutions and highlight the key research areas for further development. This paper serves as a guide and a starting point for anyone willing to delve into research on self organisation in wireless cellular communication networks

Out-of-band transfer with Android to configure pre-shared secrets into sensor nodes

Applications based on Wireless Sensor Networks are making their way into all kinds of industries. Today, they can do anything from off-loading hospitals by monitoring patients in their homes to regulating production lines in factories. More often than not, they perform some kind of surveillance and tracking. Thus, in most cases the information they carry is sensitive, rendering good encryption schemes suited for performance-constrained sensor nodes a valuable commodity. As traditional encryption is not well suited for performance constrained environments, there are many new "lightweight" encryption schemes emerging. However, many of the popular up and coming schemes make the assumption of already having a pre-shared secret available in the sensor node beforehand which can act as the base for their encryption key. The procedure of configuring this pre-shared secret into the sensor node is crucial and has the potential of breaking any scheme based on that assumption. Therefore, we have looked at different procedures of configuring this pre-shared secret into a sensor node securely, using nothing more than a smartphone to configure the sensor node. This would eventually eliminate the assumption of how the pre-shared secret got into the sensor node in the first place. We used an Arduino Uno R3 running an Atmega328p MCU as a simulation of a potential sensor node. Moreover, using a smartphone as the configuration device, we chose to base the communication on two types of OOB based side-channels; Namely, a visual-based using the flashlight and screen as well as audio-based, using the loudspeaker. We concluded that using a smartphone as configuration device has its difficulties, although, in this specific environment it is still a viable choice. The solution can decrease the previous knowledge required by the user performing the configuration while simultaneously upholding a high security level. The findings of this thesis highlight the fact that: technology has evolved to a point where the smartphones of today can outperform the specialized devices of yesterday. In other words, solutions previously requiring specialized hardware can today be achieved with much less "specialized" equipment. This is desirable because with less specialized equipment, it becomes easier to further develop and improve a system like this, increasing its viability.Have you ever wondered what would happen if somebody could access your refrigerator? Might seem silly, but how about your front door's lock? With the ever increasing connected society, you might have to think about these questions sooner rather than later. The establishment of our connected society is heavily dependent on sensor nodes. There is currently no rigid way of loading the necessary cryptographic keys into these sensor nodes. Now, to enable these sensor nodes to communicate securely, we have studied alternative ways of using your smartphone to transmit these keys to the sensor nodes. In this thesis, we have shown alternative ways of using a smartphone to transmit cryptographic keys into sensor nodes. These alternative ways were achieved by using components not otherwise thought to be used for communication. For instance, we built prototypes that used the flashlight; the screen and the loudspeaker to successfully transmit the keys. Doing this we were able to make the transmission easy to use while at the same time upholding a high level of security. Currently, the sensor nodes have many protocols available to use for secure communications. However, these protocols often lack information about how one should load the sensor nodes with the keys, to begin with. In essence, they provide you with the car but not the key to start it. This is a problem that needs a concrete solution. The result of this thesis can be used as a guideline for further development of this type of solution. Our prototypes indicate that this type of solution is not only viable but can be secure as well. Using nothing more than a smartphone and small additions to the sensor nodes hardware. Briefly, the prototypes are built using an Android-powered smartphone as "key-transmitting device" while the receiving "sensor node" is equipped with a microphone or a photo-transistor. The additions to the receiver enable detection of both light and sound waves sent from the smartphone. Then, using the smartphone, the user is able to transmit data by blinking with the flashlight or screen; or sending tones with the loudspeaker, which the receiver interprets

Standardized low-power wireless communication technologies for distributed sensing applications

Recent standardization efforts on low-power wireless communication technologies, including time-slotted channel hopping (TSCH) and DASH7 Alliance Mode (D7AM), are starting to change industrial sensing applications, enabling networks to scale up to thousands of nodes whilst achieving high reliability. Past technologies, such as ZigBee, rooted in IEEE 802.15.4, and ISO 18000-7, rooted in frame-slotted ALOHA (FSA), are based on contention medium access control (MAC) layers and have very poor performance in dense networks, thus preventing the Internet of Things (IoT) paradigm from really taking off. Industrial sensing applications, such as those being deployed in oil refineries, have stringent requirements on data reliability and are being built using new standards. Despite the benefits of these new technologies, industrial shifts are not happening due to the enormous technology development and adoption costs and the fact that new standards are not well-known and completely understood. In this article, we provide a deep analysis of TSCH and D7AM, outlining operational and implementation details with the aim of facilitating the adoption of these technologies to sensor application developers.Peer ReviewedPostprint (published version

Supporting Cyber-Physical Systems with Wireless Sensor Networks: An Outlook of Software and Services

Sensing, communication, computation and control technologies are the essential building blocks of a cyber-physical system (CPS). Wireless sensor networks (WSNs) are a way to support CPS as they provide fine-grained spatial-temporal sensing, communication and computation at a low premium of cost and power. In this article, we explore the fundamental concepts guiding the design and implementation of WSNs. We report the latest developments in WSN software and services for meeting existing requirements and newer demands; particularly in the areas of: operating system, simulator and emulator, programming abstraction, virtualization, IP-based communication and security, time and location, and network monitoring and management. We also reflect on the ongoing efforts in providing dependable assurances for WSN-driven CPS. Finally, we report on its applicability with a case-study on smart buildings

Detecting malfunction in wireless sensor networks

The objective of this thesis is to detect malfunctioning sensors in wireless sensor networks. The ability to detect abnormality is critical to the security of any sensor network. However, the ability to detect a faulty wireless sensor is not trivial. Controlled repeatable experiments are difficult in wireless channels. A Redhat Linux. 7.0 Wireless Emulation Dynamic Switch software was used to solve this problem. Six nodes were configured with a node acting as a base station. The nodes were all part of a cell. This means that every node could communicate with all other nodes. A client-server program simulated the background traffic. Another program simulated a faulty node. A node was isolated as the faulty node while all other nodes were good. The experiment ran for several hours and the data was captured with tcpdump. The data was analyzed to conclusions based on a statistical comparison of good node versus bad node. The statistical delay on the good node was an average of 0.69 ms while the standard deviation was 0.49. This was much better than the delay on the bad node that was 0.225192 s with a standard deviation of 0.89. This huge difference in the delay indicated that the faulty node was detected statistically. A threshold value of I ms was chosen. The good node was within this value about 98% of the time. The bad node on the other hand was far out of this range and was definitely detected. The channel utilization data provided the same conclusion

Development of mobile agent framework in wireless sensor networks for multi-sensor collaborative processing

Recent advances in processor, memory and radio technology have enabled production of tiny, low-power, low-cost sensor nodes capable of sensing, communication and computation. Although a single node is resource constrained with limited power, limited computation and limited communication bandwidth, these nodes deployed in large number form a new type of network called the wireless sensor network (WSN). One of the challenges brought by WSNs is an efficient computing paradigm to support the distributed nature of the applications built on these networks considering the resource limitations of the sensor nodes. Collaborative processing between multiple sensor nodes is essential to generate fault-tolerant, reliable information from the densely-spatial sensing phenomenon. The typical model used in distributed computing is the client/server model. However, this computing model is not appropriate in the context of sensor networks. This thesis develops an energy-efficient, scalable and real-time computing model for collaborative processing in sensor networks called the mobile agent computing paradigm. In this paradigm, instead of each sensor node sending data or result to a central server which is typical in the client/server model, the information processing code is moved to the nodes using mobile agents. These agents carry the execution code and migrate from one node to another integrating result at each node. This thesis develops the mobile agent framework on top of an energy-efficient routing protocol called directed diffusion. The mobile agent framework described has been mapped to collaborative target classification application. This application has been tested in three field demos conducted at Twentynine palms, CA; BAE Austin, TX; and BBN Waltham, MA

Reconfigurable middleware architectures for large scale sensor networks

Wireless sensor networks, in an effort to be energy efficient, typically lack the high-level abstractions of advanced programming languages. Though strong, the dichotomy between these two paradigms can be overcome. The SENSIX software framework, described in this dissertation, uniquely integrates constraint-dominated wireless sensor networks with the flexibility of object-oriented programming models, without violating the principles of either. Though these two computing paradigms are contradictory in many ways, SENSIX bridges them to yield a dynamic middleware abstraction unifying low-level resource-aware task reconfiguration and high-level object recomposition. Through the layered approach of SENSIX, the software developer creates a domain-specific sensing architecture by defining a customized task specification and utilizing object inheritance. In addition, SENSIX performs better at large scales (on the order of 1000 nodes or more) than other sensor network middleware which do not include such unified facilities for vertical integration

An Investigation into the Performance Evaluation of Connected Vehicle Applications: From Real-World Experiment to Parallel Simulation Paradigm

A novel system was developed that provides drivers lane merge advisories, using vehicle trajectories obtained through Dedicated Short Range Communication (DSRC). It was successfully tested on a freeway using three vehicles, then targeted for further testing, via simulation. The failure of contemporary simulators to effectively model large, complex urban transportation networks then motivated further research into distributed and parallel traffic simulation. An architecture for a closed-loop, parallel simulator was devised, using a new algorithm that accounts for boundary nodes, traffic signals, intersections, road lengths, traffic density, and counts of lanes; it partitions a sample, Tennessee road network more efficiently than tools like METIS, which increase interprocess communications (IPC) overhead by partitioning more transportation corridors. The simulator uses logarithmic accumulation to synchronize parallel simulations, further reducing IPC. Analyses suggest this eliminates up to one-third of IPC overhead incurred by a linear accumulation model

Integração de funções de rede virtualizadas e funções de rede físicas

Network Functions Virtualization (NFV) and Software Defined Networking (SDN) have been in the center of network evolution, promising a more flexible and efficient way of managing networks through the on-demand instantiation of network functions (NFs) and reconfigurability of the network as necessary. Nevertheless, as new mechanisms are developed, such technologies require testing before their adoption into real-world deployments. This is where this dissertation contributes, by proposing and evaluating a system architecture that integrates a physical wireless testbed with a cloud-based environment. This allows physical wireless nodes to become part of the cloud environment, enabling its use and configuration as virtual NFs (VNFs). Results showcased the system feasibility, with the testbed being able to instantiate on-demand virtual and physical NFs, in the physical wireless nodes and in an OpenStack data-center.A Virtualização de Funções de Rede e as Redes Definidas por Software têm estado no centro da evolução das redes, prometendo uma forma mais flexível e eficiente de as gerenciar através da instanciação on-demand de Funções de Rede e da sua reconfiguração conforme o necessário. No entanto, à medida que novos mecanismos são desenvolvidos, é também necessário a realização de testes sobre estas tecnologias antes destas serem adotadas em implementações em contexto real. É aqui que esta dissertação contribui, propondo e avaliando uma arquitetura de sistema que integra um testbed físico sem fios, com um ambiente baseado em nuvem. Isto permite que os nós sem fios físicos se tornem parte do ambiente de nuvem, permitindo o seu uso e configuração como Funções de Rede Virtuais. Os resultados demonstraram a viabilidade do sistema, dada a capacidade da testbed em instanciar Funções de Rede virtuais e físicas quando requisitadas tanto nos nós sem fios físicos quanto no servidor OpenStack.Mestrado em Engenharia Eletrónica e Telecomunicaçõe