On demonstrating spectrum selection functionality for opportunistic networks

This paper presents a testbed platform to demonstrate and validate spectrum opportunity identification and spectrum selection functionalities in Opportunistic Networks (ONs). The hardware component of the testbed is based on reconfigurable devices able to transmit and receive data at different operating frequencies, which are dynamically configured. The software component has been developed to perform the creation and maintenance of ON radio links, including spectrum opportunity identification and selection decision making as well as all the necessary signaling to support the ON operation. Therefore, the presented platform provides a powerful tool for testing different algorithms in real operational radio environments under various interference conditions, thus enabling to gain deeper insight into the performance of algorithmic solutions, beyond the purely theoretical analyses based on models and/or simulations. Results presented in the paper validate the implementation conducted at the laboratory and illustrate the reconfigurability capabilities of the ON links under different conditions.Peer ReviewedPostprint (published version

Results analysis and validation - D5.3

Deliverable D5.3 del projecte OneFITPostprint (author’s final draft

Validation platform specification – D5.1

Deliverable D5.1 del projecte Europeu OneFIT (ICT-2009-257385)The present deliverable introduces the OneFIT Proof-of-Concept (PoC) Architecture which will be used as a basis for the validation platform development throughout the project. This PoC Architecture proposal is validated by identifying the roles of the various components in the framework of the OneFIT Scenarios as derived and detailed in WP2. The applied methodology ensures that all required features are appropriately considered. Furthermore, the hardware components available to the project are detailed which are the basis for the development of an integrated validation platform. Their role is highlighted by an instantiation step which maps the PoC Architecture components to the identified hardware components. Finally, a scenario instantiation is derived which illustrates the role of the various hardware components for the validation of selected OneFIT scenarios.Postprint (published version

Implementation of cognitive radio networks to evaluate spectrum management strategies in real-time

This paper illustrates a Universal Software Radio Peripheral (USRP)-based real-time testbed that is able to evaluate different spectrum management solutions that exploit the Cognitive Radio (CR) paradigm. The main objective of this testbed is to provide an accurate and realistic platform by which the performance of innovative spectrum management solutions for a wide set of scenarios and use cases in the context of Opportunistic Networks (ONs) and Cognitive Radio Networks (CRNs) can be entirely validated and assessed before their implementation in real systems. Real-time platforms are essential to carry out significant studies and to accurately assess the performance of innovative solutions before their implementation in the real world. This work provides a comprehensive description of the testbed, highlighting many interesting implementation details and illustrating its applicability for different studies that rely on the CR paradigm. Then, a particular application in a realistic Digital Home (DH) scenario is also illustrated, which allows demonstrating the effectiveness of the real-time testbed and assessing its practicality in terms of user-perceived end-to-end Quality of Experience (QoE) in a realistic environment.Peer ReviewedPostprint (author's final draft

Cognitive management frameworks and spectrum management strategies exploiting cognitive radio paradigm

Cognitive Radio (CR) paradigm represents an innovative solution to mitigate the spectrum scarcity problem by enabling Dynamic Spectrum Access (DSA), defined in order to conciliate the existing conflicts between the ever-increasing spectrum demand growth and the currently inefficient spectrum utilization. The basic idea of DSA is to provide proper solutions that allow sharing radio spectrum among several radio communication systems with sake of optimizing the overall spectrum utilization. This dissertation addressed the problem of modelling cognitive management frameworks that provide innovative strategies for spectrum management suitable to different scenarios and use cases in the context of DSA/CR Networks (CRNs). The first solution presented in this dissertation initially addressed the development of a framework that provides spectrum management strategies for Opportunistic Networks (ONs) defined as extended infrastructures created temporarily to serve specific regions following the policies dictated by the operator. The development of systems based on the CR paradigm to support the ONs is considered a key aspect to allow autonomous decisions and reconfiguration ability mechanisms because of the temporarily nature of these networks and the highly dynamic nature of the radio environment. Then, in order to expand the design of cognitive management frameworks providing spectrum management solutions that have applicability in a number of different scenarios and use cases, a cognitive management framework that exploits the Partially Observable Markov Decision Process (POMDP) concept has been proposed to combine the CR capabilities of radio environment awareness with a statistical characterization of the system dynamic. Finally, the framework based on POMDPs has been further extended with new functionalities able to characterize the environment dynamic through long-term predictions carried out exploiting the so-called belief vector. These frameworks as a whole aimed at demonstrating that a reliable characterization of the radio environment that combines awareness of its surrounding with a statistical evaluation of the system dynamics is able to guarantee an effcient utilization of the available spectrum resources. From a methodological point of view, the development and assessment of the proposed cognitive management frameworks and the corresponding spectrum management solutions involved analytical studies, system-level simulations and a real-time platform implementation. Overall, the research conducted in the context of this dissertation has revealed that proper cognitive management functionalities can be extremely beneficial to support spectrum management in a wide variety of scenarios and use cases.El paradigma de radio cognitiva (CR) representa una solución innovadora para mitigar el problema de escasez de los recursos radio, permitiendo el acceso dinámico al espectro (DSA), definido con el fin de conciliar los conflictos existentes entre el crecimiento de la demanda de espectro, cada vez mayor, y la utilización de los recursos radio actualmente ineficiente. La idea básica del DSA es proporcionar soluciones adecuadas que permitan compartir el espectro radioeléctrico entre varios sistemas de comunicaciones radio con el objetivo de optimizar la utilización general del espectro. Esta tesis doctoral aborda el problema de la modelización de marcos de gestión cognitiva que proporcionan estrategias innovadoras y adecuadas para la gestión del espectro en diferentes escenarios y casos de uso en el contexto de las redes de radio cognitiva (CRN). La primera solución que se presenta en esta tesis aborda inicialmente el desarrollo de un marco que ofrece estrategias de gestión del espectro para redes oportunistas (ONs) definidas como infraestructuras extendidas, creadas temporalmente para servir a regiones específicas siguiendo las políticas dictadas por el operador. Debido a la naturaleza temporal de estas redes y a la naturaleza altamente dinámica del entorno radio, el desarrollo de sistemas basados en el paradigma de CR para apoyar las ONs se considera un aspecto clave que permite decisiones autónomas y mecanismos de reconfiguración. Luego, con el fin de ampliar el diseño de los marcos de gestión cognitiva para proporcionar soluciones de gestión del espectro con aplicabilidad en una serie de diferentes escenarios y casos de uso, se ha propuesto un marco de gestión cognitiva que explota el concepto de Partially Observable Markov Decision Process (POMDP) para combinar las capacidades de conocimiento del entorno radio del CR, con una caracterización estadística de la dinámica del sistema. Finalmente, el marco basado en el POMDP se ha ampliado con nuevas funcionalidades capaces de caracterizar el entorno dinámico a través de predicciones a largo plazo llevadas a cabo explotando el concepto de belief vector. Estos marcos en su conjunto tienen el objetivo de demostrar que una caracterización fiable del entorno radio que combina el conocimiento de su entorno con una evaluación estadística de la dinámica del sistema, es capaz de garantizar una utilización eficiente de los recursos disponibles del espectro. Desde un punto de vista de la metodología, el desarrollo y la evaluación de los marcos de gestión cognitiva propuestos y las correspondientes soluciones de gestión del espectro han involucrado estudios analíticos, simulaciones y la implementación de una plataforma que permite evaluaciones en tiempo real. En general, la investigación llevada a cabo en el contexto de esta tesis doctoral ha revelado que funcionalidades adecuadas de gestión cognitiva pueden ser extremadamente eficientes para apoyar la gestión del espectro en una amplia variedad de escenarios y casos de estudio

Results analysis and validation - D5.3

This deliverable describes the validation processes followed to assess the performance of the algorithms and protocols for the operator governed opportunistic networking as defined in the OneFIT Project. Therefore, this document includes the description of the set-up of the different validation platforms, the design of the test plans for each one of them, and the analysis of the results obtained from the tests. A per-scenario approach rather than a per-platform approach has been followed, so an additional analysis has been performed, gathering the results related to each scenario, in order to validate the premises stated to each one of them. The OneFIT concept has been therefore validated for all foreseen business scenarios

A Test Methodology for Evaluating Cognitive Radio Systems

The cognitive radio field currently lacks a standardized test methodology that is repeatable, flexible, and effective across multiple cognitive radio architectures. Furthermore, the cognitive radio field lacks a suitable framework that allows testing of an integrated cognitive radio system and not solely specific components. This research presents a cognitive radio test methodology, known as CRATM, to address these issues. CRATM proposes to use behavior-based testing, in which cognition may be measured by evaluating both primary user and secondary user performance. Data on behavior based testing is collected and evaluated. Additionally, a unique means of measuring secondary user interference to the primary user is employed by direct measurement of primary user performance. A secondary user pair and primary user radio pair are implemented using the Wireless Open-Access Research platform and WARPLab software running in MATLAB. The primary user is used to create five distinct radio frequency environments utilizing narrowband, wideband, and non-contiguous waveforms. The secondary user response to the primary user created environments is measured. The secondary user implements a simple cognitive engine that incorporates energy-detection spectrum sensing. The effect of the cognitive engine on both secondary user and primary user performance is measured and evaluated

Upper-Confidence Bound for Channel Selection in LPWA Networks with Retransmissions

In this paper, we propose and evaluate different learning strategies based on Multi-Arm Bandit (MAB) algorithms. They allow Internet of Things (IoT) devices to improve their access to the network and their autonomy, while taking into account the impact of encountered radio collisions. For that end, several heuristics employing Upper-Confident Bound (UCB) algorithms are examined, to explore the contextual information provided by the number of retransmissions. Our results show that approaches based on UCB obtain a significant improvement in terms of successful transmission probabilities. Furthermore, it also reveals that a pure UCB channel access is as efficient as more sophisticated learning strategies.Comment: The source code (MATLAB or Octave) used for the simula-tions and the figures is open-sourced under the MIT License, atBitbucket.org/scee\_ietr/ucb\_smart\_retran