Mission-Critical Communications from LMR to 5G: a Technology Assessment approach for Smart City scenarios

Radiocommunication networks are one of the main support tools of agencies that carry out actions in Public Protection & Disaster Relief (PPDR), and it is necessary to update these communications technologies from narrowband to broadband and integrated to information technologies to have an effective action before society. Understanding that this problem includes, besides the technical aspects, issues related to the social context to which these systems are inserted, this study aims to construct scenarios, using several sources of information, that helps the managers of the PPDR agencies in the technological decisionmaking process of the Digital Transformation of Mission-Critical Communication considering Smart City scenarios, guided by the methods and approaches of Technological Assessment (TA).As redes de radiocomunicações são uma das principais ferramentas de apoio dos órgãos que realizam ações de Proteção Pública e Socorro em desastres, sendo necessário atualizar essas tecnologias de comunicação de banda estreita para banda larga, e integra- las às tecnologias de informação, para se ter uma atuação efetiva perante a sociedade . Entendendo que esse problema inclui, além dos aspectos técnicos, questões relacionadas ao contexto social ao qual esses sistemas estão inseridos, este estudo tem por objetivo a construção de cenários, utilizando diversas fontes de informação que auxiliem os gestores destas agências na tomada de decisão tecnológica que envolve a transformação digital da Comunicação de Missão Crítica considerando cenários de Cidades Inteligentes, guiado pelos métodos e abordagens de Avaliação Tecnológica (TA)

A Survey on Mobile Edge Computing for Video Streaming : Opportunities and Challenges

5G communication brings substantial improvements in the quality of service provided to various applications by achieving higher throughput and lower latency. However, interactive multimedia applications (e.g., ultra high definition video conferencing, 3D and multiview video streaming, crowd-sourced video streaming, cloud gaming, virtual and augmented reality) are becoming more ambitious with high volume and low latency video streams putting strict demands on the already congested networks. Mobile Edge Computing (MEC) is an emerging paradigm that extends cloud computing capabilities to the edge of the network i.e., at the base station level. To meet the latency requirements and avoid the end-to-end communication with remote cloud data centers, MEC allows to store and process video content (e.g., caching, transcoding, pre-processing) at the base stations. Both video on demand and live video streaming can utilize MEC to improve existing services and develop novel use cases, such as video analytics, and targeted advertisements. MEC is expected to reshape the future of video streaming by providing ultra-reliable and low latency streaming (e.g., in augmented reality, virtual reality, and autonomous vehicles), pervasive computing (e.g., in real-time video analytics), and blockchain-enabled architecture for secure live streaming. This paper presents a comprehensive survey of recent developments in MEC-enabled video streaming bringing unprecedented improvement to enable novel use cases. A detailed review of the state-of-the-art is presented covering novel caching schemes, optimal computation offloading, cooperative caching and offloading and the use of artificial intelligence (i.e., machine learning, deep learning, and reinforcement learning) in MEC-assisted video streaming services.publishedVersionPeer reviewe

처프 신호를 이용한 음파 통신 기법 연구

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2014. 8. 최성현.Todays smart devices such as smartphones and tablet/wearable PCs are equipped with voice user interface (UI) in order to support intuitive command input from users. Speakers and microphones of the voice UI are generally used to play and record human voice and/or environmental sound, respectively. Accordingly, various aerial acoustic communication techniques have been introduced to utilize the voice UI as an additional communication interface beyond WiFi and/or Bluetooth. Smart devices are especially suitable for the aerial acoustic communication since the application processor (AP) of smart devices can process the sound to embed or fetch information in it. That is, smart devices work similar to software defined radio platform. The aerial acoustic communication is also very versatile as any audio interface can be utilized as a communication interface. In this dissertation, we propose an aerial acoustic communication technique using inaudible chirp signal as well as corresponding receiver architecture for smart devices. We additionally introduce the applications of the proposed communication technique in indoor environments. We begin the receiver design for aerial acoustic communication by measuring the characteristics of indoor acoustic channel, composed of speaker, air-medium, and microphone. Our experimental research reveals that the indoor acoustic channel typically has long delay spread (approximately 40 msec), and it is very frequency-selective due to the frequency response of audio interfaces. We also show that legacy physical layer (PHY) modulation schemes such as phase/frequency shift keying (PSK/FSK) are likely to fail in this indoor acoustic channel, especially in long communication scenarios, due mainly to the instability of local oscillator and frequency selectivity of audio interfaces. In order to resolve the above-mentioned problems, we use chirp signals for the aerial acoustic communication. The proposed acoustic receiver supports long-range communication independent of the device characteristics over the severely frequency-selective acoustic channel with large delay spread. The chirp signal has time-varying frequency with a specific frequency sweeping rate. The chirp signal was widely used for radar applications due to its capability of resolving multi-path propagation. However, this dissertation is the first study of adopting chirp signal in aerial acoustic communications for smart devices. The proposed receiver architecture of chirp binary orthogonal keying (BOK) can be easily implemented via fast Fourier transform (FFT) in smart devices application layer. Via extensive experimental results, we verify that the proposed chirp signal can deliver data at 16 bps up to 25 m distance in typical indoor environments, which is drastically extended compared to the few meters of previous research. The data rate of 16 bps is enough to deliver short identification (ID) in indoor environments. The exemplary applications with this short ID can be multimedia content recognition and indoor location tracking. The low data rate, however, might be a huddle of the proposed system to be applied to the services that require high data rate. We design a backend server architecture in order to compensate for the low data rate and widen the application extent of the proposed receiver. The smart devices can send queries in order to refer to the backend server for additional information that is related with the received ID. We also propose an energy-efficient recording and processing method for the acoustic signal detection. Note that it would consume huge amount of energy if the smart devices contiguously sensed the acoustic signal for 24 hours. The smart devices instead control the sensing (i.e., recording) timing so that it is activated only when there exists chirp signal. This can drastically extend the battery lifetime by removing unnecessary signal processing. We also present two application examples of the proposed receiver, namely, (1) TV content recognition, and (2) indoor location tracking, including technical discussions on their implementations. Experiments and field tests validate the feasibility of the proposed aerial acoustic communication in practical environments.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Acoustic communication . . . . . . . . . . . . . . . . . 1 1.1.1 Underwater acoustic communication . . . . . 2 1.1.2 Aerial acoustic communication . . . . . . . . . . 3 1.2 Overview of Existing Approaches . . . . . . . . . . . 5 1.2.1 Indoor Location Tracking . . . . . . . . . . . . . . . 5 1.2.2 Data Communication using Acoustic Signal . 7 1.2.3 Commercial Services . . . . . . . . . . . . . . . . . . 9 1.2.4 Limitations of Previous Work . . . . . . . . . . . 10 1.3 Main Contributions . . . . . . . . . . . . . . . . . . . . . 11 1.3.1 Acoustic Channel and PHY Analysis . . . . . . 12 1.3.2 Receiver Design for Acoustic Chirp BOK . . . 12 1.3.3 Applications of Chirp BOK Receiver . . . . . . 13 1.4 Organization of the Dissertation . . . . . . . . . . 13 2 Acoustic Channel and PHY Analysis . . . . . . . . . . 15 2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.2 Characteristics of Indoor Acoustic Channel . . 18 2.2.1 Hearing Threshold of Human . . . . . . . . . . . 18 2.2.2 Frequency Response of Various Audio Interfaces . 21 2.2.3 Delay Spread of Acoustic Channel . . . . . . . . 25 2.3 Revisit of Existing Modulation Schemes . . . . . . 26 2.3.1 Case Study: Phase Shift Keying . . . . . . . . . . 28 2.3.2 Case Study: Frequency Shift Keying . . . . . . . 35 2.3.3 Chirp Binary Orthogonal Keying (BOK) . . . . 40 2.4 Performance Evaluation of PHY Modulation Schemes . 42 2.4.1 Experimental Environment . . . . . . . . . . . . . . 44 2.4.2 PSK Demodulator . . . . . . . . . . . . . . . . . . . . . 44 2.4.3 FSK Demodulator . . . . . . . . . . . . . . . . . . . . . 45 2.4.4 BER of PHY Modulation Schemes . . . . . . . . . 46 2.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 3 Receiver Design for Acoustic Chirp BOK . . . . . . . 49 3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 3.2 Chirp Signals and Matched Filter Receiver . . . . . 51 3.2.1 Notation of Chirp Signals . . . . . . . . . . . . . . . 51 3.2.2 Matched Filter and FFT . . . . . . . . . . . . . . . . . 53 3.2.3 Envelope Detection of Chirp Auto Correlation . 55 3.3 System Design and Receiver Architecture . . . . . . 59 3.3.1 Frame and Symbol Design . . . . . . . . . . . . . . . 60 3.3.2 Signal Reception Process . . . . . . . . . . . . . . . . 63 3.3.3 Receiver Architecture . . . . . . . . . . . . . . . . . . . 65 3.3.4 Symbol combining for BER enhancement . . . . 68 3.4 Performance Evaluation of Chirp BOK Receiver . . 73 3.4.1 Experimental Environment . . . . . . . . . . . . . . . . 74 3.4.2 Transmission Range in Indoor Environment . . . 74 3.4.3 Multi-path Resolution Capability of Chirp Signal . 75 3.4.4 Symbol Sampling and Doppler Shift . . . . . . . . . 82 3.4.5 Selective combining . . . . . . . . . . . . . . . . . . . . . 85 3.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 4 Applications of Chirp BOK Receiver . . . . . . . . . . . . . . 90 4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 4.2 Backend Server Architecture . . . . . . . . . . . . . . . . . . 93 4.2.1 Implementation of Backend Server . . . . . . . . . . 93 4.2.2 Operation of Backend Server . . . . . . . . . . . . . . 95 4.3 Low Power Operation for Smart Devices . . . . . . . . 98 4.3.1 Reception Process of Chirp BOK receiver . . . . . . 98 4.3.2 Revisit of Signal Detection in Wireless Communications ... 100 4.3.3 Chirp Signal Detection using PSD . . . . . . . . . . . 102 4.3.4 Performance Evaluation of Signal Detection Algorithm . 105 4.4 Applications of Chirp BOK Receiver and Feasibility Test . . 110 4.4.1 TV Content Recognition . . . . . . . . . . . . . . . . . . . 111 4.4.2 Indoor Location Tracking in Seoul Subway . . . . . 114 4.4.3 Device to Device Communication . . . . . . . . . . . . 118 4.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120 5 Conclusion and Future Work . . . . . . . . . . . . . . . . . . . 123 5.1 Research Contributions . . . . . . . . . . . . . . . . . . . . . . 123 5.2 Future Work and Concluding Remark . . . . . . . . . . 125 Abstract (In Korean) . . . . . . . . . . . . . . . . . . . . . . . . 136Docto

Results analysis and validation - D5.3

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

Social, Private, and Trusted Wearable Technology under Cloud-Aided Intermittent Wireless Connectivity

There has been an unprecedented increase in the use of smart devices globally, together with novel forms of communication, computing, and control technologies that have paved the way for a new category of devices, known as high-end wearables. While massive deployments of these objects may improve the lives of people, unauthorized access to the said private equipment and its connectivity is potentially dangerous. Hence, communication enablers together with highly-secure human authentication mechanisms have to be designed.In addition, it is important to understand how human beings, as the primary users, interact with wearable devices on a day-to-day basis; usage should be comfortable, seamless, user-friendly, and mindful of urban dynamics. Usually the connectivity between wearables and the cloud is executed through the user’s more power independent gateway: this will usually be a smartphone, which may have potentially unreliable infrastructure connectivity. In response to these unique challenges, this thesis advocates for the adoption of direct, secure, proximity-based communication enablers enhanced with multi-factor authentication (hereafter refereed to MFA) that can integrate/interact with wearable technology. Their intelligent combination together with the connection establishment automation relying on the device/user social relations would allow to reliably grant or deny access in cases of both stable and intermittent connectivity to the trusted authority running in the cloud.The introduction will list the main communication paradigms, applications, conventional network architectures, and any relevant wearable-specific challenges. Next, the work examines the improved architecture and security enablers for clusterization between wearable gateways with a proximity-based communication as a baseline. Relying on this architecture, the author then elaborates on the social ties potentially overlaying the direct connectivity management in cases of both reliable and unreliable connection to the trusted cloud. The author discusses that social-aware cooperation and trust relations between users and/or the devices themselves are beneficial for the architecture under proposal. Next, the author introduces a protocol suite that enables temporary delegation of personal device use dependent on different connectivity conditions to the cloud.After these discussions, the wearable technology is analyzed as a biometric and behavior data provider for enabling MFA. The conventional approaches of the authentication factor combination strategies are compared with the ‘intelligent’ method proposed further. The assessment finds significant advantages to the developed solution over existing ones.On the practical side, the performance evaluation of existing cryptographic primitives, as part of the experimental work, shows the possibility of developing the experimental methods further on modern wearable devices.In summary, the set of enablers developed here for wearable technology connectivity is aimed at enriching people’s everyday lives in a secure and usable way, in cases when communication to the cloud is not consistently available

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

Improved planning and resource management in next generation green mobile communication networks

In upcoming years, mobile communication networks will experience a disruptive reinventing process through the deployment of post 5th Generation (5G) mobile networks. Profound impacts are expected on network planning processes, maintenance and operations, on mobile services, subscribers with major changes in their data consumption and generation behaviours, as well as on devices itself, with a myriad of different equipment communicating over such networks. Post 5G will be characterized by a profound transformation of several aspects: processes, technology, economic, social, but also environmental aspects, with energy efficiency and carbon neutrality playing an important role. It will represent a network of networks: where different types of access networks will coexist, an increasing diversity of devices of different nature, massive cloud computing utilization and subscribers with unprecedented data-consuming behaviours. All at greater throughput and quality of service, as unseen in previous generations. The present research work uses 5G new radio (NR) latest release as baseline for developing the research activities, with future networks post 5G NR in focus. Two approaches were followed: i) method re-engineering, to propose new mechanisms and overcome existing or predictably existing limitations and ii) concept design and innovation, to propose and present innovative methods or mechanisms to enhance and improve the design, planning, operation, maintenance and optimization of 5G networks. Four main research areas were addressed, focusing on optimization and enhancement of 5G NR future networks, the usage of edge virtualized functions, subscriber’s behavior towards the generation of data and a carbon sequestering model aiming to achieve carbon neutrality. Several contributions have been made and demonstrated, either through models of methodologies that will, on each of the research areas, provide significant improvements and enhancements from the planning phase to the operational phase, always focusing on optimizing resource management. All the contributions are retro compatible with 5G NR and can also be applied to what starts being foreseen as future mobile networks. From the subscriber’s perspective and the ultimate goal of providing the best quality of experience possible, still considering the mobile network operator’s (MNO) perspective, the different proposed or developed approaches resulted in optimization methods for the numerous problems identified throughout the work. Overall, all of such contributed individually but aggregately as a whole to improve and enhance globally future mobile networks. Therefore, an answer to the main question was provided: how to further optimize a next-generation network - developed with optimization in mind - making it even more efficient while, simultaneously, becoming neutral concerning carbon emissions. The developed model for MNOs which aimed to achieve carbon neutrality through CO2 sequestration together with the subscriber’s behaviour model - topics still not deeply focused nowadays – are two of the main contributions of this thesis and of utmost importance for post-5G networks.Nos próximos anos espera-se que as redes de comunicações móveis se reinventem para lá da 5ª Geração (5G), com impactos profundos ao nível da forma como são planeadas, mantidas e operacionalizadas, ao nível do comportamento dos subscritores de serviços móveis, e através de uma miríade de dispositivos a comunicar através das mesmas. Estas redes serão profundamente transformadoras em termos tecnológicos, económicos, sociais, mas também ambientais, sendo a eficiência energética e a neutralidade carbónica aspetos que sofrem uma profunda melhoria. Paradoxalmente, numa rede em que coexistirão diferentes tipos de redes de acesso, mais dispositivos, utilização massiva de sistema de computação em nuvem, e subscritores com comportamentos de consumo de serviços inéditos nas gerações anteriores. O trabalho desenvolvido utiliza como base a release mais recente das redes 5G NR (New Radio), sendo o principal focus as redes pós-5G. Foi adotada uma abordagem de "reengenharia de métodos” (com o objetivo de propor mecanismos para resolver limitações existentes ou previsíveis) e de “inovação e design de conceitos”, em que são apresentadas técnicas e metodologias inovadoras, com o principal objetivo de contribuir para um desenho e operação otimizadas desta geração de redes celulares. Quatro grandes áreas de investigação foram endereçadas, contribuindo individualmente para um todo: melhorias e otimização generalizada de redes pós-5G, a utilização de virtualização de funções de rede, a análise comportamental dos subscritores no respeitante à geração e consumo de tráfego e finalmente, um modelo de sequestro de carbono com o objetivo de compensar as emissões produzidas por esse tipo de redes que se prevê ser massiva, almejando atingir a neutralidade carbónica. Como resultado deste trabalho, foram feitas e demonstradas várias contribuições, através de modelos ou metodologias, representando em cada área de investigação melhorias e otimizações, que, todas contribuindo para o mesmo objetivo, tiveram em consideração a retro compatibilidade e aplicabilidade ao que se prevê que sejam as futuras redes pós 5G. Focando sempre na perspetiva do subscritor da melhor experiência possível, mas também no lado do operador de serviço móvel – que pretende otimizar as suas redes, reduzir custos e maximizar o nível de qualidade de serviço prestado - as diferentes abordagens que foram desenvolvidas ou propostas, tiveram como resultado a resolução ou otimização dos diferentes problemas identificados, contribuindo de forma agregada para a melhoria do sistema no seu todo, respondendo à questão principal de como otimizar ainda mais uma rede desenvolvida para ser extremamente eficiente, tornando-a, simultaneamente, neutra em termos de emissões de carbono. Das principais contribuições deste trabalho relevam-se precisamente o modelo de compensação das emissões de CO2, com vista à neutralidade carbónica e um modelo de análise comportamental dos subscritores, dois temas ainda pouco explorados e extremamente importantes em contexto de redes futuras pós-5G

Models and Methods for Network Selection and Balancing in Heterogeneous Scenarios

The outbreak of 5G technologies for wireless communications can be considered a response to the need for widespread coverage, in terms of connectivity and bandwidth, to guarantee broadband services, such as streaming or on-demand programs offered by the main television networks or new generation services based on augmented and virtual reality (AR / VR). The purpose of the study conducted for this thesis aims to solve two of the main problems that will occur with the outbreak of 5G, that is, the search for the best possible connectivity, in order to offer users the resources necessary to take advantage of the new generation services, and multicast as required by the eMBMS. The aim of the thesis is the search for innovative algorithms that will allow to obtain the best connectivity to offer users the resources necessary to use the 5G services in a heterogeneous scenario. Study UF that allows you to improve the search for the best candidate network and to achieve a balance that allows you to avoid congestion of the chosen networks. To achieve these two important focuses, I conducted a study on the main mathematical methods that made it possible to select the network based on QoS parameters based on the type of traffic made by users. A further goal was to improve the computational computation performance they present. Furthermore, I carried out a study in order to obtain an innovative algorithm that would allow the management of multicast. The algorithm that has been implemented responds to the needs present in the eMBMS, in realistic scenarios