Reversing The Meaning of Node Connectivity for Content Placement in Networks of Caches

It is a widely accepted heuristic in content caching to place the most popular content at the nodes that are the best connected. The other common heuristic is somewhat contradictory, as it places the most popular content at the edge, at the caching nodes nearest the users. We contend that neither policy is best suited for caching content in a network and propose a simple alternative that places the most popular content at the least connected node. Namely, we populate content first at the nodes that have the lowest graph centrality over the network topology. Here, we provide an analytical study of this policy over some simple topologies that are tractable, namely regular grids and trees. Our mathematical results demonstrate that placing popular content at the least connected nodes outperforms the aforementioned alternatives in typical conditions

Evaluating Caching Mechanisms In Future Internet Architectures

MEng thesisThis thesis seeks to test and evaluate the effects of in-­network storage in novel proposed Internet architectures in terms of their performance. In a world where more and more people are mobile and connected to the Internet, we look at how the added variable of user mobility can affect how these architectures perform under different loads. Evaluating the effects of in­-network storage and caching in these novel architectures will provide another facet to understanding how viable of an alternative they would be to the current TCP/IP paradigm of today's Internet. In Named Data Networking, where the storage is used to directly cache content, we see its use of storage impact the locality of where things are, while in MobilityFirst, where storage is used to cache chunks to provide robust delivery, we look at how its different layers work together in a mobility event

Cooperative mechanisms for information dissemination and retrieval in networks with autonomous nodes

Αυτή η διατριβή συνεισφέρει στη βιβλιογραφία με το να προτείνει και να μοντελοποιήσει καινοτόμους αλγορίθμους και σχήματα που επιτρέπουν στις διεργασίες διάδοσης και ανάκτησης πληροφοριών – και γενικότερα της διαχείρισης περιεχομένου – να εκτελεστούν πιο αποτελεσματικά σε ένα σύγχρονο περιβάλλον δικτύωσης. Εκτός από τη διάδοση και ανάκτηση των πληροφοριών, άλλες πτυχές της διαχείρισης περιεχομένου που εξετάζουμε είναι η αποθήκευση και η κατηγοριοποίηση. Η πιο σημαντική πρόκληση που αφορά πολλά από τα σχήματα που προτείνονται στην παρούσα εργασία είναι η ανάγκη να διαχειριστούν την αυτονομία των κόμβων, διατηρώντας παράλληλα τον κατανεμημένο, καθώς και τον ανοικτό χαρακτήρα του συστήματος. Κατά το σχεδιασμό κατανεμημένων μηχανισμών σε δίκτυα με αυτόνομους κόμβους, ένα σημαντικό επίσης Ζητούμενο είναι να δημιουργηθούν κίνητρα ώστε οι κόμβοι να συνεργάζονται κατά την εκτέλεση των καθηκόντων επικοινωνίας. Ένα καινούργιο χαρακτηριστικό των περισσοτέρων από τα προτεινόμενα σχήματα είναι η αξιοποίηση των κοινωνικών χαρακτηριστικών των κόμβων, εστιάζοντας στο πώς τα κοινά ενδιαφέροντα των κόμβων μπορούν να αξιοποιηθούν για τη βελτίωση της αποδοτικότητας στην επικοινωνία. Για την αξιολόγηση της απόδοσης των προτεινόμενων αλγορίθμων και σχημάτων, κυρίως αναπτύσσουμε μαθηματικά στοχαστικά μοντέλα και λαμβάνουμε αριθμητικά αποτελέσματα. Όπου είναι απαραίτητο, παρέχουμε αποτελέσματα προσομοίωσης που επαληθεύουν την ακρίβεια αυτών των μοντέλων. Πραγματικά ίχνη δικτύου χρησιμοποιούνται όπου θέλουμε να υποστηρίξουμε περαιτέρω τη λογική για την πρόταση ενός συγκεκριμένου σχήματος. Ένα βασικό εργαλείο για τη μοντελοποίηση και την ανάλυση των προβλημάτων συνεργασίας σε δίκτυα με αυτόνομους κόμβους είναι η θεωρία παιγνίων, η οποία χρησιμοποιείται σε μερικά τμήματα αυτής της διατριβής για να βοηθήσει στην εξακρίβωση της δυνατότητας διατήρησης της συνεργασίας μεταξύ των κόμβων στο δίκτυο. Με την αξιοποίηση των κοινωνικών χαρακτηριστικών των κόμβων, μπαίνουμε επίσης στον τομέα της ανάλυσης των κοινωνικών δικτύων, και χρησιμοποιούμε σχετικές μετρικές και τεχνικές ανάλυσης.This thesis contributes to the literature by proposing and modeling novel algorithms and schemes that allow the tasks of information dissemination and retrieval – and more generally of content management – to be performed more efficiently in a modern networking environment. Apart from information dissemination and retrieval, other aspects of content management we examine are content storage and classification. The most important challenge that will preoccupy many of the proposed schemes is the need to manage the autonomy of nodes while preserving the distributed, as well as the open nature of the system. In designing distributed mechanisms in networks with autonomous nodes, an important challenge is also to develop incentives for nodes to cooperate while performing communication tasks. A novel characteristic of most of the proposed schemes is the exploitation of social characteristics of nodes, focusing on how common interests of nodes can be used to improve communication efficiency. In order to evaluate the performance of the proposed algorithms and schemes, we mainly develop mathematical stochastic models and obtain numerical results. Where it is deemed necessary, we provide simulation results that verify the accuracy of these models. Real network traces are used where we want to further support the rationale for proposing a certain scheme. A key tool for modeling and analyzing cooperation problems in networks with autonomous nodes is game theory, and it is used in parts of this thesis to help identify the feasibility of sustaining cooperation between nodes in the network. By exploiting social characteristics of nodes, we also enter the field of social network analysis, and use related metrics and techniques

Compilation Optimizations to Enhance Resilience of Big Data Programs and Quantum Processors

Modern computers can experience a variety of transient errors due to the surrounding environment, known as soft faults. Although the frequency of these faults is low enough to not be noticeable on personal computers, they become a considerable concern during large-scale distributed computations or systems in more vulnerable environments like satellites. These faults occur as a bit flip of some value in a register, operation, or memory during execution. They surface as either program crashes, hangs, or silent data corruption (SDC), each of which can waste time, money, and resources. Hardware methods, such as shielding or error correcting memory (ECM), exist, though they can be difficult to implement, expensive, and may be limited to only protecting against errors in specific locations. Researchers have been exploring software detection and correction methods as an alternative, commonly trading either overhead in execution time or memory usage to protect against faults. Quantum computers, a relatively recent advancement in computing technology, experience similar errors on a much more severe scale. The errors are more frequent, costly, and difficult to detect and correct. Error correction algorithms like Shor’s code promise to completely remove errors, but they cannot be implemented on current noisy intermediate-scale quantum (NISQ) systems due to the low number of available qubits. Until the physical systems become large enough to support error correction, researchers instead have been studying other methods to reduce and compensate for errors. In this work, we present two methods for improving the resilience of classical processes, both single- and multi-threaded. We then introduce quantum computing and compare the nature of errors and correction methods to previous classical methods. We further discuss two designs for improving compilation of quantum circuits. One method, focused on quantum neural networks (QNNs), takes advantage of partial compilation to avoid recompiling the entire circuit each time. The other method is a new approach to compiling quantum circuits using graph neural networks (GNNs) to improve the resilience of quantum circuits and increase fidelity. By using GNNs with reinforcement learning, we can train a compiler to provide improved qubit allocation that improves the success rate of quantum circuits

Segurança e privacidade em terminologia de rede

Security and Privacy are now at the forefront of modern concerns, and drive a significant part of the debate on digital society. One particular aspect that holds significant bearing in these two topics is the naming of resources in the network, because it directly impacts how networks work, but also affects how security mechanisms are implemented and what are the privacy implications of metadata disclosure. This issue is further exacerbated by interoperability mechanisms that imply this information is increasingly available regardless of the intended scope. This work focuses on the implications of naming with regards to security and privacy in namespaces used in network protocols. In particular on the imple- mentation of solutions that provide additional security through naming policies or increase privacy. To achieve this, different techniques are used to either embed security information in existing namespaces or to minimise privacy ex- posure. The former allows bootstraping secure transport protocols on top of insecure discovery protocols, while the later introduces privacy policies as part of name assignment and resolution. The main vehicle for implementation of these solutions are general purpose protocols and services, however there is a strong parallel with ongoing re- search topics that leverage name resolution systems for interoperability such as the Internet of Things (IoT) and Information Centric Networks (ICN), where these approaches are also applicable.Segurança e Privacidade são dois topicos que marcam a agenda na discus- são sobre a sociedade digital. Um aspecto particularmente subtil nesta dis- cussão é a forma como atribuímos nomes a recursos na rede, uma escolha com consequências práticas no funcionamento dos diferentes protocols de rede, na forma como se implementam diferentes mecanismos de segurança e na privacidade das várias partes envolvidas. Este problema torna-se ainda mais significativo quando se considera que, para promover a interoperabili- dade entre diferentes redes, mecanismos autónomos tornam esta informação acessível em contextos que vão para lá do que era pretendido. Esta tese foca-se nas consequências de diferentes políticas de atribuição de nomes no contexto de diferentes protocols de rede, para efeitos de segurança e privacidade. Com base no estudo deste problema, são propostas soluções que, através de diferentes políticas de atribuição de nomes, permitem introdu- zir mecanismos de segurança adicionais ou mitigar problemas de privacidade em diferentes protocolos. Isto resulta na implementação de mecanismos de segurança sobre protocolos de descoberta inseguros, assim como na intro- dução de mecanismos de atribuiçao e resolução de nomes que se focam na protecçao da privacidade. O principal veículo para a implementação destas soluções é através de ser- viços e protocolos de rede de uso geral. No entanto, a aplicabilidade destas soluções extende-se também a outros tópicos de investigação que recorrem a mecanismos de resolução de nomes para implementar soluções de intero- perabilidade, nomedamente a Internet das Coisas (IoT) e redes centradas na informação (ICN).Programa Doutoral em Informátic

Fault and Defect Tolerant Computer Architectures: Reliable Computing With Unreliable Devices

This research addresses design of a reliable computer from unreliable device technologies. A system architecture is developed for a fault and defect tolerant (FDT) computer. Trade-offs between different techniques are studied and yield and hardware cost models are developed. Fault and defect tolerant designs are created for the processor and the cache memory. Simulation results for the content-addressable memory (CAM)-based cache show 90% yield with device failure probabilities of 3 x 10(-6), three orders of magnitude better than non fault tolerant caches of the same size. The entire processor achieves 70% yield with device failure probabilities exceeding 10(-6). The required hardware redundancy is approximately 15 times that of a non-fault tolerant design. While larger than current FT designs, this architecture allows the use of devices much more likely to fail than silicon CMOS. As part of model development, an improved model is derived for NAND Multiplexing. The model is the first accurate model for small and medium amounts of redundancy. Previous models are extended to account for dependence between the inputs and produce more accurate results

Cost Effective Routing Implementations for On-chip Networks

Arquitecturas de múltiples núcleos como multiprocesadores (CMP) y soluciones multiprocesador para sistemas dentro del chip (MPSoCs) actuales se basan en la eficacia de las redes dentro del chip (NoC) para la comunicación entre los diversos núcleos. Un diseño eficiente de red dentro del chip debe ser escalable y al mismo tiempo obtener valores ajustados de área, latencia y consumo de energía. Para diseños de red dentro del chip de propósito general se suele usar topologías de malla 2D ya que se ajustan a la distribución del chip. Sin embargo, la aparición de nuevos retos debe ser abordada por los diseñadores. Una mayor probabilidad de defectos de fabricación, la necesidad de un uso optimizado de los recursos para aumentar el paralelismo a nivel de aplicación o la necesidad de técnicas eficaces de ahorro de energía, puede ocasionar patrones de irregularidad en las topologías. Además, el soporte para comunicación colectiva es una característica buscada para abordar con eficacia las necesidades de comunicación de los protocolos de coherencia de caché. En estas condiciones, un encaminamiento eficiente de los mensajes se convierte en un reto a superar. El objetivo de esta tesis es establecer las bases de una nueva arquitectura para encaminamiento distribuido basado en lógica que es capaz de adaptarse a cualquier topología irregular derivada de una estructura de malla 2D, proporcionando así una cobertura total para cualquier caso resultado de soportar los retos mencionados anteriormente. Para conseguirlo, en primer lugar, se parte desde una base, para luego analizar una evolución de varios mecanismos, y finalmente llegar a una implementación, que abarca varios módulos para alcanzar el objetivo mencionado anteriormente. De hecho, esta última implementación tiene por nombre eLBDR (effective Logic-Based Distributed Routing). Este trabajo cubre desde el primer mecanismo, LBDR, hasta el resto de mecanismos que han surgido progresivamente.Rodrigo Mocholí, S. (2010). Cost Effective Routing Implementations for On-chip Networks [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/8962Palanci

Security plane for data authentication in information-centric networks

Orientadores: Maurício Ferreira Magalhães, Jussi KangasharjuTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: A segurança da informação é responsável pela proteção das informações contra o acesso nãoautorizado, uso, modificação ou a sua destruição. Com o objetivo de proteger os dados contra esses ataques de segurança, vários protocolos foram desenvolvidos, tais como o Internet Protocol Security (IPSEC) e o Transport Layer Security (TLS), provendo mecanismos de autenticação, integridade e confidencialidade dos dados para os usuários. Esses protocolos utilizam o endereço IP como identificador de hosts na Internet, tornando-o referência e identificador no estabelecimento de conexões seguras para a troca de dados entre aplicações na rede. Com o advento da Web e o aumento exponencial do consumo de conteúdos, como vídeos e áudios, há indícios da migração gradual do uso predominante da Internet, passando da ênfase voltada para a conexão entre hosts para uma ênfase voltada para a obtenção de conteúdo da rede, paradigma esse conhecido como information-centric networking. Nesse paradigma, usuários buscam por documentos e recursos na Internet sem se importarem com o conhecimento explícito da localização do conteúdo. Como consequência, o endereço IP que previamente era utilizado como ponto de referência do provedor de dados, torna-se meramente um identificador efêmero do local onde o conteúdo está armazenado, resultando em implicações para a autenticação correta dos dados. Nesse contexto, a simples autenticação de um endereço IP não garante a autenticidade dos dados, uma vez que o servidor identificado por um dado endereço IP não é necessariamente o endereço do produtor do conteúdo. No contexto de redes orientadas à informação, existem propostas na literatura que possibilitam a autenticação dos dados utilizando somente o conteúdo propriamente dito, como a utilização de assinaturas digitais por bloco de dado e a construção de árvores de hash sobre os blocos de dados. A ideia principal dessas abordagens é atrelar uma informação do provedor original do conteúdo nos blocos de dados transportados, por exemplo, uma assinatura digital, possibilitando a autenticação direta dos dados com o provedor, independentemente do host onde o dado foi obtido. Apesar do mecanismo citado anteriormente possibilitar tal verificação, esse procedimento é muito oneroso do ponto de vista de processamento, especialmente quando o número de blocos é grande, tornando-o inviável de ser utilizado na prática. Este trabalho propõe um novo mecanismo de autenticação utilizando árvores de hash com o objetivo de prover a autenticação dos dados de forma eficiente e explícita com o provedor original e, também, de forma independente do host onde os dados foram obtidos. Nesta tese, propomos duas técnicas de autenticação de dados baseadas em árvores de hash, chamadas de skewed hash tree (SHT) e composite hash tree (CHT), para a autenticação de dados em redes orientadas à informação. Uma vez criadas, parte dos dados de autenticação é armazenada em um plano de segurança e uma outra parte permanece acoplada ao dado propriamente dito, possibilitando a verificação baseada no conteúdo e não no host de origem. Além disso, essa tese apresenta o modelo formal, a especificação e a implementação das duas técnicas de árvore de hash para autenticação dos dados em redes de conteúdo através de um plano de segurança. Por fim, esta tese detalha a instanciação do modelo de plano de segurança proposto em dois cenários de autenticação de dados: 1) redes Peer-to-Peer e 2) autenticação paralela de dados sobre o HTTPAbstract: Information security is responsible for protecting information against unauthorized access, use, modification or destruction. In order to protect such data against security attacks, many security protocols have been developed, for example, Internet Protocol Security (IPSec) and Transport Layer Security (TLS), providing mechanisms for data authentication, integrity and confidentiality for users. These protocols use the IP address as host identifier on the Internet, making it as a reference and identifier during the establishment of secure connections for data exchange between applications on the network. With the advent of the Web and the exponential increase in content consumption (e.g., video and audio), there is an evidence of a gradual migration of the predominant usage of the Internet, moving the emphasis on the connection between hosts to the content retrieval from the network, which paradigm is known as information-centric networking. In this paradigm, users look for documents and resources on the Internet without caring about the explicit knowledge of the location of the content. As a result, the IP address that was used previously as a reference point of a data provider, becomes merely an ephemeral identifier of where the content is stored, resulting in implications for the correct authentication data. In this context, the simple authentication of an IP address does not guarantee the authenticity of the data, because a hosting server identified by a given IP address is not necessarily the same one that is producing the requested content. In the context of information-oriented networks, some proposals in the literature proposes authentication mechanisms based on the content itself, for example, digital signatures over a data block or the usage of hash trees over data blocks. The main idea of these approaches is to add some information from the original provider in the transported data blocks, for example, a digital signature, enabling data authentication directly with the original provider, regardless of the host where the data was obtained. Although the mechanism mentioned previously allows for such verification, this procedure is very costly in terms of processing, especially when the number of blocks is large, making it unfeasible in practice. This thesis proposes a new authentication mechanism using hash trees in order to provide efficient data authentication and explicitly with the original provider, and also independently of the host where the data were obtained. We propose two techniques for data authentication based on hash trees, called skewed hash tree (SHT) and composite hash tree (CHT), for data authentication in information-oriented networks. Once created, part of the authentication data is stored in a security plane and another part remains attached to the data itself, allowing for the verification based on content and not on the source host. In addition, this thesis presents the formal model, specification and implementation of two hash tree techniques for data authentication in information-centric networks through a security plane. Finally, this thesis details the instantiation of the security plane model in two scenarios of data authentication: 1) Peer-to-Peer and 2) parallel data authentication over HTTPDoutoradoEngenharia de ComputaçãoDoutor em Engenharia Elétric

Storing and managing data in a distributed hash table

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 83-90).Distributed hash tables (DHTs) have been proposed as a generic, robust storage infrastructure for simplifying the construction of large-scale, wide-area applications. For example, UsenetDHT is a new design for Usenet News developed in this thesis that uses a DHT to cooperatively deliver Usenet articles: the DHT allows a set of N hosts to share storage of Usenet articles, reducing their combined storage requirements by a factor of O(N). Usenet generates a continuous stream of writes that exceeds 1 Tbyte/day in volume, comprising over ten million writes. Supporting this and the associated read workload requires a DHT engineered for durability and efficiency. Recovering from network and machine failures efficiently poses a challenge for DHT replication maintenance algorithms that provide durability. To avoid losing the last replica, replica maintenance must create additional replicas when failures are detected. However, creating replicas after every failure stresses network and storage resources unnecessarily. Tracking the location of every replica of every object would allow a replica maintenance algorithm to create replicas only when necessary, but when storing terabytes of data, such tracking is difficult to perform accurately and efficiently. This thesis describes a new algorithm, Passing Tone, that maintains durability efficiently, in a completely decentralized manner, despite transient and permanent failures. Passing Tone nodes make replication decisions with just basic DHT routing state, without maintaining state about the number or location of extant replicas and without responding to every transient failure with a new replica. Passing Tone is implemented in a revised version of DHash, optimized for both disk and network performance.(cont.) A sample 12 node deployment of Passing Tone and UsenetDHT supports a partial Usenet feed of 2.5 Mbyte/s (processing over 80 Tbyte of data per year), while providing 30 Mbyte/s of read throughput, limited currently by disk seeks. This deployment is the first public DHT to store terabytes of data. These results indicate that DHT-based designs can successfully simplify the construction of large-scale, wide-area systems.by Emil Sit.Ph.D

Broadcast-oriented wireless network-on-chip : fundamentals and feasibility

Premi extraordinari doctorat UPC curs 2015-2016, àmbit Enginyeria de les TICRecent years have seen the emergence and ubiquitous adoption of Chip Multiprocessors (CMPs), which rely on the coordinated operation of multiple execution units or cores. Successive CMP generations integrate a larger number of cores seeking higher performance with a reasonable cost envelope. For this trend to continue, however, important scalability issues need to be solved at different levels of design. Scaling the interconnect fabric is a grand challenge by itself, as new Network-on-Chip (NoC) proposals need to overcome the performance hurdles found when dealing with the increasingly variable and heterogeneous communication demands of manycore processors. Fast and flexible NoC solutions are needed to prevent communication become a performance bottleneck, situation that would severely limit the design space at the architectural level and eventually lead to the use of software frameworks that are slow, inefficient, or less programmable. The emergence of novel interconnect technologies has opened the door to a plethora of new NoCs promising greater scalability and architectural flexibility. In particular, wireless on-chip communication has garnered considerable attention due to its inherent broadcast capabilities, low latency, and system-level simplicity. Most of the resulting Wireless Network-on-Chip (WNoC) proposals have set the focus on leveraging the latency advantage of this paradigm by creating multiple wireless channels to interconnect far-apart cores. This strategy is effective as the complement of wired NoCs at moderate scales, but is likely to be overshadowed at larger scales by technologies such as nanophotonics unless bandwidth is unrealistically improved. This dissertation presents the concept of Broadcast-Oriented Wireless Network-on-Chip (BoWNoC), a new approach that attempts to foster the inherent simplicity, flexibility, and broadcast capabilities of the wireless technology by integrating one on-chip antenna and transceiver per processor core. This paradigm is part of a broader hybrid vision where the BoWNoC serves latency-critical and broadcast traffic, tightly coupled to a wired plane oriented to large flows of data. By virtue of its scalable broadcast support, BoWNoC may become the key enabler of a wealth of unconventional hardware architectures and algorithmic approaches, eventually leading to a significant improvement of the performance, energy efficiency, scalability and programmability of manycore chips. The present work aims not only to lay the fundamentals of the BoWNoC paradigm, but also to demonstrate its viability from the electronic implementation, network design, and multiprocessor architecture perspectives. An exploration at the physical level of design validates the feasibility of the approach at millimeter-wave bands in the short term, and then suggests the use of graphene-based antennas in the terahertz band in the long term. At the link level, this thesis provides an insightful context analysis that is used, afterwards, to drive the design of a lightweight protocol that reliably serves broadcast traffic with substantial latency improvements over state-of-the-art NoCs. At the network level, our hybrid vision is evaluated putting emphasis on the flexibility provided at the network interface level, showing outstanding speedups for a wide set of traffic patterns. At the architecture level, the potential impact of the BoWNoC paradigm on the design of manycore chips is not only qualitatively discussed in general, but also quantitatively assessed in a particular architecture for fast synchronization. Results demonstrate that the impact of BoWNoC can go beyond simply improving the network performance, thereby representing a possible game changer in the manycore era.Avenços en el disseny de multiprocessadors han portat a una àmplia adopció dels Chip Multiprocessors (CMPs), que basen el seu potencial en la operació coordinada de múltiples nuclis de procés. Generacions successives han anat integrant més nuclis en la recerca d'alt rendiment amb un cost raonable. Per a que aquesta tendència continuï, però, cal resoldre importants problemes d'escalabilitat a diferents capes de disseny. Escalar la xarxa d'interconnexió és un gran repte en ell mateix, ja que les noves propostes de Networks-on-Chip (NoC) han de servir un tràfic eminentment variable i heterogeni dels processadors amb molts nuclis. Són necessàries solucions ràpides i flexibles per evitar que les comunicacions dins del xip es converteixin en el pròxim coll d'ampolla de rendiment, situació que limitaria en gran mesura l'espai de disseny a nivell d'arquitectura i portaria a l'ús d'arquitectures i models de programació lents, ineficients o poc programables. L'aparició de noves tecnologies d'interconnexió ha possibilitat la creació de NoCs més flexibles i escalables. En particular, la comunicació intra-xip sense fils ha despertat un interès considerable en virtut de les seva baixa latència, simplicitat, i bon rendiment amb tràfic broadcast. La majoria de les Wireless NoC (WNoC) proposades fins ara s'han centrat en aprofitar l'avantatge en termes de latència d'aquest nou paradigma creant múltiples canals sense fils per interconnectar nuclis allunyats entre sí. Aquesta estratègia és efectiva per complementar a NoCs clàssiques en escales mitjanes, però és probable que altres tecnologies com la nanofotònica puguin jugar millor aquest paper a escales més grans. Aquesta tesi presenta el concepte de Broadcast-Oriented WNoC (BoWNoC), un nou enfoc que intenta rendibilitzar al màxim la inherent simplicitat, flexibilitat, i capacitats broadcast de la tecnologia sense fils integrant una antena i transmissor/receptor per cada nucli del processador. Aquest paradigma forma part d'una visió més àmplia on un BoWNoC serviria tràfic broadcast i urgent, mentre que una xarxa convencional serviria fluxos de dades més pesats. En virtut de la escalabilitat i del seu suport broadcast, BoWNoC podria convertir-se en un element clau en una gran varietat d'arquitectures i algoritmes poc convencionals que milloressin considerablement el rendiment, l'eficiència, l'escalabilitat i la programabilitat de processadors amb molts nuclis. El present treball té com a objectius no només estudiar els aspectes fonamentals del paradigma BoWNoC, sinó també demostrar la seva viabilitat des dels punts de vista de la implementació, i del disseny de xarxa i arquitectura. Una exploració a la capa física valida la viabilitat de l'enfoc usant tecnologies longituds d'ona milimètriques en un futur proper, i suggereix l'ús d'antenes de grafè a la banda dels terahertz ja a més llarg termini. A capa d'enllaç, la tesi aporta una anàlisi del context de l'aplicació que és, més tard, utilitzada per al disseny d'un protocol d'accés al medi que permet servir tràfic broadcast a baixa latència i de forma fiable. A capa de xarxa, la nostra visió híbrida és avaluada posant èmfasi en la flexibilitat que aporta el fet de prendre les decisions a nivell de la interfície de xarxa, mostrant grans millores de rendiment per una àmplia selecció de patrons de tràfic. A nivell d'arquitectura, l'impacte que el concepte de BoWNoC pot tenir sobre el disseny de processadors amb molts nuclis no només és debatut de forma qualitativa i genèrica, sinó també avaluat quantitativament per una arquitectura concreta enfocada a la sincronització. Els resultats demostren que l'impacte de BoWNoC pot anar més enllà d'una millora en termes de rendiment de xarxa; representant, possiblement, un canvi radical a l'era dels molts nuclisAward-winningPostprint (published version