The demand for streaming high-quality video increases each year and the energy used by consumers is estimated to increase by 23% from 2020 to 2030. The largest contributor to this is increased data transmission. To minimise data transmission, a video encoding method called per-shot encoding can be used, which splits and processes a video into smaller segments called shots. By utilising this method, the bitrate for a video can be reduced without compromising quality. This leads to less data that needs to be transmitted, which reduces energy consumption. In this project, a website that interfaces with a per-shot encoder is implemented. To evaluate the per-shot encoder, both visual quality and bitrate are quantitatively measured. From evaluation, the bitrate is reduced by up to 2.5% for a selection of videos, without compromising the viewing experience. This is a substantial decrease compared to alternative methods. / Efterfrågan av högkvalitativ videoströmning ökar varje år och konsumenters energianvändning uppskattas att ha ökat med 23% år 2030 jämfört med år 2020. Den största orsaken till detta är ökad dataöverföring. För att minska mängden data som behöver skickas kan per-shot-kodning användas, vilket är en videokodningsmetod som delar upp och bearbetar en video i ett flertal mindre delar som kallas shots. Bithastigheten för en video kan minskas med hjälp av per-shot-kodning utan att påverka kvaliteten. Detta leder till att mindre data behöver skickas, vilket innebär minskad energiförbrukning. I detta projekt har en per-shot-kodare tillsammans med en hemsida utvecklats. För att utvärdera per-shot-kodaren kommer skillnad i kvalitet och bithastighet att mätas kvantitativt. Utvärderingen har visat att per-shot-kodaren kan minska bithastigheten med upp till 2.5% för ett urval av videor, utan att påverka tittarupplevelsen. Detta är en avsevärd minskning jämfört med alternativa metoder.

Denna rapport beskriver utvecklingen av en referensdesign för en WiFi-modul från före- taget H&D Wireless. Referensdesignen skulle vara en kamera som kan skicka videodata trådlöst via den nyss nämnda WiFi-modulen. Projektet genomfördes under våren 2015 på företaget som examensarbete för Högskoleingenjörsprogrammet i elektronik och da- torteknik på KTH. Projektet delades upp i tre olika faser: en förstudiefas, en genomförbarhetsfas och en avslutande fas. I förstudiefasen gjordes en litteraturstudie som behandlade vanliga funktioner hos ex- isterande nätverkskameror, videokodningstekniker samt en något djupare studie av olika typer av bildsensorer. Förstudiefasen fortsatte med en analys av olika hårdvarulösningar som skulle kunna användas i projektet. I slutet av fasen valdes den hårdvara som skulle användas i projek- tet. Genomförbarhetsfasen gick ut på att ta reda på om den valda lösningen gick att ge- nomföra. I denna fas skedde huvudsakligen mjukvaruutveckling, under vilken testdriven utveckling tillämpades. En videobuffert samt en HTTP-server för videoströmning togs fram i denna fas. I den avslutande fasen färdigställdes projektrapporten och mjukvaruutvecklingen av- slutades. Mjukvaruutvecklingen för den valda videokodaren sköts upp på grund av att den levererades sent i projektet. I projektet användes en Scruminspirerad projektmetod. Projektmetoden upplevdes fungera bra på grund av metodens flexibilitet och påtvingande av tydliga uppgifter. Vid projektets slut kunde inte den trådlösa kameran färdigställas på grund av problem i kommunikationen med videokodaren. Om videokodaren hade kommit tidigare hade detta problem troligtvis hunnit åtgärdas innan projektets slut, men det är osäkert om implementationen hade hunnit färdigställas ändå på grund av den korta tid som fanns tillgänglig. Trots att projektet inte hann färdigställas helt har det gett många nyttiga lärdomar för framtiden. / company H&D Wireless. The reference design would be a wireless camera that can send video data wirelessly using the aforementioned WiFi-module. The project was carried out at the company during spring 2015 as a thesis project for the Degree Program in Electronics and Computer Engineering at KTH. The project was divided into three stages: a pilot study stage, a feasibility stage and a concluding stage. A literature study was performed during the pilot study stage, which described common functions in existing network cameras, techniques for video encoding and a slightly deeper study of different types of image sensors. The pilot study stage continued with an analysis of different hardware solutions which could be used in the project. The hardware solution which would be used in the project was chosen at the end of the pilot study stage. The purpose of the feasibility stage was to find out whether the chosen hardware solution would be possible to implement. This stage consisted mainly of software de- velopment, during which test driven development was practiced. A video buffer and a HTTP-server for video streaming was developed in this stage of the project. The project report was finished and the software development was wrapped up during the concluding stage. The development of the software for the chosen video encoder was delayed until the concluding stage because of its late delivery. A Scrum inspired project method was used for this project. The project method was perceived to work well in the project because of its flexibility and demand of clear tasks. The wireless camera could was not finished at the end of the project, because of problems in the communication with the video encoder. The problem could probably have been resolved before the end of the project if the video encoder had arrived earlier. It is not sure if the implementation had been possible to complete anyways because of lack of time. Although the project was not completely finished a lot of valuable knowledge was obtained for future work.

Video and body cameras are increasingly used by operational personnel, such as first responders, to improve situational awareness and safety of operations. However, to attain the full potential of video applications in this domain, operators need support to find the relevant information in the multiple video streams sent from the accident site. Needed are flexible applications that can handle multiple video streams and augment relevant parts of the video to support the operator. In this thesis, we present a video application, with virtual object augmentation and overlay functionality. The system handles a set of video streams and augments them using Unreal Engine and Gstreamer. Current modern software frameworks for video streaming and augmentation were examined as part of the development.  The performance of the application was evaluated using a simulated set of video streams and augmentation requests. Frames per second were measured to ensure a reliable and functional application. The study suggests that Unreal Engine, together with Gstreamer, is a suitable framework combination for the development of this application. Unreal Engine provides nDisplay, which is a powerful feature for multi-display setups. It supports synchronized presentation on displays, even in a cluster of multiple computers, with easy setup in a nDisplay editor. Furthermore, extending Unreal using C++ facilitates the integration with Gstreamer that enables integration with other applications with its native C++ support and external APIs for accessing media data. The performance measurements of the final application show adequate performance with respect to the defined use cases.

Users are shifting from traditional TV to video streaming platforms because of the flexibility of using these media. However, most studies on accessibility in media streaming platforms explore physical impairments. Despite ADHD and dyslexia affecting around 5 and 10 percent of the population, studies combining the experience in streaming services and this neurodiverse group are still limited. This study aims to understand how people with ADHD and dyslexia experience video streaming platforms. The investigation involved recruiting people from this neurodiverse population who consume streaming and facilitate sessions with semi-structured interviews and co-design. The results show that the participants did not always show empowerment to express their needs. The study suggests an explanation of the topics that will be covered during the sessions to prepare the participant for the co-design. By doing so, the participants can reflect on their experiences beforehand. Similarly, sending them a summary of how the design methodology works might help participants understand the importance of the process, giving them more empowerment before the session starts. These suggestions can support future studies involving this neurodiverse group to be more inclusive. / Mediakonsumenter flyttar från traditionell TV till streamingplattformar eftersom de är mer flexibla. De flesta studierna om tillgänglighet på streamingplattformar handlar däremot enbart om fysiska funktionsnedsättningar. Trots att ungefär 5 till 10 procent av befolkningen antingen har ADHD eller dyslexi är de få studier som tar upp neurodiversitet i samband med streamingtjänster. Den här studien försöker förstå hur personer med ADHD eller dyslexi upplever videostreamingplattformar. Undersökningen gick ut på att personer från den neurodiversa gruppen som använde streamingplattformar fick delta i semi-strukturerade intervjuer och co-design-sessioner. Resultaten visar att deltagarna ibland inte kände att de hade möjligheten att säga vad de tyckte. Den här studien föreslår att de ämnen som ska behandlas förklaras på förhand så deltagarna kan förbereda sig inför sessionen. Deltagarna kan på så sätt reflektera över sina egna erfarenheter på förhand. Att skicka en sammanfattning av hur designmetodik fungerar kan också hjälpa deltagarna förstå vikten av designprocessen, vilket stärker dem innan sessionen börjar. Den här förslagen är några sätt att öka gruppens makt i design-sessioner som möjliggör att framtida studier kan bli mer inkluderande.

Search on video streaming services is significantly different from web search engines and traditional information retrieval systems. Although an internal site search function’s primary purpose is similar to a web search engine’s, the user’s needs differ, which calls for a different design approach regarding the search result. Many previous researchers have investigated the algorithms behind search functions. However, there is a lack of studies related to the user experience of a search's user interface within the video streaming industry. This study investigates how different presentations of search results affect the users to complete a search on web-based video streaming services. The study was done in collaboration with SVT, examining their video streaming service SVT Play. The research aimed to answer three research questions based on the official usability standard ISO 9241–11. A prototype was designed from a state-of-the-art analysis and the findings from three focus group interviews. An A/B test was conducted on the developed prototype, comparing it against the original search function live on SVT Play, including 46 860 test users. A complementary user test with 10 participants was done in addition to the A/B test. The findings from the A/B test did not show any significant difference between the prototypes. It highlighted that users’ search goals are strong enough not to let the layout and design affect their choice, hence the overall click-through rates. However, the user test showed that the new prototype was, in general, easier to use. It also showed that the different prototypes suited different search goals. The participants expressed a wish to have a solution that combines the design elements from the two prototypes. / Sökfunktionen på videostreamingtjänster skiljer sig från webbsökmotorer och traditionella informationssökningssystem. Även om det primära syftet av en sökfunktion på en intern webbplats liknar webbsökmotorns, så skiljer sig användarens behov vilket därav kräver en annan designmetod. Många tidigare forskare har undersökt algoritmerna bakom sökfunktioner. Dock saknas studier relaterade till användarupplevelsen av sökets gränssnitt inom videostreaming industrin. Denna studie undersöker hur olika presentationer av sökresultatet påverkar användarna för att slutföra en sökning på en webbaserad videostreamingtjänst. Studien gjordes i samarbete med SVT och därav utgick undersökningen från deras videostreamingtjänst SVT Play. Uppsatsen syftade till att svara på tre forskningsfrågor utformade efter den officiella användbarhetsstandarden ISO 9241–11. En prototyp togs fram baserad på en toppmodern analys och resultat från fokusgruppsintervjuer. Ett A/B test med 46 860 testanvändare utfördes med syfte att jämföra den framtagna prototypen med den ursprungliga sökfunktionen på SVT Play. Ett kompletterande användartest med tio deltagare gjordes utöver A/B testet. Resultaten från A/B testet visade ingen signifikant skillnad mellan prototyperna. Det framhöll att användarnas sökmål är tillräckligt starka för att layout och design ska påverka deras val och därav den totala klickfrekvensen. Användartestet visade att den nya prototypen generellt var lättare att använda. Studien visade också att de olika prototyperna passade olika sökmål. Deltagarna uttryckte en önskan om en lösning som kombinerar designelement från de två olika prototyperna.

A drastic increase in traffic of mobile broadband is seen in the past few years, which is further accelerated by the increase in usage of smart phones and its applications. The availability of good smart phones and better data connectivity are encouraging mobile users to use video services. This huge increase in usage will pose a lot of challenges to the wireless networks. The wireless network has to become content aware in order to offer enhanced quality of video service through efficient utilization of the wireless spectrum. This thesis focuses on improving the Quality of Experience (QoE) for video transmission over Long Term Evolution (LTE) networks by imparting the content awareness to the system and providing unequal error protection for critical video packets. Two different schemes for the improvement of video quality delivery over LTE networks are presented in this thesis. Using content awareness, the retransmission count of Hybrid Automatic Repeat reQuest (HARQ) are changed dynamically such that the most important video frame gets more number of retransmission attempts, which increases its success for delivery in-turn increasing the received video quality. Since Radio Link Control (RLC) is the link layer for radio interface, the second approach focuses on optimizing this layer for efficient video transmission. As part of this scheme, a new operation mode called Hybrid Mode (HM) for RLC is defined. This mode performs retransmission only for the critical video frames, leaving other frames to unacknowledged transmission. The simulation results of both proposed schemes provide significant improvement in achieving good video quality without affecting the system performance.

Šiame darbe buvo ištirtas keleto pasirinktų objekto vaizde sekimo metodų pritaikomumas relaus laiko vaizdo transliavimo sistemose. Išsiaiškinta, kad standartinis blokelių sutapdinimo algoritmas, nors yra pats paprasčiausias iš tirtųjų, yra netinkamas naudoti tokiose sistemose dėl ilgai užtrunkančių skaičiavimų, kurie sukuria papildomą vaizdo vėlinimą. Fazinės koreliacijos metodo taikymo taip pat buvo atsisakyta, nes jo randami vaizdo poslinkio vektoriai yra pernelyg atsitiktiniai. Tiriant būdingųjų taškų paieška ir sutapdinimu grįstus algoritmus buvo išsiaiškinta, kad HARRIS randa daugiausiai taškų iš visų, FAST algoritmas veikia greičiausiai, nors randamų taškų skaičius ir tikslumas yra žymiai mažesnis, o SURF ir MSER algoritmai puikiai balansuoja tarp randamų taškų skaičiaus, jų tikslumo ir skaičiavimų vykdymo greičio. Padarėme išvadas, kad visi tirti būdingųjų taškų sutapdinimu ir paieška pagrįsti metodai, priklausomai nuo uždavinio pobūdžio, gali būti taikomi realaus laiko vaizdo transliacijos sistemos objektams vaizde sekti. / In this thesis we've investigated methods used in object tracking in video sequences, that could be applied in systems of real-time video streaming. We've found out that a standard block matching method, despite being the most simplistic one out of all methods investigated, is also the most time consuming and cannot be applied in real-time systems. Phase correlation method is much faster than block matching, but motion vectors calculated with this algorithm are too random and it would be impractical to use it in real-time object tracking. While investigating feature detection and matching methods we've concluded that HARRIS algorithm finds more feature points than others, FAST algorithm is the fastest, but not very accurate, SURF and MSER algorithms retains the balance between the calculation speed and accuracy of finding feature points. Hence all these algorithms could be applied in real-time video streaming systems to track objects, depending on the contents of the video sequence and the complexity of the task.

Le but de cette thèse est de proposer des mécanismes efficaces pour l'ordonnancement des chunks et l'allocation de la bande passante dans le contexte de la transmission vidéo sur les réseaux P2P,afin d'offrir une meilleure qualité de service pour l'utilisateur final. Dans un premier temps nousavons proposé un mécanisme d'ordonnancement des chunks pour la transmission de vidéomulticouche dans les réseaux P2P. Le mécanisme proposé est basé sur une nouvelle technique quipermet de sélectionner les chunks adéquats et les demander des pairs les plus appropriés. Ensuitenous avons proposé un mécanisme d'allocation de la bande passante, toujours dans le cadre detransmission de vidéo multicouche dans les réseaux P2P. Le pair émetteur organise une enchère pour«vendre » sa bande passante. L'allocation tient en considération la priorité des pairs et l'importancedes couches demandées. Finalement nous avons proposé un mécanisme d'adaptation lisse « smooth» d'une vidéo multicouche transportée sur un réseau P2P.Après une introduction, nous présentons dans le chapitre 2 les motivations du travail le but du travailet les problèmes recherche qui demeurent. Dans ce chapitre nous présentons les composants dessystèmes P2P et tout particulièrement la distribution et l'adaptation de contenus. Dans ce cadre,nous proposons une classification des applications de streaming vidéo P2P ainsi que des mécanismesd'allocation de bande passante et d'ordonnancement pour le streaming pair-à-pair. Nous nousintéressons également aux techniques d'adaptation de la qualité en se focalisant plusparticulièrement sur la norme SVC (Scalable Video Coding).Le chapitre 3 propose des mécanismes de priorisation pour la planification de streaming P2P multicouches.Nous proposons une heuristique pour résoudre un problème général d'affectationgénéralisé (Generalized Assignment Problem – GAP). La solution présentée est ensuite adaptée aucas du streaming non multicouches. Les résultats issus des simulations montrent que les solutionsproposées donnent de meilleurs résultats que les solutions traditionnelles.Le chapitre 4 décrit un mécanisme d'allocation dynamique de la bande passante pour les réseaux destreaming P2P multicouches qui se base sur l'allocation d'une bande passante aux pairs tout enassurant un minimum de qualité de service à l'ensemble des pairs. Les bonnes performances desmécanismes proposés, qui sont détaillées à travers l'étude du ratio concernant l'utilisation de labande passante ainsi que du niveau de satisfaction des pairs, montrent que ces derniers permettentd'obtenir une utilisation optimale de la bande passante.Le chapitre 5 porte sur le lissage du streaming multicouches dans les réseaux P2P en se basant sur lesmétriques liées à la variation de la fréquence et de l'amplitude. Les mécanismes proposés ont étéimplémentés dans un banc d'essai réel et l'évaluation des performances montrent l'efficacité desmécanismes pour le lissage du streaming.Dans le chapitre 6 (conclusion and perspectives), nous résumons les contributions proposées danscette thèse ainsi qu’une ouverture sur les travaux futures / Recently we witnessed an increasing demand for scalable deployment of real-time multimediastreaming applications over Internet. In this context, Peer-to-Peer (P2P) networks are playing asignificant role for supporting large-scale and robust distribution of multimedia content to end-users.However, due to peers’ dynamicity, heterogeneity of terminals and access networks, the deploymentof real-time video streaming applications over P2P networks arises lot of challenges. Indeed, animportant issue in P2P overlays is the capacity to self-organize in the face of the dynamic behavior ofpeers in order to ensure content availability and continuity. In addition, the heterogeneity in networks,terminals, and P2P characteristics make the situation more challenging. In this context, layered videostreaming in P2P networks has drawn great interest to overcome these challenges, since it can notonly accommodate large numbers of users, but also handle heterogeneity of peers. However, there isstill a lack of comprehensive studies on video data blocks (chunks) scheduling and bandwidthallocation for the smooth playout in layered streaming over P2P networks.The aim of this thesis is to analyze these concerns and to propose an efficient real-time chunksscheduling and bandwidth allocation mechanisms for QoS provisioning of layered streamingapplications over P2P networks. Our contributions in this thesis are threefold. First, we propose ascheduling mechanism for layered P2P streaming. The proposed mechanism relies on a novelscheduling algorithm that enables each peer to select appropriate stream layers, along withappropriate peers to provide them. The presented mechanism makes efficient use of networkresources and provides high system throughput. Second, we propose a bandwidth allocation modelfor P2 layered streaming systems based on auction mechanisms to optimize the allocation of senderpeers’ uploads bandwidth. The upstream peers organize auctions to “sell” theirs items (links’bandwidth) according to bids submitted by the downstream peers taking into consideration the peerspriorities and the requested layers importance. The ultimate goal is to satisfy the quality levelrequirement for each peer, while reducing the overall streaming cost. Finally, we present a smoothingmechanism for layered streaming in P2P networks. The mechanism aims to reduce the number oflayer changes under varying network conditions, and ensure a smooth playout for the end-user.

Esta Tese propõe duas métricas objetivas para avaliar a percepção de qualidade de vídeos sujeitos a degradações de transmissão em uma rede de pacotes. A primeira métrica usa apenas o vídeo degradado, enquanto que a segunda usa os vídeos de referência e degradado. Esta última é uma métrica de referência completa (FR - Full Reference) chamada de QCM (Quadratic Combinational Metric) e a primeira é uma métrica sem referência (NR - No Reference) chamada de VQOM (Viewing Quality Objective Metric). Em particular, o procedimento de projeto é aplicado à degradação de variação de atraso de pacotes (PDV - Packet Delay Variation). A métrica NR é descrita por uma spline cúbica composta por dois polinômios cúbicos que se encontram suavemente num ponto chamado de nó. Para o projeto de ambas métricas, colhem-se opiniões de observadores a respeito das sequências de vídeo degradadas que compõem o conjunto. A função objetiva inclui o erro quadrático total entre as opiniões e suas estimativas paramétricas, ainda consideradas como expressões algébricas. Acrescentam-se à função objetiva três condições de igualdades de derivadas tomadas no nó, cuja posição é especificada dentro de uma grade fina de pontos entre o valor mínimo e o valor máximo do fator de degradação. Essas condições são afetadas por multiplicadores de Lagrange e adicionadas à função objetiva, obtendo-se o lagrangiano, que é minimizado pela determinação dos coeficientes subótimos dos polinômios em função de cada valor do nó na grade. Finalmente escolhe-se o valor do nó que produz o erro quadrático mínimo, determinando assim os valores finais para dos coeficientes do polinômio. Por outro lado, a métrica FR é uma combinação não-linear de duas métricas populares, a PSNR (Peak Signal-to-Noise Ratio) e a SSIM (Structural Similarity Index). Um polinômio completo de segundo grau de duas variáveis é usado para realizar a combinação, porque é sensível a ambas métricas constituintes, evitando o sobreajuste em decorrência do baixo grau. Na fase de treinamento, o conjunto de valores dos coeficientes do polinômio é determinado através da minimização do erro quadrático médio para as opiniões sobre a base de dados de treino. Ambas métricas, a VQOM e a QCM, são treinadas e validadas usando uma base de dados, e testadas com outra independente. Os resultados de teste são comparados com métricas NR e FR recentes através de coeficientes de correlação, obtendo-se resultados favoráveis para as métricas propostas. / This dissertation proposes two objective metrics for estimating human perception of quality for video subject to transmission degradation over packet networks. The first metric just uses traffic data while the second one uses both the degraded and the reference video sequences. That is, the latter is a full reference (FR) metric called Quadratic Combinational Metric (QCM) and the former one is a no reference (NR) metric called Viewing Quality Objective Metric (VQOM). In particular, the design procedure is applied to packet delay variation (PDV) impairments, whose compensation or control is very important to maintain quality. The NR metric is described by a cubic spline composed of two cubic polynomials that meet smoothly at a point called a knot. As the first step in the design of either metric, the spectators score a training set of degraded video sequences. The objective function for designing the NR metric includes the total square error between the scores and their parametric estimates, still regarded as algebraic expressions. In addition, the objective function is augmented by the addition of three equality constraints for the derivatives at the knot, whose position is specified within a fine grid of points between the minimum value and the maximum value of the degradation factor. These constraints are affected by Lagrange multipliers and added to the objective function to obtain the Lagrangian, which is minimized by the suboptimal polynomial coefficients determined as a function of each knot in the grid. Finally, the knot value is selected that yields the minimum square error. By means of the selected knot value, the final values of the polynomial coefficients are determined. On the other hand, the FR metric is a nonlinear combination of two popular metrics, namely, the Peak Signal-to-Noise Ratio (PSNR) and the Structural Similarity Index (SSIM). A complete second-degree two-variable polynomial is used for the combination since it is sensitive to both constituent metrics while avoiding overfitting. In the training phase, the set of values for the coefficients of this polynomial is determined by minimizing the mean square error to the opinions over the training database. Both metrics, the VQOM and the QCM, are trained and validated using one database and tested with a different one. The test results are compared with recent NR and FR metrics by means of correlation coefficients, obtaining favorable results for the proposed metrics.

Le routage par clé et par contenu sont des systèmes de routage ou la destination d'un message suit un parcours entre les nœuds du réseau qui dépend seulement du contenu du message même. On peut les trouver utilisés soit dans des systèmes pair-à-pair connus comme Réseaux Overlay Structurés (Structured Overlay Networks, SON), soit dans les architecture internet de nouvelle génération, les Réseaux Centrés sur les Contenus (Content-Centric Networks, CCN). Le but de cette thèse est double. D'un côté, on explore le sujet de l'interconnexion et de la coopération des réseaux d'overlay, et on propose une architecture capable de permettre à plusieurs réseaux d'overlay hétérogènes, avec différentes topologies et différents mécanismes de routage, d'interagir, grâce à une infrastructure basée sur des nœuds passerelles. On montre, par des moyennes de simulation et déploiement dans un réseaux réel, que la solution est scalable et permet un routage quasi-exhaustif avec un nombre relativement bas des nœuds passerelle bien connectés. De plus, on présente deux exemples d'applications qui pourront bénéficier de cette architecture. Dans une deuxième partie, on rentre plutôt dans les possibilités offertes par le routage basé sur les contenus hors sa "zone de confort": d'abord, on analyse les améliorations qu'un réseau d'overlay structuré peut porter à un système de diffusion vidéo pair-à-pair, en termes de qualité du vidéo et de perte des paquets pendant la transmission. Après, on examine un système entièrement centré sur le routage basé sur les contenus, en développant une solution de diffusion vidéo en temps réel dans un réseau CCN. / Key-based and content-based routing are a class of routing techniques where the destination and routing path for a message depends solely on the content of the message itself. This kind of routing has been implemented in certain peer-to-peer systems, known as Structured Overlay Networks (SON), or in the Next Generation Internet architectures, under the name of Content-Centric Networks (CCN). The scope of this thesis is twofold: on the one side, we explore the topic of the interconnection and cooperation of different structured overlays, and propose architecture capable of allowing several heterogeneous overlay networks, with different topologies and different routing schemes, to interact, thanks to a lightweight infrastructure consisting of co-located nodes. Through the use of simulations and real-world deployment, we show how this solution is scalable and how it facilitates quasi-exhaustive routing, with even a relatively low number of well-connected co-located nodes. To address the problem of scaling network design to millions of nodes, we propose a mathematical model capable of deriving basic performance figures for an interconnected system. Furthermore, we present two application examples that could greatly benefit from such architecture. On the other side, we investigate a little further into the capabilities of content-based routing outside of its "comfort zone": first, we analyze the improvement that a SON could bring to a peer-to-peer real-time video streaming system (P2P-TV), in terms of chunk loss and Quality of Experience. Then, we move the approach to a fully content-based domain, implementing the P2P-TV solution on top of Content-Centric Networks.