The Design of a System Architecture for Mobile Multimedia Computers

This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies

Adaptive Voice Applications over Delay Tolerant Networks

Internet is predominantly based on best effort packet transmission. Performance of applications over internet suffers due to disconnections, delays, losses and dynamic nature of elements in the network. Voice communications, such as Voice over Internet Protocols (VoIP), over mobile networks has to deal with technical barriers such as delays and temporary disconnections. Delay tolerant networks provides communication based on asynchronous messaging that deals with delays and disconnections; which provides a mechanism to deliver the messages irrespective of instantaneous end-to-end path connectivity. In the thesis, delay tolerant adaptive media is proposed to allow DTN-based communication as a fall-back if real time end-to-end voice communication fails. We designed a system which adapts to delays and losses by switching between RTP/UDP and RTP/DTN-based voice packets transmission. The real time communication works fine as long as continuous end-to-end path exists. The continuous path might not exist when there are changes in the network topology of mobile users. So in the case of non-availability of end-to-end path, we swiftly adapt to RTP/DTN-based voice with variable length messaging mechanism. To assess the call quality in different modes of operation, we used R values of E model specified by ITU-T. The results show that the proposed delay tolerant adaptive media for adaptive voice over delay tolerant networks achieves better utility for the users when end-to-end connectivity is not available or when delays are higher

Overview of UMTS network evolution through radio and transmission feature validation

This project is based on several UMTS network feature validation with the aim to provide an end-to-end in-depth knowledge overview gained in parallel in the areas of radio network mobility processes (cell camping and inter-system handover), Quality of Service improvement for HSPA data users and transport network evolution towards the All-IP era.Hardware and software validation is a key step in the relationship between the mobile network operator and the vendor. Through this verification process, while executing that functionality or testing a specific hardware, the difference between the actual result and expected result can be better understood and, in turn, this in-depth knowledge acquisition is translated into a tailored usage of the product in the operator’s live network. As a result, validation helps in building a better product as per the customer’s requirement and helps satisfying their needs, which positively impacts in the future evolution of the vendor product roadmap implementation process for a specific customer. This project is based on several Universal Mobile Telecommunication Services (UMTS) network feature validation with the aim to provide an end-to-end in-depth knowledge overview gained in parallel in the areas of radio network mobility processes (cell camping and inter-system handover), Quality of Service improvement for High Speed Downlink Packet Access (HSPA) data users and transport network evolution towards the All-IP era.Las campañas de validación hardware y software son un paso clave en las relaciones comerciales establecidas entre un operador de telecomunicaciones y su proveedor de equipos de red. Durante los procesos de certificación, mientras se ejecuta una funcionalidad software o se valida un determinado hardware, se obtiene un conocimiento profundo de la diferencia entre el resultado obtenido y el esperado, repercutiendo directamente en un uso a medida de dicha funcionalidad o hardware en la propia red del cliente. Como consecuencia de lo anterior, podemos aseverar que los procesos de validación permiten en gran medida al proveedor adaptarse mejor a los requerimientos del cliente, ayudando a satisfacer realmente sus necesidades. Esto implica directamente un impacto positivo en la futura evolución del portfolio que el fabricante ofrece a un determinado cliente. Este proyecto está basado en la validación de diferentes funcionalidades de red UMTS, cuyo objetivo es proporcionar un conocimiento global de distintos aspectos que conforman el funcionamiento de una red de telecomunicaciones 3G, como son los procesos de movilidad de acceso radio (acampado de red y handover inter-sistema), las mejoras en la calidad de servicio para usuarios de datos HSPA y la convergencia de la red de transporte hacia la era IP.Els processos de validació hardware i software són un punt clau en les relacions comercials establertes entre un operador de telecomunicaciones i el proveïdor d'equipament de la xarxa. En el transcurs dels processos de certificació, a la mateixa vegada que s'executa una funcionalitat software o es valida un determinat hardware, s'obtenen grans coneixements respecte la diferència entre el resultat obtingut i l'esperat, que són d'aplicació directa a l'hora d'establir un ús adpatat a la xarxa del client. En conseqüència, podem asseverar que les campanyes de validació permeten en gran mesura al proveïdor adaptar-se millor als requeriments del client, ajudant a satisfer realment les seves necessitats. Això implica directament un impacte positiu en la futura evol.lució del portfoli que el fabricant ofereix a un determinat client. Aquest projecte es basa en la presentació d'un procès de validació de diferents funcionalitats relacionades amb la xarxa UMTS, amb l'objectiu de proporcionar un coneixement global de la varietat d'aspectes que conformen el funcionament d'una xarxa de telecomunicacions 3G, com són els processos de mobilitat en accès radio (acampat de l'usuari i handover inter-sistema), millores en la qualitat de servei per a usuaris de dades HSPA i la convergència de la xarxa de transport cap a l'era IP

Flexible cross layer optimization for fixed and mobile broadband telecommunication networks and beyond

In der heutigen Zeit, in der das Internet im Allgemeinen und Telekommunikationsnetze im Speziellen kritische Infrastrukturen erreicht haben, entstehen hohe Anforderungen und neue Herausforderungen an den Datentransport in Hinsicht auf Effizienz und Flexibilität. Heutige Telekommunikationsnetze sind jedoch rigide und statisch konzipiert, was nur ein geringes Maß an Flexibilität und Anpassungsfähigkeit der Netze ermöglicht und darüber hinaus nur im begrenzten Maße die Wichtigkeit von Datenflüssen im wiederspiegelt. Diverse Lösungsansätze zum kompletten Neuentwurf als auch zum evolutionären Konzept des Internet wurden ausgearbeitet und spezifiziert, um diese neuartigen Anforderungen und Herausforderungen adäquat zu adressieren. Einer dieser Ansätze ist das Cross Layer Optimierungs-Paradigma, welches eine bisher nicht mögliche direkte Kommunikation zwischen verteilten Funktionalitäten unterschiedlichen Typs ermöglicht, um ein höheres Maß an Dienstgüte zu erlangen. Ein wesentlicher Indikator, welcher die Relevanz dieses Ansatzes unterstreicht, zeichnet sich durch die Programmierbarkeit von Netzwerkfunktionalitäten aus, welche sich aus der Evolution von heutigen hin zu zukünftigen Netzen erkennen lässt. Dieses Konzept wird als ein vielversprechender Lösungsansatz für Kontrollmechanismen von Diensten in zukünftigen Kernnetzwerken erachtet. Dennoch existiert zur Zeit der Entstehung dieser Doktorarbeit kein Ansatz zur Cross Layer Optimierung in Festnetz-und Mobilfunknetze, welcher der geforderten Effizienz und Flexibilität gerecht wird. Die übergeordnete Zielsetzung dieser Arbeit adressiert die Konzeptionierung, Entwicklung und Evaluierung eines Cross Layer Optimierungsansatzes für Telekommunikationsnetze. Einen wesentlichen Schwerpunkt dieser Arbeit stellt die Definition einer theoretischen Konzeptionierung und deren praktischer Realisierung eines Systems zur Cross Layer Optimierung für Telekommunikationsnetze dar. Die durch diese Doktorarbeit analysierten wissenschaftlichen Fragestellungen betreffen u.a. die Anwendbarkeit von Cross Layer Optimierungsansätzen auf Telekommunikationsnetzwerke; die Betrachtung neuartiger Anforderungen; existierende Konzepte, Ansätze und Lösungen; die Abdeckung neuer Funktionalitäten durch bereits existierende Lösungen; und letztendlich den erkennbaren Mehrwert des neu vorgeschlagenen Konzepts gegenüber den bestehenden Lösungen. Die wissenschaftlichen Beiträge dieser Doktorarbeit lassen sich grob durch vier Säulen skizzieren: Erstens werden der Stand der Wissenschaft und Technik analysiert und bewertet, Anforderungen erhoben und eine Lückenanalyse vorgenommen. Zweitens werden Herausforderungen, Möglichkeiten, Limitierungen und Konzeptionierungsaspekte eines Modells zur Cross Layer Optimierung analysiert und evaluiert. Drittens wird ein konzeptionelles Modell - Generic Adaptive Resource Control (GARC) - spezifiziert, als Prototyp realisiert und ausgiebig validiert. Viertens werden theoretische und praktische Beiträge dieser Doktorarbeit vertiefend analysiert und bewertet.As the telecommunication world moves towards a data-only network environment, signaling, voice and other data are similarly transported as Internet Protocol packets. New requirements, challenges and opportunities are bound to this transition and influence telecommunication architectures accordingly. In this time in which the Internet in general, and telecommunication networks in particular, have entered critical infrastructures and systems, it is of high importance to guarantee efficient and flexible data transport. A certain level of Quality-of-Service (QoS) for critical services is crucial even during overload situations in the access and core network, as these two are the bottlenecks in the network. However, the current telecommunication architecture is rigid and static, which offers very limited flexibility and adaptability. Several concepts on clean slate as well as evolutionary approaches have been proposed and defined in order to cope with these new challenges and requirements. One of these approaches is the Cross Layer Optimization paradigm. This concept omits the strict separation and isolation of the Application-, Control- and Network-Layers as it enables interaction and fosters Cross Layer Optimization among them. One indicator underlying this trend is the programmability of network functions, which emerges clearly during the telecommunication network evolution towards the Future Internet. The concept is regarded as one solution for service control in future mobile core networks. However, no standardized approach for Cross Layer signaling nor optimizations in between the individual layers have been standardized at the time this thesis was written. The main objective of this thesis is the design, implementation and evaluation of a Cross Layer Optimization concept on telecommunication networks. A major emphasis is given to the definition of a theoretical model and its practical realization through the implementation of a Cross Layer network resource optimization system for telecommunication systems. The key questions answered through this thesis are: in which way can the Cross Layer Optimization paradigm be applied on telecommunication networks; which new requirements arise; which of the required functionalities cannot be covered through existing solutions, what other conceptual approaches already exist and finally whether such a new concept is viable. The work presented in this thesis and its contributions can be summarized in four parts: First, a review of related work, a requirement analysis and a gap analysis were performed. Second, challenges, limitations, opportunities and design aspects for specifying an optimization model between application and network layer were formulated. Third, a conceptual model - Generic Adaptive Resource Control (GARC) - was specified and its prototypical implementation was realized. Fourth, the theoretical and practical thesis contributions was validated and evaluated

Control of real-time multimedia applications in best-effort networks

The increasing demand for real-time multimedia applications and the lack of quality of service (QoS) support in public best-effort or Internet Protocol (IP) networks has prompted many researchers to propose improvements on the QoS of such networks. This research aims to improve the QoS of real-time multimedia applications in public best-effort networks, without modifying the core network infrastructure or the existing codecs of the original media applications. A source buffering control is studied based on a fluid model developed for a single flow transported over a best-effort network while allowing for flow reversal. It is shown that this control is effective for QoS improvement only when there is sufficient flow reversal or packet reordering in the network. An alternate control strategy based on predictive multi-path switching is studied where only two paths are considered as alternate options. Initially, an emulation study is performed, exploring the impact of path loss rate and traffic delay signal frequency content on the proposed control. The study reveals that this control strategy provides the best QoS improvement when the average comprehensive loss rates of the two paths involved are between 5% and 15%, and when the delay signal frequency content is around 0.5 Hz. Linear and nonlinear predictors are developed using actual network data for use in predictive multi-path switching control. The control results show that predictive path switching is better than no path switching, yet no one predictor developed is best for all cases studied. A voting based control strategy is proposed to overcome this problem. The results show that the voting based control strategy results in better performance for all cases studied. An actual voice quality test is performed, proving that predictive path switching is better than no path switching. Despite the improvements obtained, predictive path switching control has some scalability problems and other shortcomings that require further investigation. If there are more paths available to choose from, the increasing overhead in probing traffic might become unacceptable. Further, if most of the VoIP flows on the Internet use this control strategy, then the conclusions of this research might be different, requiring modifications to the proposed approach. Further studies on these problems are needed

Quality of service support for multimedia applications in mobile ad hoc networks

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Design and Implementation of a Low-Cost Cloud-Powered Home Automation System

synergy of these technologies such as intelligent lighting, entertainment (audio and video), security, heating, ventilation and air conditioning in the home for the automation of control and monitoring activities within that home is typically known as Home Automation today. The Home global home automation market size was approximated to be about USD 45.8 billion in just 2017 and is projected to reach as high as USD 114 Billion at the tail of 2025 with a compound annual growth rate of 12.1% in this forecast period [1]. North America is projected to emerge as the leading region in the global landscape during the forecast period, but West African countries such as Nigeria, Ghana, Cameroon are generally seen to have a much lower adoption rate when it comes to emerging technologies like these. The low adoption rate is due in part to the high cost of implementing a home Automation solution coupled with the general economic state of these developing countries. The interest and investment of the tech industry within the countries also play a role in this context. This paper explores the design and implementation of a relatively less costly cloud-based home automation architecture built partly on open-source technology and widely available resources. The solution was realized using a raspberry pi as the field gateway and primary controller. Arduino Uno microcontroller were used as the secondary controller. The highly robust Microsoft Azure cloud was used, enabling the representation, testing, deploying, and managing applications and systems and services on the cloud and at the edge. In demonstrating the feasibility of the proposed system, three systems were integrated: intelligent lighting, basic access security and remote monitoring. These would be monitored and controlled by a simple mobile app whose communication with the field devices is made possible through the Microsoft Azure IoT solution