223 research outputs found

    A quality of experience approach in smartphone video selection framework for energy efficiency

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    Online video streaming is getting more common in the smartphone device nowadays. Since the Corona Virus (COVID-19) pandemic hit all human across the globe in 2020, the usage of online streaming among smartphone user are getting more vital. Nevertheless, video streaming can cause the smartphone energy to drain quickly without user to realize it. Also, saving energy alone is not the most significant issues especially if with the lack of attention on the user Quality of Experience (QoE). A smartphones energy management is crucial to overcome both of these issues. Thus, a QoE Mobile Video Selection (QMVS) framework is proposed. The QMVS framework will govern the tradeoff between energy efficiency and user QoE in the smartphone device. In QMVS, video streaming will be using Dynamic Video Attribute Pre-Scheduling (DVAP) algorithm to determine the energy efficiency in smartphone devices. This process manages the video attribute such as brightness, resolution, and frame rate by turning to Video Content Selection (VCS). DVAP is handling a set of rule in the Rule Post-Pruning (RPP) method to remove an unused node in list tree of VCS. Next, QoE subjective method is used to obtain the Mean Opinion Score (MOS) of users from a survey experiment on QoE. After both experiment results (MOS and energy) are established, the linear regression technique is used to find the relationship between energy consumption and user QoE (MOS). The last process is to analyze the relationship of VCS results by comparing the DVAP to other recent video streaming applications available. Summary of experimental results demonstrate the significant reduction of 10% to 20% energy consumption along with considerable acceptance of user QoE. The VCS outcomes are essential to help users and developer deciding which suitable video streaming format that can satisfy energy consumption and user QoE

    Teenustele orienteeritud ja tÔendite-teadlik mobiilne pilvearvutus

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    Arvutiteaduses on kaks kĂ”ige suuremat jĂ”udu: mobiili- ja pilvearvutus. Kui pilvetehnoloogia pakub kasutajale keerukate ĂŒlesannete lahendamiseks salvestus- ning arvutusplatvormi, siis nutitelefon vĂ”imaldab lihtsamate ĂŒlesannete lahendamist mistahes asukohas ja mistahes ajal. TĂ€psemalt on mobiilseadmetel vĂ”imalik pilve vĂ”imalusi Ă€ra kasutades energiat sÀÀsta ning jagu saada kasvavast jĂ”udluse ja ruumi vajadusest. Sellest tulenevalt on kĂ€esoleva töö peamiseks kĂŒsimuseks kuidas tuua pilveinfrastruktuur mobiilikasutajale lĂ€hemale? Antud töös uurisime kuidas mobiiltelefoni pilveteenust saab mobiilirakendustesse integreerida. Saime teada, et töö delegeerimine pilve eeldab mitmete pilve aspektide kaalumist ja integreerimist, nagu nĂ€iteks ressursimahukas töötlemine, asĂŒnkroonne suhtlus kliendiga, programmaatiline ressursside varustamine (Web APIs) ja pilvedevaheline kommunikatsioon. Nende puuduste ĂŒletamiseks lĂ”ime Mobiilse pilve vahevara Mobile Cloud Middleware (Mobile Cloud Middleware - MCM) raamistiku, mis kasutab deklaratiivset teenuste komponeerimist, et delegeerida töid mobiililt mitmetele pilvedele kasutades minimaalset andmeedastust. Teisest kĂŒljest on nĂ€idatud, et koodi teisaldamine on peamisi strateegiaid seadme energiatarbimise vĂ€hendamiseks ning jĂ”udluse suurendamiseks. Sellegipoolest on koodi teisaldamisel miinuseid, mis takistavad selle laialdast kasutuselevĂ”ttu. Selles töös uurime lisaks, mis takistab koodi mahalaadimise kasutuselevĂ”ttu ja pakume lahendusena vĂ€lja raamistiku EMCO, mis kogub seadmetelt infot koodi jooksutamise kohta erinevates kontekstides. Neid andmeid analĂŒĂŒsides teeb EMCO kindlaks, mis on sobivad tingimused koodi maha laadimiseks. VĂ”rreldes kogutud andmeid, suudab EMCO jĂ€reldada, millal tuleks mahalaadimine teostada. EMCO modelleerib kogutud andmeid jaotuse mÀÀra jĂ€rgi lokaalsete- ning pilvejuhtude korral. Neid jaotusi vĂ”rreldes tuletab EMCO tĂ€psed atribuudid, mille korral mobiilirakendus peaks koodi maha laadima. VĂ”rreldes EMCO-t teiste nĂŒĂŒdisaegsete mahalaadimisraamistikega, tĂ”useb EMCO efektiivsuse poolest esile. LĂ”puks uurisime kuidas arvutuste maha laadimist Ă€ra kasutada, et tĂ€iustada kasutaja kogemust pideval mobiilirakenduse kasutamisel. Meie peamiseks motivatsiooniks, et sellist adaptiivset tööde tĂ€itmise kiirendamist pakkuda, on tagada kasutuskvaliteet (QoE), mis muutub vastavalt kasutajale, aidates seelĂ€bi suurendada mobiilirakenduse eluiga.Mobile and cloud computing are two of the biggest forces in computer science. While the cloud provides to the user the ubiquitous computational and storage platform to process any complex tasks, the smartphone grants to the user the mobility features to process simple tasks, anytime and anywhere. Smartphones, driven by their need for processing power, storage space and energy saving are looking towards remote cloud infrastructure in order to solve these problems. As a result, the main research question of this work is how to bring the cloud infrastructure closer to the mobile user? In this thesis, we investigated how mobile cloud services can be integrated within the mobile apps. We found out that outsourcing a task to cloud requires to integrate and consider multiple aspects of the clouds, such as resource-intensive processing, asynchronous communication with the client, programmatically provisioning of resources (Web APIs) and cloud intercommunication. Hence, we proposed a Mobile Cloud Middleware (MCM) framework that uses declarative service composition to outsource tasks from the mobile to multiple clouds with minimal data transfer. On the other hand, it has been demonstrated that computational offloading is a key strategy to extend the battery life of the device and improves the performance of the mobile apps. We also investigated the issues that prevent the adoption of computational offloading, and proposed a framework, namely Evidence-aware Mobile Computational Offloading (EMCO), which uses a community of devices to capture all the possible context of code execution as evidence. By analyzing the evidence, EMCO aims to determine the suitable conditions to offload. EMCO models the evidence in terms of distributions rates for both local and remote cases. By comparing those distributions, EMCO infers the right properties to offload. EMCO shows to be more effective in comparison with other computational offloading frameworks explored in the state of the art. Finally, we investigated how computational offloading can be utilized to enhance the perception that the user has towards an app. Our main motivation behind accelerating the perception at multiple response time levels is to provide adaptive quality-of-experience (QoE), which can be used as mean of engagement strategy that increases the lifetime of a mobile app

    Mobile Ad-Hoc Networks

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    Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of-the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: quality-of-service and video communication, routing protocol and cross-layer design. A few interesting problems about security and delay-tolerant networks are also discussed. This book is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

    IP Flow Mobility in PMIPv6 Based Networks: Solution Design and Experimental Evaluation

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    The ability of offloading selected IP data traffic from 3G to WLAN access networks is considered a key feature in the upcoming 3GPP specifications, being the main goal to alleviate data congestion in cellular networks while delivering a positive user experience. Lately, the 3GPP has adopted solutions that enable mobility of IP-based wireless devices relocating mobility functions from the terminal to the network. To this end, the IETF has standardized Proxy Mobile IPv6 (PMIPv6), a protocol capable to hide often complex mobility procedures from the mobile devices. This paper, in line with the mentioned offload requirement, further extends PMIPv6 to support dynamic IP flow mobility management across access wireless networks according to operator policies. Considering energy consumption as a critical aspect for hand-held devices and smart-phones, we assess the feasibility of the proposed solution and provide an experimental analysis showing the cost (in terms of energy consumption) of simultaneous packet transmission/reception using multiple network interfaces. The end-to-end system design has been implemented and validated by means of an experimental network setup.European CommunityÂŽs Seventh Framework ProgramPublicad

    Quality-Oriented Mobility Management for Multimedia Content Delivery to Mobile Users

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    The heterogeneous wireless networking environment determined by the latest developments in wireless access technologies promises a high level of communication resources for mobile computational devices. Although the communication resources provided, especially referring to bandwidth, enable multimedia streaming to mobile users, maintaining a high user perceived quality is still a challenging task. The main factors which affect quality in multimedia streaming over wireless networks are mainly the error-prone nature of the wireless channels and the user mobility. These factors determine a high level of dynamics of wireless communication resources, namely variations in throughput and packet loss as well as network availability and delays in delivering the data packets. Under these conditions maintaining a high level of quality, as perceived by the user, requires a quality oriented mobility management scheme. Consequently we propose the Smooth Adaptive Soft-Handover Algorithm, a novel quality oriented handover management scheme which unlike other similar solutions, smoothly transfer the data traffic from one network to another using multiple simultaneous connections. To estimate the capacity of each connection the novel Quality of Multimedia Streaming (QMS) metric is proposed. The QMS metric aims at offering maximum flexibility and efficiency allowing the applications to fine tune the behavior of the handover algorithm. The current simulation-based performance evaluation clearly shows the better performance of the proposed Smooth Adaptive Soft-Handover Algorithm as compared with other handover solutions. The evaluation was performed in various scenarios including multiple mobile hosts performing handover simultaneously, wireless networks with variable overlapping areas, and various network congestion levels

    IP Flow Mobility support for Proxy Mobile IPv6 based networks

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    The ability of offloading selected IP data traffic from 3G to WLAN access networks is considered a key feature in the upcoming 3GPP specifications, being the main goal to alleviate data congestion in celular networks while delivering a positive user experience. Lately, the 3GPP has adopted solutions that enable mobility of IP-based wireless devices relocating mobility functions from the terminal to the network. To this end, the IETF has standardized Proxy Mobile IPv6 (PMIPv6), a protocol capable to hide often complex mobility procedures from the mobile devices. This thesis, in line with the mentioned offload requirement, further extends Proxy Mobile IPv6 to support dynamic IP flow mobility management across access wireless networks according to operator policies. In this work, we assess the feasibility of the proposed solution and provide an experimental analysis based on a prototype network setup, implementing the PMIPv6 protocol and the related enhancements for flow mobility support. *** La capacitĂ  di spostare flussi IP da una rete di accesso 3G ad una di tipo WLAN Ăš considerata una caratteristica chiave nelle specifiche future di 3GPP, essendo il principale metodo per alleviare la congestione nelle reti cellulari mantenendo al contempo una ragionevole qualitĂ  percepita dall'utente. Recentemente, 3GPP ha adottato soluzioni di mobilitĂ  per dispositivi con accesso radio basato su IP, traslando le funzioni di supporto dal terminale alla rete, e, a questo scopo, IETF ha standardizzato Proxy Mobile IPv6 (PMIPv6), un protocollo studiato per nascondere le procedure di mobilitĂ  ai sistemi mobili. Questa tesi, in linea con la citata esigenza di spostare flussi IP, estende ulteriormente PMIPv6 per consentire il supporto alla mobilitĂ  di flussi tra diverse reti di accesso wireless, assecondando le regole e/o politiche definite da un operatore. In questo lavoro, ci proponiamo di asserire la fattibilitĂ  della soluzione proposta, fornendo un'analisi sperimentale di essa sulla base di un prototipo di rete che implementa il protocollo PMIPv6 e le relative migliorie per il supporto alla mobilitĂ  di flussiope

    Energy-Efficient Softwarized Networks: A Survey

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    With the dynamic demands and stringent requirements of various applications, networks need to be high-performance, scalable, and adaptive to changes. Researchers and industries view network softwarization as the best enabler for the evolution of networking to tackle current and prospective challenges. Network softwarization must provide programmability and flexibility to network infrastructures and allow agile management, along with higher control for operators. While satisfying the demands and requirements of network services, energy cannot be overlooked, considering the effects on the sustainability of the environment and business. This paper discusses energy efficiency in modern and future networks with three network softwarization technologies: SDN, NFV, and NS, introduced in an energy-oriented context. With that framework in mind, we review the literature based on network scenarios, control/MANO layers, and energy-efficiency strategies. Following that, we compare the references regarding approach, evaluation method, criterion, and metric attributes to demonstrate the state-of-the-art. Last, we analyze the classified literature, summarize lessons learned, and present ten essential concerns to open discussions about future research opportunities on energy-efficient softwarized networks.Comment: Accepted draft for publication in TNSM with minor updates and editin

    Design and Implementation of a Communication Protocol to Improve Multimedia QoS and QoE in Wireless Ad Hoc Networks

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    [EN] This dissertation addresses the problem of multimedia delivery over multi-hop ad hoc wireless networks, and especially over wireless sensor networks. Due to their characteristics of low power consumption, low processing capacity and low memory capacity, they have major difficulties in achieving optimal quality levels demanded by end users in such communications. In the first part of this work, it has been carried out a study to determine the behavior of a variety of multimedia streams and how they are affected by the network conditions when they are transmitted over topologies formed by devices of different technologies in multi hop wireless ad hoc mode. To achieve this goal, we have performed experimental tests using a test bench, which combine the main codecs used in audio and video streaming over IP networks with different sound and video captures representing the characteristic patterns of multimedia services such as phone calls, video communications, IPTV and video on demand (VOD). With the information gathered in the laboratory, we have been able to establish the correlation between the induced changes in the physical and logical topology and the network parameters that measure the quality of service (QoS) of a multimedia transmission, such as latency, jitter or packet loss. At this stage of the investigation, a study was performed to determine the state of the art of the proposed protocols, algorithms, and practical implementations that have been explicitly developed to optimize the multimedia transmission over wireless ad hoc networks, especially in ad hoc networks using clusters of nodes distributed over a geographic area and wireless sensor networks. Next step of this research was the development of an algorithm focused on the logical organization of clusters formed by nodes capable of adapting to the circumstances of real-time traffic. The stated goal was to achieve the maximum utilization of the resources offered by the set of nodes that forms the network, allowing simultaneously sending reliably and efficiently all types of content through them, and mixing conventional IP data traffic with multimedia traffic with stringent QoS and QoE requirements. Using the information gathered in the previous phase, we have developed a network architecture that improves overall network performance and multimedia streaming. In parallel, it has been designed and programmed a communication protocol that allows implementing the proposal and testing its operation on real network infrastructures. In the last phase of this thesis we have focused our work on sending multimedia in wireless sensor networks (WSN). Based on the above results, we have adapted both the architecture and the communication protocol for this particular type of network, whose use has been growing hugely in recent years.[ES] Esta tesis doctoral aborda el problema de la distribuciĂłn de contenidos multimedia a travĂ©s de redes inalĂĄmbricas ad hoc multisalto, especialmente las redes inalĂĄmbricas de sensores que, debido a sus caracterĂ­sticas de bajo consumo energĂ©tico, baja capacidad de procesamiento y baja capacidad de memoria, plantean grandes dificultades para alcanzar los niveles de calidad Ăłptimos que exigen los usuarios finales en dicho tipo de comunicaciones. En la primera parte de este trabajo se ha llevado a cabo un estudio para determinar el comportamiento de una gran variedad de flujos multimedia y como se ven afectados por las condiciones de la red cuando son transmitidos a travĂ©s topologĂ­as formadas por dispositivos de diferentes tecnologĂ­as que se comunican en modo ad hoc multisalto inalĂĄmbrico. Para ello, se han realizado pruebas experimentales sobre una maqueta de laboratorio, combinando los principales cĂłdecs empleados en la transmisiĂłn de audio y video a travĂ©s de redes IP con diversas capturas de sonido y video que representan patrones caracterĂ­sticos de servicios multimedia tales como las llamadas telefĂłnicas, videoconferencias, IPTV o video bajo demanda (VOD). Con la informaciĂłn reunida en el laboratorio se ha podido establecer la correlaciĂłn entre los cambios inducidos en la topologĂ­a fĂ­sica y lĂłgica de la red con los parĂĄmetros que miden la calidad de servicio (QoS) de una transmisiĂłn multimedia, tales como la latencia el jitter o la pĂ©rdida de paquetes. En esta fase de la investigaciĂłn se realiza un estudio para determinar el estado del arte de las propuestas de desarrollo e implementaciĂłn de protocolos y algoritmos que se han generado de forma explĂ­cita para optimizar la transmisiĂłn de trĂĄfico multimedia sobre redes ad hoc inalĂĄmbricas, especialmente en las redes inalĂĄmbricas de sensores y redes ad hoc utilizando clĂșsteres de nodos distribuidos en un espacio geogrĂĄfico. El siguiente paso en la investigaciĂłn ha consistido en el desarrollo de un algoritmo propio para la organizaciĂłn lĂłgica de clĂșsteres formados por nodos capaces de adaptarse a las circunstancias del trĂĄfico en tiempo real. El objetivo planteado es conseguir un aprovechamiento mĂĄximo de los recursos ofrecidos por el conjunto de nodos que forman la red, permitiendo de forma simultĂĄnea el envĂ­o de todo tipo de contenidos a travĂ©s de ellos de forma confiable y eficiente, permitiendo la convivencia de trĂĄfico de datos IP convencional con trĂĄfico multimedia con requisitos exigentes de QoS y QoE. A partir de la informaciĂłn conseguida en la fase anterior, se ha desarrollado una arquitectura de red que mejora el rendimiento general de la red y el de las transmisiones multimedia de audio y video en particular. De forma paralela, se ha diseñado y programado un protocolo de comunicaciĂłn que permite implementar el modelo y testear su funcionamiento sobre infraestructuras de red reales. En la Ășltima fase de esta tesis se ha dirigido la atenciĂłn hacia la transmisiĂłn multimedia en las redes de sensores inalĂĄmbricos (WSN). Partiendo de los resultados anteriores, se ha adaptado tanto la arquitectura como el protocolo de comunicaciones para este tipo concreto de red, cuyo uso se ha extendido en los Ășltimos años de forma considerable[CA] Esta tesi doctoral aborda el problema de la distribuciĂł de continguts multimĂšdia a travĂ©s de xarxes sense fil ad hoc multi salt, especialment les xarxes sense fil de sensors que, a causa de les seues caracterĂ­stiques de baix consum energĂštic, baixa capacitat de processament i baixa capacitat de memĂČria, plantegen grans dificultats per a aconseguir els nivells de qualitat ĂČptims que exigixen els usuaris finals en eixos tipus de comunicacions. En la primera part d'este treball s'ha dut a terme un estudi per a determinar el comportament d'una gran varietat de fluxos multimĂšdia i com es veuen afectats per les condicions de la xarxa quan sĂłn transmesos a travĂ©s topologies formades per dispositius de diferents tecnologies que es comuniquen en mode ad hoc multi salt sense fil. Per a aixĂČ, s'han realitzat proves experimentals sobre una maqueta de laboratori, combinant els principals cĂłdecs empleats en la transmissiĂł d'Ă udio i vĂ­deo a travĂ©s de xarxes IP amb diverses captures de so i vĂ­deo que representen patrons caracterĂ­stics de serveis multimĂšdia com son les cridades telefĂČniques, videoconferĂšncies, IPTV o vĂ­deo baix demanda (VOD). Amb la informaciĂł reunida en el laboratori s'ha pogut establir la correlaciĂł entre els canvis induĂŻts en la topologia fĂ­sica i lĂČgica de la xarxa amb els parĂ metres que mesuren la qualitat de servei (QoS) d'una transmissiĂł multimĂšdia, com la latĂšncia el jitter o la pĂšrdua de paquets. En esta fase de la investigaciĂł es realitza un estudi per a determinar l'estat de l'art de les propostes de desenvolupament i implementaciĂł de protocols i algoritmes que s'han generat de forma explĂ­cita per a optimitzar la transmissiĂł de trĂ fic multimĂšdia sobre xarxes ad hoc sense fil, especialment en les xarxes sense fil de sensors and xarxes ad hoc utilitzant clusters de nodes distribuĂŻts en un espai geogrĂ fic. El segĂŒent pas en la investigaciĂł ha consistit en el desenvolupament d'un algoritme propi per a l'organitzaciĂł lĂČgica de clusters formats per nodes capaços d'adaptar-se a les circumstĂ ncies del trĂ fic en temps real. L'objectiu plantejat Ă©s aconseguir un aprofitament mĂ xim dels recursos oferits pel conjunt de nodes que formen la xarxa, permetent de forma simultĂ nia l'enviament de qualsevol tipus de continguts a travĂ©s d'ells de forma confiable i eficient, permetent la convivĂšncia de trĂ fic de dades IP convencional amb trĂ fic multimĂšdia amb requisits exigents de QoS i QoE. A partir de la informaciĂł aconseguida en la fase anterior, s'ha desenvolupat una arquitectura de xarxa que millora el rendiment general de la xarxa i el de les transmissions multimĂšdia d'Ă udio i vĂ­deo en particular. De forma paralÂżlela, s'ha dissenyat i programat un protocol de comunicaciĂł que permet implementar el model i testejar el seu funcionament sobre infraestructures de xarxa reals. En l'Ășltima fase d'esta tesi s'ha dirigit l'atenciĂł cap a la transmissiĂł multimĂšdia en les xarxes de sensors sense fil (WSN). Partint dels resultats anteriors, s'ha adaptat tant l'arquitectura com el protocol de comunicacions per a aquest tipus concret de xarxa, l'Ășs del qual s'ha estĂ©s en els Ășltims anys de forma considerable.DĂ­az Santos, JR. (2016). Design and Implementation of a Communication Protocol to Improve Multimedia QoS and QoE in Wireless Ad Hoc Networks [Tesis doctoral no publicada]. Universitat PolitĂšcnica de ValĂšncia. https://doi.org/10.4995/Thesis/10251/62162TESI
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