1,720,995 research outputs found
64-APSK Constellation and Mapping Optimization for Satellite Broadcasting Using Genetic Algorithms
No full textDVB-S2 and DVB-SH satellite broadcasting standards currently deploy 16-And 32-Amplitude phase shift keying (APSK) modulation using the consultative committee for space data systems (CCSDS) mapping. Such standards also include hierarchical modulation as a mean to provide unequal error protection in highly variable channels over satellite. Foreseeing the increasing need for higher data rates, this paper tackles the optimization of 64-APSK constellations to minimize the mean square error between the original and received symbol. Optimization is performed according to the sensitivity of the data to the channel errors, by means of genetic algorithms, a well-known technique currently used in a variety of application domains, when close form solutions are impractical. Test results show that through non-uniform constellation and asymmetric symbol mapping, it is possible to significantly reduce the distortion while preserving bandwidth efficiency. Tests performed on real signals based on perceptual quality measurements allow validating the proposed scheme against conventional 64-APSK constellations and CCSDS mapping
A Novel Markov Decision Process-Based Solution for Improved Quality Prioritized Video Delivery
No full textThe recent growth in both number of high specification mobile devices and network multimedia data demand, has made difficult supporting access to the multimedia content at high user Quality of Experience (QoE) levels. It is even more challenging to support offering such services adjusted to user specific requirements in current heterogeneous wireless network environments (HWNE). This paper proposes a novel Prioritized Adaptive Real-time Multi-user Access Network Selection framework (P-ARMANS) which employs a Markov Decision Process (MDP) solution to perform improved bandwidth resource allocation. P-ARMANS enables load balancing during multimedia delivery when users with diverse priority and different device screen resolutions access various services. Modeling and simulations show how P-ARMANS distributes content with different types of traffic and load among typical and business users at higher QoE levels compared to a classic no-priority approach
E-ARMANS: Energy-aware device-oriented video delivery in heterogeneous wireless networks
No full textThe latest technological development of smartphones and tablets has supported an exponential increase in demand for multimedia content from their users. At the same time, the battery-related technologies for these devices have not advanced at the same pace and are an important limitation factor for future developments. Therefore there is a need for energy-aware solutions for multimedia delivery to such mobile devices and this paper focuses on energy saving in the context of multimedia distribution at high quality levels over loaded heterogeneous wireless networks. The paper proposes an energy-aware device-oriented video delivery algorithm (E-ARMANS) as a solution to a twofold problem: Traffic load balancing over wireless networks and energy consumption optimization. E-ARMANS evaluates both network conditions and device characteristics and provides the user the best connectivity in given conditions. Testing in comparison with a performance-oriented approach shows how E-ARMANS increases average battery life with 40%, 47%, and 32%, while delivering video content to devices with 1080p, 720p, and 576p resolutions, respectively
Heuristic performance evaluation for DVB-T/T2 SFN network
No full textIn DVB-T/T2 broadcasting single frequency network (SFN) multipath interference (MPI) at the receiver antenna is a critical issue. The capability to elaborate those signals depends on both synchronization strategy used and coded orthogonal frequency-division multiplexing (COFDM) modulation properties. An efficient COFDM system requires the guard interval as short as possible and such as to protect the system from the MPI. To cope with this problem a static delay adjustment obtained by fitting the launching time of each broadcast station is introduced so that the time difference of the incoming signals within the reception area falls into the COFDM guard interval. This work investigates the use of advanced simulated annealing to optimize transmission parameters such as the static delay, gain and orientation of sector antennas of DVB-T/T2 transmitters in SFNs. In particular, we identify the static delay adjustment map to maximize the coverage area according to quality of service requirements. The proposed approach has been validated for DVB-T/T2 network planning in the Basque Country (Spain) and Sardinia island (Italy). Different density of transmitters, generalized geography of territory are considered for the best setting of the parameters involved. Reliability studies are included to demonstrate the efficacy of the method
Enabling a Scalable and Adaptive Cloud Infrastructure for Virtual Users in the Social Internet of Things
No full textThe Internet of Things (IoT) is a global network of intelligent interconnected objects, enabling remote recognition, detection, and control. Through virtualization, these devices exchange knowledge in the Cloud, bridging physical and virtual worlds. However, the rapid growth in connected objects and data production necessitates innovative system designs. While virtualization offers scalability and flexibility, it proves insufficient alone. Recent studies recommend integrating social network concepts into IoT, forming the Social Internet of Things (SIoT). SIoT, mirroring human social networks, enhances smart devices with relational capabilities, addressing challenges in managing the surge in connected devices. This paper introduces the "Virtual User" concept-an autonomous entity streamlining user-device interactions in the digital realm. The research proposes, elucidates, and evaluates a Cloud infrastructure integrating the Virtual User into the SIoT paradigm. This novel approach offers a modular, extendable, and secure communication platform, marking the first Cloud solution tailored for the Virtual User concept, leveraging SIoT virtualization through containerization and automated service setup processes
Real-time load optimization for multimedia delivery content over heterogeneuos wireless network using a MEW approach
No full textThe significant increment in the number of users that need broadband multimedia system, relative radio resources, and the evolution of the devices has encouraged to search for different methods to manage heterogeneous wireless networks. One solution to this problem is to make traffic balancing on heterogeneous networks, so that none of the available networks for a given user will be saturated avoiding performance decay. This paper proposes a novel Multiplicative Exponential Weighting (MEW) approach that manages the access network selection. MEW combines several inputs such as power of the received signal, throughput, packet delay, cost-per-user, the requested type of traffic, and type of device. The obtained results have shown an improvement of 15% in average PSNR, and 20% in terms of delay and throughput, compared to the algorithms presented in the literature
QoE Assessment for IoT-Based Multi Sensorial Media Broadcasting
No full textOne of the goals of next generation TV broadcast services is to provide realistic media contents to the users. The user's sense of reality can be reinforced by adding to conventional media multiple sensorial effects, through five-sense stimulus (i.e., taste, sight, touch, smell, and hearing). In a smart TV broadcasting context, especially in a home environment, to deliver the additional effects, customary devices (e.g., air conditioning, lights, etc.), provided of opportune smart features, have to be preferred to ad-hoc devices, often deployed in other applications as for example in gaming systems. In this context, a key issue is the interconnection among the smart TV and the customary devices that deliver the additional sensorial effects to the user. In smart home use cases, the Internet of Things (IoT) paradigm has been widely adopted to connect smart devices and this paper presents an IoT-based architecture for multi sensorial media delivery to TV users in a home entertainment scenario. In such a framework, home customary devices, act as smart objects interconnected via IoT network to the smart TV and play a role to implement additional effects to the conventional broadcast TV service. In this paper, the requirements in terms of synchronization between media and devices is analyzed and the architecture of the system is defined accordingly. Furthermore, a prototype is implemented in a real smart home scenario with real customary devices, which allowed a subjective test measurement campaign to assess the quality of experience of the users and the feasibility of the proposed multi sensorial media TV service
QoE Assessment for Broadcasting Multi Sensorial Media in Smart Home Scenario
No full textOne of the goals of future TV broadcast services is to provide realistic media contents to the users. The user's sense of reality can be reinforced by adding to conventional media multiple sensorial effects, through five-sense stimulus (i.e., taste, sight, touch, smell, and hearing). In a smart home environment, to deliver the additional effects, customary devices (e.g., air conditioning, lights, etc.), provided of opportune smart features, have to be preferred to ad-hoc devices, often deployed in other applications as for example in gaming systems. In this context, a key issue is the interconnection among the TV and the customary devices that deliver the additional sensorial effects to the user. In such a framework, home customary devices play a role to implement additional effects to the conventional broadcast TV service. In this study, a prototype is implemented for broadcasting multi sensorial media in a real smart home scenario. Real customary devices are deployed. A subjective test measurement campaign based on mean opinion score was performed to assess the Quality of Experience of the users and the feasibility of the proposed multi sensorial media TV service
Internet of Things for Enabling Multi Sensorial TV in Smart Home
No full textThis paper presents the results of a subjective test campaign performed on a real smart home scenario and aimed at assessing the enrichment of the quality of experience of real users. A proof of concept of an IoT based architecture deploying customary devices in a smart home environment is implemented and used for test assessments. If opportunely embedded on the content stream or in the broadcasting transmission technology, multi sensorial meta data could be interpreted by a smart TV and used in a smart home environment to provide users with an enriched TV experience, via the proposed IoT architecture
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