1,721,014 research outputs found
Broadcasting of digital cimema streams over wireless channels: A power-based Unequal Error Protection approach
No full textThis paper presents a wavelet transmultiplexer based communication system for the transmission of Digital Cinema streams over wireless channels. To this aim, we adopt the tools of the JPEG2000 Wireless (JPWL) standard. We implement an unequal error protection (UEP) scheme that relies on forward error correction (FEC) channel coding supported by a proper unequal distribution of the transmission power (UPD) among JPWL coding units. In particular, we show that an appropriate combination of Reed-Solomon (RS) coding and UPD on the image data, can greatly improve the average PSNR of the reconstructed frames, in case of transmission over wireless channels with both sparse and packet error statistics, such as those provided by satellite broadcasting and Wireless MAN standards as WiMAX. Copyright 2006 ACM
The Impact of Multi-Sensorial Media in Smart Home Scenario on User Experience and Emotions
No full textThe traditional multimedia contents only stimulate sight and hearing human senses. Therefore, the research efforts try to provide realistic media contents to the users to stimulate the other senses, realistic media contents are media with multiple sensorial effects, with the aim of increasing user's sense of reality and emotions strength through the five senses representation. In home environment, to deliver the additional effects, customary devices (e.g., air conditioning, lights, smartphones, etc.), provided of opportune smart features, can be deployed. In smart home use cases, the Internet of Things (IoT) paradigm has been widely adopted to connect smart devices. This paper presents user perception of IoT-based multi-sensorial media delivery to TV users in home entertainment scenario, through subjective test measurement campaign. In particular we analyzed the influence of three sensory effects (i.e., airflow, lights and vibration) on user annoyance, emotions, sense of reality, and if users consider the sensory effects distracting, through presenting ten audiovisual sequences that contain different emotions like surprise, anger, fear, fun, and worry, which people commonly use to describe emotions in audiovisual sequences. The participants' response employed to reveal the impact of sensory effects on user experience
Extremely High Frequency (EHF) Bands for Future Broadcast Satellite Services: Opportunities and Challenges
Full text linkThe exploitation of the bandwidth portions in the millimeter wave domain, namely extremely high frequencies (EHFs) will open new perspectives to future satellite services, in particular for high quality TV broadcasting and multimedia content delivery. The present work aims at surveying the opportunities and challenges of EHF exploitation for broadband satellite applications in the broadcast framework. Theoretical capacity evaluation confirms that EHF satellite links can offer unprecedented data-rates, clearly superior than that actually provided by Ku and Ka-bands. However, some crucial issues are still to be solved, mainly in terms of mitigation of tropospheric propagation impairments and appropriate waveform design. Link and capacity analysis will be the basis for the investigation of future application scenarios of broadcast EHF satcoms, namely high-definition TV (HDTV) and ultra-HDTV, with particular emphasis to 4K and 8K video formats
Interference measurements for unlicensed 802.11p communication in the TV bands
No full textIn the context of the gradual passage to digital terrestrial television, the unused channels within the TV operation bands can be an ideal candidate to implement short-range and low-power communication systems for vehicular ad hoc networks based on the IEEE 802.11p communication standard. This work presents a study on the adjacent channel interference caused by IEEE 802.11p system operating into the same coverage range of a DVB-T2 receiver
Robust multi-rate modulation for cognitive radio communications over land mobile satellite channel at Ku-band
No full textThe usable satellite spectrum is becoming scarce because of continuously increasing demand for broadcast, multimedia and interactive services. Because of the extensive use of predictive coding, multimedia data exhibit different sensitivities to transmission errors, which makes them suitable for unequal error protection (UEP) techniques. UEP mainly relies on differentiated error control coding which raises the robustness of data, but also increases the transmission bandwidth, which can be unwanted in case of limited resources often occurring in satellite communications. In this context, cognitive radio (CR) satellite communications has received important attention lately in the research community. In multi-rate modulations (MRM), the properties of dy-homogeneous signals are exploited to transmit over multiple band frequencies and time scales. MRM have been proved to be effective on unknown channels either in bandwidth or time. These conditions occur in CR networks where opportunistic communications are set up while preserving primaries licensed users. In CR, the uncertainty of transmission opportunity makes the use of error correcting codes not trivial. Therefore, to achieve robustness, this work proposes unequal power allocation (UPA) over the symbols of MRM according to both data sensitivity to channel errors and spectrum availability. As optimization criterion, the mean square error between the original and the decoded message, which has shown strong correlation with subjective perception, is used. To assess the effectiveness of the proposed scheme in realistic condition for CR satellite networks, the Land Mobile Satellite (LMS) model at Ku-band is used to reproduce the memory associated with real channels. The non-linearity of the satellite channel because of high power amplifier (HPA) prior to transmission has been accounted using the Saleh model. Copyright © 2016 John Wiley & Sons, Ltd
On the Suitability of HbbTV for Unified Smart Home Experience
No full textHybrid broadcast broadband TV (HbbTV) is a standardization initiative aimed at harmonising the broadcast and broadband delivery of entertainment services to consumers through connected TVs, set-top boxes, and multiscreen devices. A smart home (SH) is a suitable home setup where appliances and devices can be automatically controlled remotely from any Internet-connected device. For the seamless integration of a variety of devices within the SH, HbbTV solutions are gaining a pivotal role, acting as a central hub for audio and video broadcasting services, home automation and other devices, including smartphones, tablets and Internet of Things (IoT)-enabled devices. In this context, a standard, compliant and platform independent, solution is preferred as it can enable dynamic environment where heterogeneous devices contribute to the overall user experience. This paper proposes an architecture for the seamless integration of a SH environment with a HbbTV-enabled television set and consumer's handled devices, such as smartphones and tablets, using the HbbTV 2.0.1 Companions Screen and Multimedia Synchronization framework. A complete architectural design and its hardware implementation have been developed and deployed as a proof of concept. Subjective tests based on mean opinion score (MOS) have been conducted to assess the benefits of the proposed system in terms of Quality of Experience (QoE). Results are encouraging and show that the accurate design of hybrid services through HbbTV could lead to satisfactory QoE perceived by users in the fruition of unified TV and SH services. Based on the obtained results, a preferred common configuration of notifications in terms of position, duration, and sound was indicated
Multicasting Over 6G Non-Terrestrial Networks: A Softwarization-Based Approach
Full text linkMulticast/broadcast delivery is a critical challenge of future 6G mobile networks where massive Internet of Things (IoT) deployment and extended reality multimedia such as teleportation are target application scenarios. Non-terrestrial networks (NTNs) are considered essential for the success of 6G, which aims to provide true 'global' services by extending mobile access worldwide, thus overcoming the coverage limit of current terrestrial networks (TNs). This article discusses how the main distinguishing features of NTNs can be effectively exploited for 6G multicasting. Furthermore, in line with the evolution of future 6G networks toward softwarized systems, we evaluate the potential of using the softwarization paradigm in the heterogeneous TN-NTN architecture to deliver multicast services
Mobility aware eMBMS management in urban 5G-oriented systems
No full textThe demand for video services in mobile networks is rapidly increasing. In fact, is expected that video transmissions will account for more than 69% of mobile data traffic by 2018[1]. Along these lines, the challenging requirements of such multimedia applications and, at the same time, the centralized organization typical of current cellular technologies motivate the investigation of enhanced advanced driver assistance systems (ADAS) for supporting the driver experience in terms of safety driving comfort. In this context, in this paper we focus our attention of a new realistic scenario, in which all users share video contents from the surrounding environment with the aim to create a global 3D video content useful for ADAS systems. Once that such video content is created, we assume that the LTE eNodeB may come in help for making it available through streaming transmissions towards all vehicles in that area with the use of Multimedia Broadcast Multicast Services (MBMS). Obtained results, show that multicast transmissions based on subgrouping techniques are able to overcome the legacy solutions where conservative and opportunistic schemes are used
Self - Configurable IoT Satellite Gateway with QoS Traffic Management
No full textInternet-of- Things (IoT) represents a breakthrough for the current ICI market. In many IoT applications, sensors and actuators are distributed over very wide areas, sometimes not reached by terrestrial networks. In such scenarios, called Internet-of-Remote- Things (IoRT) the satellite can play a significant role. This paper presents the hardware implementation and functional test of a gateway for IoRT, along with its operational characteristics. In particular, it focuses on the self-configurability of the proposed gateway and on the QoS-based traffic management in the context of IoRT. The functional analysis of the proposed architecture is performed at 'proof-of-concept' level, without open-field testing that would require the presence of an operational satellite link
Dynamic Radio Access Selection and Slice Allocation for Differentiated Traffic Management on Future Mobile Networks
Full text linkThe development of future wireless networks focuses on providing services with strict, dynamic, and diverse quality of service (QoS) requirements. In this sense, the network slicing paradigm arises as a critical piece on the efficient allocation and management of network resources, allowing for dividing the network into several logical networks with specific functionalities and performance. This paper aims at finding the best combination of access network and network slices over a heterogeneous environment to fulfill users’ requests and optimize network resources usage. We propose the Dynamic radio Access selection and Slice Allocation (DASA) algorithm, flexibly adapted to network conditions, user priorities, and mobility behavior. DASA is based on a multi-attribute decision making (MADM) and analytical hierarchy process (AHP) to face the complex problem of network selection. Moreover, it uses a cooperative game theory approach to handle load balancing during overload situations. This work presents an integral solution that combines software-defined network (SDN) and network function virtualization (NFV) technologies to improve network performance and user satisfaction. DASA algorithm is evaluated through network-level simulations, focusing on flexibility and the effective utilization of network resources during network selection and load balancing mechanisms
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