342 research outputs found
An autonomic delivery framework for HTTP adaptive streaming in multicast-enabled multimedia access networks
The consumption of multimedia services over HTTP-based delivery mechanisms has recently gained popularity due to their increased flexibility and reliability. Traditional broadcast TV channels are now offered over the Internet, in order to support Live TV for a broad range of consumer devices. Moreover, service providers can greatly benefit from offering external live content (e. g., YouTube, Hulu) in a managed way. Recently, HTTP Adaptive Streaming (HAS) techniques have been proposed in which video clients dynamically adapt their requested video quality level based on the current network and device state. Unlike linear TV, traditional HTTP- and HAS-based video streaming services depend on unicast sessions, leading to a network traffic load proportional to the number of multimedia consumers. In this paper we propose a novel HAS-based video delivery architecture, which features intelligent multicasting and caching in order to decrease the required bandwidth considerably in a Live TV scenario. Furthermore we discuss the autonomic selection of multicasted content to support Video on Demand (VoD) sessions. Experiments were conducted on a large scale and realistic emulation environment and compared with a traditional HAS-based media delivery setup using only unicast connections
A QoE based performance study of mobile peer-to-peer live video streaming
Peer-to-peer (P2P) Mobile Ad Hoc Networks (MANETs) are widely envisioned to be a practical platform to mobile live video streaming applications (e.g., mobile IPTV). However, the performance of such a streaming solution is still largely unknown. As such, in this paper, we aim to quantify the streaming performance using a Quality of Experience (QoE) based approach. Our simulation results indicate that video streaming performance is highly sensitive to the video chunk size. Specifically, if the chunk size is small, performance, in terms of both QoE and QoS, is guaranteed but at the expense of a higher overhead. On the other hand, if chunk size is increased, performance can degrade quite rapidly. Thus, it needs some careful fine tuning of chunk size to obtain satisfactory QoE performance. © 2012 IEEE.published_or_final_versio
Towards video streaming in IoT environments: vehicular communication perspective
Multimedia oriented Internet of Things (IoT) enables pervasive and real-time communication of video, audio and image data among devices in an immediate surroundings. Today's vehicles have the capability of supporting real time multimedia acquisition. Vehicles with high illuminating infrared cameras and customized sensors can communicate with other on-road devices using dedicated short-range communication (DSRC) and 5G enabled communication technologies. Real time incidence of both urban and highway vehicular traffic environment can be captured and transmitted using vehicle-to-vehicle and vehicle-to-infrastructure communication modes. Video streaming in vehicular IoT (VSV-IoT) environments is in growing stage with several challenges that need to be addressed ranging from limited resources in IoT devices, intermittent connection in vehicular networks, heterogeneous devices, dynamism and scalability in video encoding, bandwidth underutilization in video delivery, and attaining application-precise quality of service in video streaming. In this context, this paper presents a comprehensive review on video streaming in IoT environments focusing on vehicular communication perspective. Specifically, significance of video streaming in vehicular IoT environments is highlighted focusing on integration of vehicular communication with 5G enabled IoT technologies, and smart city oriented application areas for VSV-IoT. A taxonomy is presented for the classification of related literature on video streaming in vehicular network environments. Following the taxonomy, critical review of literature is performed focusing on major functional model, strengths and weaknesses. Metrics for video streaming in vehicular IoT environments are derived and comparatively analyzed in terms of their usage and evaluation capabilities. Open research challenges in VSV-IoT are identified as future directions of research in the area. The survey would benefit both IoT and vehicle industry practitioners and researchers, in terms of augmenting understanding of vehicular video streaming and its IoT related trends and issues
DecVi: Adaptive Video Conferencing on Open Peer-to-Peer Networks
Video conferencing has become the preferred way of interacting virtually.
Current video conferencing applications, like Zoom, Teams or WebEx, are
centralized, cloud-based platforms whose performance crucially depends on the
proximity of clients to their data centers. Clients from low-income countries
are particularly affected as most data centers from major cloud providers are
located in economically advanced nations. Centralized conferencing applications
also suffer from occasional outages and are embattled by serious privacy
violation allegations. In recent years, decentralized video conferencing
applications built over p2p networks and incentivized through blockchain are
becoming popular. A key characteristic of these networks is their openness:
anyone can host a media server on the network and gain reward for providing
service. Strong economic incentives combined with lower entry barrier to join
the network, makes increasing server coverage to even remote regions of the
world. These reasons, however, also lead to a security problem: a server may
obfuscate its true location in order to gain an unfair business advantage. In
this paper, we consider the problem of multicast tree construction for video
conferencing sessions in open p2p conferencing applications. We propose DecVi,
a decentralized multicast tree construction protocol that adaptively discovers
efficient tree structures based on an exploration-exploitation framework. DecVi
is motivated by the combinatorial multi-armed bandit problem and uses a
succinct learning model to compute effective actions. Despite operating in a
multi-agent setting with each server having only limited knowledge of the
global network and without cooperation among servers, experimentally we show
DecVi achieves similar quality-of-experience compared to a centralized globally
optimal algorithm while achieving higher reliability and flexibility
A credit-based approach to scalable video transmission over a peer-to-peer social network
PhDThe objective of the research work presented in this thesis is to study
scalable video transmission over peer-to-peer networks. In particular,
we analyse how a credit-based approach and exploitation of social networking
features can play a significant role in the design of such systems.
Peer-to-peer systems are nowadays a valid alternative to the traditional
client-server architecture for the distribution of multimedia content, as
they transfer the workload from the service provider to the final user,
with a subsequent reduction of management costs for the former. On
the other hand, scalable video coding helps in dealing with network
heterogeneity, since the content can be tailored to the characteristics
or resources of the peers. First of all, we present a study that evaluates
subjective video quality perceived by the final user under different
transmission scenarios. We also propose a video chunk selection algorithm
that maximises received video quality under different network
conditions. Furthermore, challenges in building reliable peer-to-peer
systems for multimedia streaming include optimisation of resource allocation
and design mechanisms based on rewards and punishments that
provide incentives for users to share their own resources. Our solution
relies on a credit-based architecture, where peers do not interact with
users that have proven to be malicious in the past. Finally, if peers
are allowed to build a social network of trusted users, they can share
the local information they have about the network and have a more
complete understanding of the type of users they are interacting with.
Therefore, in addition to a local credit, a social credit or social reputation
is introduced. This thesis concludes with an overview of future
developments of this research work
Scalable Media Coding Enabling Content-Aware Networking
Increasingly popular multimedia services are expected to play a dominant role in the future of the Internet. In this context, it is essential that content-aware networking (CAN) architectures explicitly address the efficient delivery and processing of multimedia content. This article proposes the adoption of a content-aware approach into the network infrastructure, thus making it capable of identifying, processing, and manipulating media streams and objects in real time to maximize quality of service (QoS) and experience (QoE). Our proposal is built on the exploitation of scalable media coding technologies within such a content-aware networking environment. This discussion is based on four representative use cases for media delivery (unicast, multicast, peer-to-peer, and adaptive HTTP streaming) and reviews CAN challenges, specifically flow processing, caching/buffering, and QoS/QoE management
Adaptive Streaming: A subjective catalog to assess the performance of objective QoE metrics
Scalable streaming has emerged as a feasible solution to resolve users' heterogeneity problems. SVC is the technology that has served as the definitive impulse for the growth of streaming adaptive systems. Systems seek to improve layer switching efficiency from the network point of view but, with increasing importance, without jeopardizing user perceived video quality, i.e., QoE. We have performed extensive subjective experiments to corroborate the preference towards adaptive systems when compared to traditional non-adaptive systems. The resulting subjective scores are correlated with most relevant Full Reference (FR) objective metrics. We obtain an exponential relationship between human decisions and the same decisions expressed as a difference of objective metrics. A strong correlation with subjective scores validates objective metrics to be used as aid in the adaptive decision taking algorithms to improve overall systems performance. Results show that, among the evaluated objective metrics, PSNR is the metric that provide worse results in terms of reproducing the human decision
Geographical forwarding algorithm based video content delivery scheme for internet of vehicles (IoV)
This is an accepted manuscript of an article published by IEEE Multimedia Communications Technical Committee in MMTC Communications â Frontiers on 31/07/2020, available online: https://mmc.committees.comsoc.org/files/2020/07/MMTC_Communication_Frontier_July_2020.pdf
The accepted version of the publication may differ from the final published version.An evolved form of Vehicular Ad hoc Networks (VANET) has recently emerged as the Internet of Vehicles (IoV). Though, there
are still some challenges that need to be addressed in support IoV applications. The objective of this research is to achieve an
efficient video content transmission over vehicular networks. We propose a balanced video-forwarding algorithm for delivering
video-based content delivery scheme. The available neighboring vehicles will be ranked to the vehicle in forwarding progress
before transmitting the video frames using proposed multi-score function. Considering the current beacon reception rate,
forwarding progress and direction to destination, in addition to residual buffer length; the proposed algorithm can elect the best
candidate to forward the video frames to the next highest ranked vehicles in a balanced way taking in account their residual buffer
lengths. To facilitate the proposed video content delivery scheme, an approach of H.264/SVC was improvised to divide video
packets into various segments, to be delivered into three defined groups. These created segments can be encoded and decoded
independently and integrated back to produce the original packet sent by source vehicle. Simulation results demonstrate the
efficiency of our proposed algorithm in improving the perceived video quality compared with other approache
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