68 research outputs found

    Video-on-Demand over Internet: a survey of existing systems and solutions

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    Video-on-Demand is a service where movies are delivered to distributed users with low delay and free interactivity. The traditional client/server architecture experiences scalability issues to provide video streaming services, so there have been many proposals of systems, mostly based on a peer-to-peer or on a hybrid server/peer-to-peer solution, to solve this issue. This work presents a survey of the currently existing or proposed systems and solutions, based upon a subset of representative systems, and defines selection criteria allowing to classify these systems. These criteria are based on common questions such as, for example, is it video-on-demand or live streaming, is the architecture based on content delivery network, peer-to-peer or both, is the delivery overlay tree-based or mesh-based, is the system push-based or pull-based, single-stream or multi-streams, does it use data coding, and how do the clients choose their peers. Representative systems are briefly described to give a summarized overview of the proposed solutions, and four ones are analyzed in details. Finally, it is attempted to evaluate the most promising solutions for future experiments. Résumé La vidéo à la demande est un service où des films sont fournis à distance aux utilisateurs avec u

    Enabling Large-Scale Peer-to-Peer Stored Video Streaming Service with QoS Support

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    This research aims to enable a large-scale, high-volume, peer-to-peer, stored-video streaming service over the Internet, such as on-line DVD rentals. P2P allows a group of dynamically organized users to cooperatively support content discovery and distribution services without needing to employ a central server. P2P has the potential to overcome the scalability issue associated with client-server based video distribution networks; however, it brings a new set of challenges. This research addresses the following five technical challenges associated with the distribution of streaming video over the P2P network: 1) allow users with limited transmit bandwidth capacity to become contributing sources, 2) support the advertisement and discovery of time-changing and time-bounded video frame availability, 3) Minimize the impact of distribution source losses during video playback, 4) incorporate user mobility information in the selection of distribution sources, and 5) design a streaming network architecture that enables above functionalities.To meet the above requirements, we propose a video distribution network model based on a hybrid architecture between client-server and P2P. In this model, a video is divided into a sequence of small segments and each user executes a scheduling algorithm to determine the order, the timing, and the rate of segment retrievals from other users. The model also employs an advertisement and discovery scheme which incorporates parameters of the scheduling algorithm to allow users to share their life-time of video segment availability information in one advertisement and one query. An accompanying QoS scheme allows reduction in the number of video playback interruptions while one or more distribution sources depart from the service prematurely.The simulation study shows that the proposed model and associated schemes greatly alleviate the bandwidth requirement of the video distribution server, especially when the number of participating users grows large. As much as 90% of load reduction was observed in some experiments when compared to a traditional client-server based video distribution service. A significant reduction is also observed in the number of video presentation interruptions when the proposed QoS scheme is incorporated in the distribution process while certain percentages of distribution sources depart from the service unexpectedly

    The state of peer-to-peer network simulators

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    Networking research often relies on simulation in order to test and evaluate new ideas. An important requirement of this process is that results must be reproducible so that other researchers can replicate, validate and extend existing work. We look at the landscape of simulators for research in peer-to-peer (P2P) networks by conducting a survey of a combined total of over 280 papers from before and after 2007 (the year of the last survey in this area), and comment on the large quantity of research using bespoke, closed-source simulators. We propose a set of criteria that P2P simulators should meet, and poll the P2P research community for their agreement. We aim to drive the community towards performing their experiments on simulators that allow for others to validate their results

    Supporting Non-Linear and Non-Continuous Media Access in Peer-to-Peer Multimedia Systems

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    Ph.DDOCTOR OF PHILOSOPH

    Content Distribution in P2P Systems

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    The report provides a literature review of the state-of-the-art for content distribution. The report's contributions are of threefold. First, it gives more insight into traditional Content Distribution Networks (CDN), their requirements and open issues. Second, it discusses Peer-to-Peer (P2P) systems as a cheap and scalable alternative for CDN and extracts their design challenges. Finally, it evaluates the existing P2P systems dedicated for content distribution according to the identied requirements and challenges

    Scalable service for flexible access to personal content

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    Multimedia Content Distribution Management Using a Distributed Topology

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    Advertising plays an important role in order for many companies to promote their products and services. It can be expensive to place advertisements with no guarantees that the message will reach the intended persons. In this field, targeted advertising is the mainstream strategy to captivate the potential consumer. People are used to see advertisements everywhere they go in many different forms. One of those is the use of screen displays that are believed to make the ads more engaging. However, using digital screens to advertise may lead to some issues, like down times or unwanted error messages from the device that controls the screens. This can cause a bad experience for both the target audience and the advertiser. This thesis was developed within the scope of a project called Vixtape. It’s a platform with the goal of turning any public screen into an ads displaying device and in the process reward the screen owner by exposing ads to the target audience. It also has the mission of giving the end user a optimal technological experience, no flaws and highly efficient. All these characteristics are accomplished by the use of a new open source technology called Interplanetary File System (IPFS), that allow devices to share content between them in a Peer-to-Peer (P2P) topology. This content distribution method saves Internet bandwidth to the end user (i.e., the Vixtape service client) and also enables the devices to work offline in case their Internet connection drops. This will greatly reduce the common problems seen with ads screen, thus giving a better experience to both the audience and the end user. By the end of this document one can see that, adding a distributed topology to the Vixtape platform increased the Internet usage efficiency of the ads devices by always having up-to-date content available. This avoids that a device unnecessarily requests content from any of the other devices that had previously requested it. Additionally, a strategy to target a given audience was employed in order to choose the right ads to play. This further increases the maximum potential consumers the advertisements are shown to

    Smart PIN: performance and cost-oriented context-aware personal information network

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    The next generation of networks will involve interconnection of heterogeneous individual networks such as WPAN, WLAN, WMAN and Cellular network, adopting the IP as common infrastructural protocol and providing virtually always-connected network. Furthermore, there are many devices which enable easy acquisition and storage of information as pictures, movies, emails, etc. Therefore, the information overload and divergent content’s characteristics make it difficult for users to handle their data in manual way. Consequently, there is a need for personalised automatic services which would enable data exchange across heterogeneous network and devices. To support these personalised services, user centric approaches for data delivery across the heterogeneous network are also required. In this context, this thesis proposes Smart PIN - a novel performance and cost-oriented context-aware Personal Information Network. Smart PIN's architecture is detailed including its network, service and management components. Within the service component, two novel schemes for efficient delivery of context and content data are proposed: Multimedia Data Replication Scheme (MDRS) and Quality-oriented Algorithm for Multiple-source Multimedia Delivery (QAMMD). MDRS supports efficient data accessibility among distributed devices using data replication which is based on a utility function and a minimum data set. QAMMD employs a buffer underflow avoidance scheme for streaming, which achieves high multimedia quality without content adaptation to network conditions. Simulation models for MDRS and QAMMD were built which are based on various heterogeneous network scenarios. Additionally a multiple-source streaming based on QAMMS was implemented as a prototype and tested in an emulated network environment. Comparative tests show that MDRS and QAMMD perform significantly better than other approaches

    Location-aware mechanism for efficient video delivery over wireless mesh networks

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    Due to their flexibility, ease of use, low-cost and fast deployment, wireless Mesh Networks have been widely accepted as an alternative to wired network for last-mile connectivity. When used in conjunction with Peer-to-Peer data transfer solutions, many innovative applications and services such as distributed storage, resource sharing, live TV broadcasting or Video on Demand can be supported without any centralized administration. However, in order to achieve a good quality of service in such variable, error-prone and resource-constrained wireless multi-hop environments, it is important that the associated Peer-to-Peer overlay is not only aware of the availability, but also of the location and available path link quality of its peers and services. This thesis proposes a wireless location-aware Chord-based overlay mechanism for Wireless Mesh Networks (WILCO) based on a novel geographical multi-level ID mapping and an improved finger table. The proposed scheme exploits the location information of mesh routers to decrease the number of hops the overlay messages traverse in the physical topology. Analytical and simulation results demonstrate that in comparison to the original Chord, WILCO has significant benefits: it reduces the number of lookup messages, has symmetric lookup on keys in both the forward and backward direction of the Chord ring and achieves a stretch factor of O(1). On top of this location-aware overlay, a WILCO-based novel video segment seeking algorithm is proposed to make use of the multi-level WILCO ID location-awareness to locate and retrieve requested video segments from the nearest peer in order to improve video quality. An enhanced version of WILCO segment seeking algorithm (WILCO+) is proposed to mitigate the sometimes suboptimal selection of the WILCO video segment seeking algorithm by extracting coordinates from WILCO ID to enable location-awareness. Analytical and simulation results illustrate that the proposed scheme outperforms the existing state-of-the-art solutions in terms of PSNR and packet loss with different background traffic loads. While hop count is frequently strongly correlated to Quality of Service, the link quality of the underlying network will also have a strong influence on content retrieval quality. As a result, a Cross-layer Wireless Link Quality-aware Overlay peer selection mechanism (WLO) is proposed. The proposed cross-layer mechanism uses a Multiplication Selector Metric (MSM) to select the best overlay peer. The proposed MSM overcomes the two issues facing the traditional summation-based metric, namely, the difficulty of bottleneck link identification and the influence of hop count on behavior. Simulation results show that WLO outperforms the existing state-of-the-art solutions in terms of video quality at different background loads and levels of topology incompleteness. Real life emulation-based tests and subjective video quality assessments are also performed to show that the simulation results are closely matched by the real-life emulation-based results and to illustrate the significant impact of overlay peer selection on the user perceived video quality
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