Cross-Layer Optimization for Video-streaming Transmission with QoS over Ad Hoc Networks: A Holistic Approach

In this paper we present ViStA-XL, a Cross-Layer (XL) design aiming to optimize the overall performance of videostreaming services over Mobile Ad Hoc Networks (MANETs). The idea relies on applying optimization strategies to different network layers in a holistic way. In ViStA-XL, a real-time Optimizer (XLO) periodically gathers information of the state of node and network from different layers of the stack of protocols, takes optimization decisions, and then modifies some parameters of the protocols accordingly. In addition, our proposal exploits path diversity through MM-DSR (Multipath MultimediaDynamic Source Routing) protocol as a means to reinforce the Quality of Service (QoS) provision to multi-layer encoded videostreaming applications, by protecting the most important video information packets, balancing the load and decreasing the endto-end delay. To show the advantages of our approach, we have developed and tested an algorithm based on ViStA-XL. Simulation results show that our proposed network design can improve the performance of video-streaming transmissions over MANETs in spite of frequent changes in network and node operating conditions

Self-configured multipath routing using path lifetime for video-streaming services over Ad Hoc networks

The increasing spread of mobile nodes along with the technical advances in multi-hop MANETs (Mobile Ad hoc NETworks) make this kind of networks an important type of access network of next generation. The demand of multimedia services from these networks is expected to significantly grow in the next years. Multimedia services, though, require the provision of Quality of Service (QoS). Nevertheless, the highly dynamic nature of MANETs, the energy constraints, the lack on centralized infrastructure and the variable link capacity, makes the QoS provision over MANETs a matter that challenges attention. These features make self-configuration and system adaptation questions of major importance when developing a QoS-aware framework. To tackle this issue, we have designed a-MMDSR (adaptive-Multipath Multimedia Dynamic Source Routing), a multipath routing protocol able to self-configure dynamically depending on the state of the network. The approach includes cross-layer techniques especially designed to improve the end-to-end performance of video-streaming services over IEEE 802.11e Ad Hoc networks. Besides, a straightforward analytical model to estimate the path error probability is presented. This model is used by the routing scheme to estimate the lifetime of the paths. In this way, proper proactive decisions can be made before the paths get broken. The model simplicity is appropriate for low capacity wireless devices. Simulation results validate the proposal and show the improvement on standard DSR (Dynamic Source Routing) and on a previous static version

Dynamic cross-layer framework to provide QoS for video streaming services over ad hoc networks

In recent years the growing proliferation of small wireless devices able to maintain wireless communications using IEEE 802.11 technologies has enabled the deployment of ANETs (Mobile Ad Hoc Networks). This fact as stimulated the demand of multimedia services over this type of networks, such as video-streaming services. Providing QoS in this environment is a challenging task due to the inherent dynamic characteristics of these networks. In this paper we propose a-MMDSR (adaptable-Multipath Multimedia ynamic Source Routing), a dynamic framework for video streaming services which improves the user perceived quality. We have erfected our previous approach s-MMDSR (static- MMDSR), a multipath routing protocol based on DSR which works multaneously with a cross-layer algorithm. hrough simulations, we demonstrate that the performance of our proposal framework outperforms DSR and s-MMDSR.Postprint (published version

Dynamic cross-layer framework to provide QoS for video streaming services over ad hoc networks

In recent years the growing proliferation of small wireless devices able to maintain wireless communications using IEEE 802.11 technologies has enabled the deployment of ANETs (Mobile Ad Hoc Networks). This fact as stimulated the demand of multimedia services over this type of networks, such as video-streaming services. Providing QoS in this environment is a challenging task due to the inherent dynamic characteristics of these networks. In this paper we propose a-MMDSR (adaptable-Multipath Multimedia ynamic Source Routing), a dynamic framework for video streaming services which improves the user perceived quality. We have erfected our previous approach s-MMDSR (static- MMDSR), a multipath routing protocol based on DSR which works multaneously with a cross-layer algorithm. hrough simulations, we demonstrate that the performance of our proposal framework outperforms DSR and s-MMDSR

Dynamic cross-layer framework to provide QoS for video streaming services over ad hoc networks

In recent years the growing proliferation of small wireless devices able to maintain wireless communications using IEEE 802.11 technologies has enabled the deployment of ANETs (Mobile Ad Hoc Networks). This fact as stimulated the demand of multimedia services over this type of networks, such as video-streaming services. Providing QoS in this environment is a challenging task due to the inherent dynamic characteristics of these networks. In this paper we propose a-MMDSR (adaptable-Multipath Multimedia ynamic Source Routing), a dynamic framework for video streaming services which improves the user perceived quality. We have erfected our previous approach s-MMDSR (static- MMDSR), a multipath routing protocol based on DSR which works multaneously with a cross-layer algorithm. hrough simulations, we demonstrate that the performance of our proposal framework outperforms DSR and s-MMDSR

Cavitation erosion in a corrosive environment

SIGLEAvailable from British Library Document Supply Centre- DSC:D72522/87 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

A game-theoretic multipath routing for video-streaming services over mobile Ad Hoc networks

The number of portable devices capable of maintaining wireless communications has increased considerably in the last decade. Such mobile nodes may form a spontaneous self-configured network connected by wireless links to constitute a Mobile Ad Hoc Network (MANET). As the number of mobile end users grows the demand of multimedia services, such as video-streaming, in such networks is envisioned to increase as well. One of the most appropriate video coding technique for MANETs is layered MPEG-2 VBR, which used with a proper multipath routing scheme improves the distribution of video streams. In this article we introduce a proposal called g-MMDSR (game theoretic-Multipath Multimedia Dynamic Source Routing), a cross-layer multipath routing protocol which includes a game theoretic approach to achieve a dynamic selection of the forwarding paths. The proposal seeks to improve the own benefits of the users whilst using the common scarce resources efficiently. It takes into account the importance of the video frames in the decoding process, which outperforms the quality of the received video. Our scheme has proved to enhance the performance of the framework and the experience of the end users. Simulations have been carried out to show the benefits of our proposal under different situations where high interfering traffic and mobility of the nodes are present.Peer ReviewedPreprin

A game-theoretic multipath routing for video-streaming services over mobile Ad Hoc networks

The number of portable devices capable of maintaining wireless communications has increased considerably in the last decade. Such mobile nodes may form a spontaneous self-configured network connected by wireless links to constitute a Mobile Ad Hoc Network (MANET). As the number of mobile end users grows the demand of multimedia services, such as video-streaming, in such networks is envisioned to increase as well. One of the most appropriate video coding technique for MANETs is layered MPEG-2 VBR, which used with a proper multipath routing scheme improves the distribution of video streams. In this article we introduce a proposal called g-MMDSR (game theoretic-Multipath Multimedia Dynamic Source Routing), a cross-layer multipath routing protocol which includes a game theoretic approach to achieve a dynamic selection of the forwarding paths. The proposal seeks to improve the own benefits of the users whilst using the common scarce resources efficiently. It takes into account the importance of the video frames in the decoding process, which outperforms the quality of the received video. Our scheme has proved to enhance the performance of the framework and the experience of the end users. Simulations have been carried out to show the benefits of our proposal under different situations where high interfering traffic and mobility of the nodes are present.Peer Reviewe

Dynamic framework with adaptive contention window and multipath routing for video-streaming services over mobile ad hoc networks

The number of portable electronic devices capable of maintaining wireless communications increases day by day. Such mobile nodes may easily self-configure to form a Mobile Ad Hoc Network (MANET) without the help of any established infrastructure. As the number of mobile devices grows, the demand of multimedia services such as video-streaming from these networks is foreseen to increase as well. This paper presents a proposal which seeks to improve the experience of the end users in such environment. The proposal is called dCW-MMDSR (dynamic Contention Window-Multipath Multimedia Dynamic Source Routing), a cross-layer multipath routing protocol which includes techniques to achieve a dynamic assignment of the Contention Window of the IEEE 802.11e MAC level. In addition, it includes multipath routing suitable for layered coded video to improve the performance of the service. The operation is simple and suitable for low capacity wireless devices. Simulations show the benefits under different scenarios