81 research outputs found

    Overview of Hybrid MANET-DTN Networking and its Potential for Emergency Response Operations

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    Communication networks for emergency response operations have to operate in harsh environments. As fixed infrastructures may be unavailable (e.g., they are destroyed or overloaded), mobile ad-hoc networks (MANETs) are a promising solution to establish communication for emergency response operations. However, networks for emergency responses may provide diverse connectivity characteristics which imposes some challenges, especially on routing. Routing protocols need to take transmission errors, node failures and even the partitioning of the network into account. Thus, there is a need for routing algorithms that provide mechanisms from Delay or Disruption Tolerant Networking (DTN) in order to cope with network disruptions but at the same time are as efficient as MANET routing schemes in order to preserve network resources. This paper reviews several hybrid MANET-DTN routing schemes that can be found in the literature. Additionally, the paper evaluates a realistic emergency response scenario and shows that MANET-DTN routing schemes have the potential to improve network performance as the resulting network is diverse in terms of connectivity. In particular, the network provides well-connected regions whereas other parts are only intermittently connected

    A Multimedia Delivery System for Delay-/Disruption-Tolerant Networks

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    Abstract-Multimedia delivery systems and protocols usually assume end-to-end connections and low delivery delays between multimedia sources and consumers. However, neither of these two properties can always be achieved in hastily formed networks for emergency response operations. In particular, disruptions may break end-to-end connections, which makes it impossible to deliver multimedia content instantly. This work presents a multimedia delivery system that can operate in disrupted networks and hence may help improve the situational awareness in emergency response operations. The multimedia delivery system is based on HTTP adaptive streaming (HAS) and uses a modified version of HTTP which is able to deliver data in partitioned networks. The multimedia delivery system is evaluated in a realistic emergency response scenario

    A Framework for Personalized Utility-Aware IP-Based Multimedia Consumption

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    Providing transparent and augmented use of multimedia con-tent across a wide range of networks and devices is still a challenging task within the multimedia research community. Multimedia adaptation was figured out as a core concept to overcome this issue. Most multimedia adaptation engines for providing Universal Multimedia Access (UMA) scale the content under consideration of terminal capabilities and re-source constraints but do not really consider individual user preferences. This paper introduces an adaptive multimedia framework which offers the user a personalized content vari-ation for satisfying his/her individual utility preferences. 1

    Improving the Quality of Multimedia Experience through Sensory Effects. In:

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    ABSTRACT In previous and related work sensor

    Evaluating the networking performance of Linux-based home router platforms for multimedia services

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    ABSTRACT Wireless router platforms based on the Linux operating system are becoming popular in consumers' home networks. The transmission of multimedia data or their use as mediaaware network elements imposes high traffic and computational loads on these devices. Thus, it is interesting to evaluate the networking and processing capabilities of such home router platforms in order to assess their usefulness for improved multimedia services such as in-network H.264/SVC video stream adaptation. This paper presents a performance evaluation of three home router platforms representative for low-end, mid-range, and high-end devices. The scope of the evaluation is the performance of the Linux networking stack on these routers; results for both application-layer (TCP and UDP) transmission and kernel-level (UDP) traffic routing are given. The results show that both TCP and UDP throughputs are significantly below (less than half of) the outgoing (wired) links' nominal capacities and depend very much on the sizes of the transmitted data blocks. This clearly indicates that the networking performance is limited by the platforms' processing capabilities and the lack of mechanisms that offload networking tasks from the CPUs. This behaviour cannot be observed on today's PC systems and has to be considered when deploying multimedia services on these network devices. Furthermore, a detailed analysis of the Linux networking stack reveals that the performance is heavily impacted by the netfilter code, even when no packet filtering or network address translation is being performed. Considerable performance gains can be achieved when this netfilter code is bypassed

    Increasing the User Experience of Multimedia Presentations with Sensory Effects",

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    ABSTRACT The term Universal Multimedia Experience (UME) has gained momentum and is well recognized within the research community. As this approach puts the user into the center stage, additional complexity is added to the overall quality assessment problem which calls for a scientific framework to capture, measure, quantify, judge, and INTRODUCTION The Universal Multimedia Experience (UME) is nowadays well known within the research community and has been derived from Universal Multimedia Access (UMA) The remainder of this paper is organized as follows. Section 2 describes the Sensory Effect Media Player (SEMP) which has been developed in order to conduct the subjective tests. Section 3 provides the actual test environment including the extended test procedure and the evaluation results. Conclusions and future work items are presented in Section 4. SENSORY EFFECT MEDIA PLAYER The Sensory Effect Media Player (SEMP) is a DirectShowbased media player with support for the Sensory Effect Description Language (SEDL) as defined i

    Scalable Video Coding Guidelines and Performance Evaluations for Adaptive Media Delivery of High Definition Content

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    International audienceScalability within media coding allows for content adaptation towards heterogeneous user contexts and enables in-network adaptation. However, there is no straightforward solution how to encode the content in a scalable way while maximizing rate-distortion performance. In this paper we provide encoding guidelines for scalable video coding based on a survey of media streaming industry solutions and a comprehensive performance evaluation using four state of the art scalable video codecs with a focus on high-definition content (1080p)
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