53 research outputs found

    Multimedia streaming adaptation IMS-networks

    Get PDF
    Introduction Multimedia services such as video, gaming and music marked the close of the last century and have become inextricably linked with our lives in the current century. The success and popularity of these services was fuelled by the explosive expansion of the Internet and the furious penetration of broadband networks. In particular, the use of multimedia streaming services on portable devices has been popular whenever both the content and the perceived delivery quality have met the expectations of end users. This chapter of the book does not address content aspects of multimedia streaming services. Such matters are left to media gurus and other researchers. Rather, this chapter focuses on the delivery quality of multimedia streaming services. Particular attention is paid to quality adaptation techniques intended to improve end users' experience of such services. Our scope includes heterogeneous networks and devices. The solutions presented are applicable to the telecommunications industry

    Real-time resource availability signaling in IP multimedia subsystem networks

    Get PDF
    IP Multimedia Subsystem (IMS) allows the use of unlicensed, non-dedicated and nondeterministic access networks for delivering IP multimedia services. Providing end-to-end Quality-of-Service (QoS) for resource demanding real-time services (e.g. real-time multimedia) over such networks is a challenging task due to varying resource availability of the network and the end-devicei during a single sessionii. A common solution to this problem is adapting service quality and type according to availability of system resources, which requires end-to-end monitoring and signaling of resource availability during a single session. This paper presents an extension of the IMS architecture for real-time resource availability monitoring and signaling. The novelty of the proposed extension is twofold. It takes into account uncontrolled access networks with no resource reservation on the one hand, and end devices on the other. Two system architecture components are introduced for monitoring and signaling of the real-time resource availability in both networks (e.g. bandwidth, buffer space), and end-devices (e.g. battery, CPU, memory, storage), namely a Resource Manager (RM) and a Resource Availability Server (RAS). Our solution does not require any modifications of the IMS architecture and can be implemented as a plug-in

    Complexity scalable motion estimation control for H.264/AVC

    Get PDF
    Guaranteeing real-time performance for video encoding on platforms with limited resources is becoming increasingly important for consumer electronics applications. In this paper, an extension of an H.264/AVC encoder with complexity scalable motion estimation (ME) control is presented. An upper bound on the complexity of encoding a single frame is achieved by restricting Sum of Absolute Differences (SAD) computations performed during ME and trading complexity allocation per frame for output quality. Allocation based on residual, i.e. SAD distortion of the final ME match before quantization, of the co-located macroblock in the previous frame outperforms other approaches in the literature in video quality

    System architecture for road lighting

    Get PDF
    Traditional road lighting systems consume a large amount of energy. When the ambient light falls under a certain threshold, all the luminaries are turned at full-power without considering user perception and interaction. The feeling of safety experienced by users and user-lighting system interaction via consumer electronics (CE) devices should be investigated. For this study, we establish a software-controlled testbed that allows changing the brightness level of each street luminary remotely. In this paper, we describe the system architecture of this testbed deployed on a street along with the future work directions

    Real-time resource availability signaling in IP multimedia subsystem networks

    Get PDF
    ABSTRACT IP Multimedia Subsystem (IMS

    Power-managed smart lighting using a semantic interoperability architecture

    Get PDF
    Abstract-This paper presents a power-managed smart lighting system that allows collaboration of lighting consumer electronics (CE) devices and corresponding system architectures provided by different CE suppliers. In the example scenario, the rooms of a building are categorized as low and high priority, each category utilizing a different system architecture. The rooms collaborate through a semantic interoperability platform. The overall smart lighting system conforms to a power quota regime and maintains a target power consumption level by automatically adjusting lights in the building

    Multiple objective optimization for video streaming

    No full text

    Multimedia adaptation with SIP resource availability signalling in IMS-networks

    No full text
    Unlicensed, nondedicated and nondeterministic computer access networks are included in IP multimedia subsystem (IMS) in addition to the operator core network, which arises new end-to-end quality-of-service (QoS) issues for multimedia streaming. The resource availability of the network and the end-devices change drastically during a single multimedia session, which may cause a significant degradation in the overall user experience. In this paper, a multimedia content and quality adaptation framework depending on resource availability signalling over session initiation protocol (SIP) is proposed as a solution to this problem. Availability of network resources (e.g. bandwidth, buffer space) and end-device resources (e.g. battery, CPU, memory, storage) during a session is monitored and signalled over the network in real-time by the resource managers residing at both ends of the session. This framework is compliant with the IMS standard and is implemented as a plug-in

    Client intelligence for adaptive streaming solutions

    No full text
    In state-of-the-art adaptive streaming solutions, to cope with varying network conditions, the client side can switch between several video copies encoded at different bit-rates during streaming. Each video copy is divided into chunks of equal duration. To achieve continuous video playback, each chunk needs to arrive at the client before its playback deadline. The perceptual quality of a chunk increases with the chunk size in bits, whereas bigger chunks require more transmission time and, as a result, have a higher risk of missing transmission deadline. Therefore, there is a trade-off between the overall video quality and continuous playback, which can be optimized by proper selection of the next chunk from the encoded versions. This paper proposes a method to compute a set of optimal client strategies for this purpose

    A comparison of predictive algorithms for failure prevention in smart environment applications

    No full text
    The functional correctness and the performance of smart environment applications can be hampered by faults. Fault tolerance solutions aim to achieve graceful performance degradation in the presence of faults, ideally without leading to application failures. This is a reactive approach and, by itself, gives little flexibility and time for preventing potential failures. We argue that the key step in achieving high dependability is to predict faults before they occur. We propose a proactive fault prevention framework, which predicts potential low-level hardware, software and network faults and tries to prevent them via dynamic adaptation. Many statistical fault prediction algorithms have been proposed in the literature. In this paper, we evaluate and compare the performances of two fault prediction models, namely, multiple linear regression, and artificial neural networks by using them to predict the remaining useful life of a battery-powered wireless sensor network node. The results show that the proposed framework will provide better control over performance degradation of smart environment applications, and will increase reliability and availability, and reduce manual user interventions
    • …
    corecore