Diverse Multimedia Applications Research Articles

Prediction-Based Channel Selection Prediction in Mobile Cognitive Radio Network

The emerging 5G wireless communications enabled diverse multimedia applications and smart devices in the network. It promises very high mobile traffic data rates, quality of service as in very low latency and improvement in user’s perceived quality of experience compared to current 4G wireless network. This encourages the increasing demand of significant bandwidth which results a significant urge of efficient spectrum utilization. In this paper, modelling, performance analysis and optimization of future channel selection for cognitive radio network by jointly exploiting both CR mobility and primary user activity to provide efficient spectrum access is studied. The modelling and prediction method is implemented by using Hidden Markov Model algorithm. The movement of CR in wireless network yields location-varying spectrum opportunities. The current approaches in most literatures which only depend on reactive selection spectrum opportunities result of inefficient channel usages. Moreover, conventional random selection method tends to observe a higher handoff and operation delays in network performance. This inefficiency can cause continuous transmission interruptions leading to the degradation of advance wireless services. This work goal is to improve the performance of CR in terms number of handoffs and operation delays. We perform simulation on our prediction strategy with a commonly used random sensing method with and without location. Through simulations, it is shown that the proposed prediction and learning strategy can obtain significant improvements in number of handoffs and operation delays performance parameters. It is also shown that future CR location is beneficial in increasing mobile CR performance. This study also shows that the number of primary user in the network and the PU protection range affect the performance of mobile CR channel selection for all methods.

Towards the design of a consistent image contrast enhancement evaluation measure

Contrast Enhancement Evaluation (CEE) is a very challenging problem. In this work, we provide a detailed performance analysis of CEE measures. The study was conducted on our newly developed database dedicated to psychophysical Contrast Enhancement (CE) quality evaluation. The database contains 30 original images and 180 enhanced images obtained using six different CE methods as a representative set of the most common approaches used in the literature. The CE methods were subjectively evaluated and ranked by 23 observers using a Pairwise Comparison (PC) protocol. The correlation analysis between the subjective preferences and objective evaluations of the enhanced images show that most of the existing CEE metrics are not well consistent with the human judgment of quality. We also present in this paper a thorough discussion on the available CEE metrics, their strengths, their weaknesses, and their inter-correlation. In addition to the individual metrics, we show that by fusing different metrics together, a significant increase in correlation performance can be achieved. This study reveals that there is a clear need to develop more robust CEE measures which are perceptually motivated and correlated well with the quality of enhancement a given image is subjected to. The new database introduced in this paper is expected to contribute substantially promoting such research area, which is of primary importance to diverse multimedia applications.

Quality of service aware cloud resource provisioning for social multimedia services and applications

The increasing number of next-generation multimedia services and social media applications in cloud computing put additional challenges in efficient resource provisioning that targets to minimize under or over utilization of resources as well as to increase user satisfaction. Most of the works in the literature focused either on resource estimation and scheduling approaches or energy consumption for executing social media data processing applications. However, they do not consider energy consumption cost for communication devices and network appliances and schedule Virtual Machines (VMs) based on centralized job placement approach. In this paper, we develop a Quality of Service (QoS) aware cloud resource management system that decreases energy consumption and increases resource utilization by diverse multimedia social applications. In order to minimize the VM creation time we allow recycling of VM resources for user request with similar resource requirements. We have developed two distributed and localized resource management algorithms based on energy conservation, and requirements and availability of resources. The results of simulation experiments depict that the resource scheduling system greatly reduces the amount of energy consumption while maintaining the QoS of social multimedia applications.

A dynamic programing solution for QoS routing in wireless ad hoc network with energy constraints

In mobile ad hoc networks (MANETs), it is essential to provide quality of service (QoS) guarantee for diverse multimedia applications. Most researches focus on the QoS metrics but neglect the energy constraints of MANET itself which is a fairly important problem. In this paper we aimed to solve the battery limitation and bandwidth constraints in MANETs using dynamic programming method. We first construct a QoS routing model based on dynamic programming and then make a detailed description of the algorithm. Simulations are conducted to evaluate the performance of the proposed algorithm.

QoS Provisioning with New Effective Bandwidth/Buffer Calculation Scheme in Wireless IP Networks

The huge commercial success of mobile telephony, the phenomenal growth of Internet users, the popularity of IP-based multimedia applications are the major driving forces behind third-generation (3G), ongoing Byond 3G (B3G), and forth-genertion (4G) evolution. 3G brought wired applications, both data and multimedia, into wireless environments. It operates on IP-based infrastructures to provide wider service access capability. To support and satisfy QoS (Quality of Service) of diverse IP-based multimedia applications, traffic management, such as Connection Admission Control (CAC) and resource allocation, becomes essential. CAC and resource allocation are computationally complex when combined with QoS guarantee for traffic with different characteristics. However, CAC and resource allocation are real-time traffic control procedures. Hence, processing load should be minimized to reduce delay. At the same time, network resources should be utilized efficiently to accommodate more users. However, reducing processing load and obtaining high resource utilization efficiency has been considered to be contradictory matter. In addition, CAC and resource allocation schemes which consider multiple QoS criteria --- loss and delay --- simultaneously have not been adequately studied. Simultaneous QoS consideration is important to satisfy stringent and diverse QoS requirements of multimedia traffic. In this paper, we propose a nobel effective bandwidth/buffer calculation method based on a virtual channel/buffer analysis scheme. We show that our method can achieve high resource utilization efficiency with reduced processing load. Moreover, we show that our scheme allows for simultaneous consideration of multiple QoS criteria, loss and delay.

Multimedia friendly home wireless LANs

Home wireless local area networks (LANs) will carry diverse multimedia applications such as data, video, voice, and time sensitive control information. To enable quality delivery of such applications, these networks should incorporate an efficient quality of service (QoS) support mechanism. However, existing home wireless LANs do not provide support for multimedia applications. In this paper, we introduce our software based solution that provides QoS support for voice, video and data while using existing wireless home networks. The experimental results we have obtained provide evidence that our solution provides QoS support for multimedia applications.

A programmable transport architecture with QoS guarantees

The emergence of distributed multimedia applications exhibiting significantly more stringent quality of service requirements than conventional data-oriented applications calls for new transport protocols with different characteristics to coexist and be integrated within single applications. The different delivery requirements posed by these diverse multimedia applications often imply the need for highly customized protocol implementations. Hence, application developers are faced with the threat of code obsolescence caused by the development of even newer delivery techniques. We present an object-oriented transport architecture that allows for dynamically binding a variety of protocol stacks on a per-call basis. By binding protocol stacks together, the special needs of the application can be met without the need to rewrite the code. This differs significantly from the traditional transport architecture which assumes preinstalled transport protocol stacks that cannot be customized. To illustrate some of the advantages provided by the architecture, we describe the transport component of the first reference implementation of the 150 MPEG-4 Delivery Multimedia Integration Framework and demonstrate how quickly it was implemented in our framework.

Achieving multimedia synchronization between live video and live audio streams using QoS controls

Recent developments of high-speed networking technologies and transmission media make it feasible to have diverse multimedia applications over integrated service networks. In order to guarantee Quality Of Presentation (QOP) to users, it is necessary to negotiate QOP parameters at the networking connection setup time, and it is also necessary to maintain service qualities during the time of presenting multimedia information. In this paper, we propose using a multimedia synchronization method for supporting smooth presentation of live multimedia information in ATM-based networking environments. The mathematic relationships among the buffer size, the maximum jitter, the presentation and transmission rates, the maximum intra- and inter-media asynchrony anomalies, etc., are presented in detail. We perform a bounded buffer allocation scheme, and forward synchronization policies for synchronizing live video and live audio streams. Since the transmission rate of live media cannot be adjusted, we perform the forward synchronization policies to overcome the asynchrony anomalies. The presentation processes at the receiver site monitor the presentation asynchrony anomalies. Once the anomalies of presentation are detected, the forward re-synchronization policy is triggered to eliminate the asynchrony anomalies. Neither a global clock nor a feedback mechanism is needed using our method.

ADAPTIVE: A dynamically assembled protocol transformation, integration and evaluation environment

AbstractComputer communication systems must undergo significant changes to keep pace with the increasingly demanding and diverse multimedia applications that will run on the next generation of high‐performance networks. To facilitate these changes, we are developing A Dynamically Assembled Protocol Transformation, Integration and evaluation Environment (ADAPTIVE). ADAPTIVE provides an integrated environment for developing and experimenting with flexible transport system architectures that support lightweight and adaptive communication protocols for diverse multimedia applications running on high‐performance networks. Our approach employs a collection of reusable ‘building‐block’ protocol mechanisms that may be composed together automatically based upon functional specifications. The resulting protocols execute in parallel on several target platforms including shared‐memory and message‐passing multiprocessors. ADAPTIVE provides a framework for (1) determining the functionality of customized lightweight protocol configurations that efficiently support multimedia applications and (2) mapping this functionality onto efficient parallel process architectures.