Generation Multimedia Applications Research Articles

New context of compression problem and approach to solution: a survey of the literature

The new generation multimedia applications such as ultra-high definition TV, 3D video and cloud storage keeps the compression research relevant even post to the advent of the state-of-art standard HEVC (High Efficiency Video Coding) codec. The continued studies on human visual system suggest that a perceptually acceptable reconstruction with reduced bandwidth requirements may be more acceptable and commercially viable solution rather than a bit accurate reconstruction for a variety of video and graphics applications. One way to achieve compression beyond that achieved by the advanced codec like HEVC is to sample the input data at a lower rate than the Nyquist rate, exploit the sparsity and perceptual redundancy in the content using advanced signal processing and computer vision tools and represents it using a spatio-temporal model. This paper contains an exhaustive review of the new context of video compression methods along with their limitations and open issues.

Expanding LTE network spectrum with cognitive radios: From concept to implementation

Wireless data traffic is growing extraordinarily, with new wireless devices such as smartphones and bandwidth-demanding wireless applications such as video streaming becoming increasingly popular and widely adopted. Correspondingly, we have also witnessed the phenomenal wireless technology evolutions to support higher system capacities from generation to generation. Long Term Evolution has been developed as a 4G wireless technology that can support next generation multimedia applications with high capacity and high mobility needs. However, the peak data rate from 3G UMTS to 4G LTE-Advanced only increases 55 percent annually, while global mobile traffic has increased 66 times with an annual growth rate of 131 percent between 2008 and 2013. Clearly, there is a huge gap between the growth rate of the new air interface and the growth rate of customers¿ needs. A promising way to alleviate the contention between the actual traffic demands and the actual system capacity growth is to exploit more available spectrum resources. Recently, cognitive radio technology has been under extensive research and study. It aims to provide abundant new spectrum opportunities by exploiting underutilized or unutilized spectrum opportunistically. In this article, we discuss the technical solutions to expand LTE spectrum with CR technology (LTE-CR), and survey the advances in LTE-CR from both research and implementation aspects. We present detailed key technologies that enable LTE-CR in the TV white space (TVWS), and related standards and regulation progresses. To demonstrate the feasibility of deploying LTECR in TVWS, we have conducted extensive system-level simulations and also developed a LTE-CR prototype. Both simulation and laboratory testing results show that applying LTECR in TVWS can achieve satisfactory performance.

Special issue on advanced intelligent multimedia applications for next generation environments

Next generation (NG) environments have recently raised relevant interests in both the academic and industrial research communities as one of the most promising application fields for intelligent computing services. In fact, the NG application domain poses unique challenges such as various services to enable working from home, remote education, remote diagnosis, virtual shopping, network gaming, and portal & high quality VOD with no limitations on space and time, and so on. Specially, advanced intelligent multimedia applications for NG have been coming as a new paradigm. This special issue aims to address the advanced intelligent multimedia applications for NG. Submissions to this special issue come from an open call for papers as well as from selected papers presented at the 2008 International Symposium on Ubiquitous Multimedia Computing (UMC-08) held at Hobart, Australia, from 13 to 15 October, 2008. Accordingly, a number of papers included in this special issue concentrate on advanced intelligent multimedia applications including topics like smart homes, intelligent multimedia systems, human communication interaction, context-awareness, advanced image processing, security issues that are associated with next generation multimedia applications. Kim et al. has proposed a shape-based index matching scheme for camera view invariant 3-D object retrieval. Especially, in order to remove redundant camera views to be indexed, authors investigate the symmetrical shape pattern of objects and propose two camera view skimming methods, which are mirror shape pairing and camera view pruning. Through Multimed Tools Appl (2010) 47:1–5 DOI 10.1007/s11042-009-0427-0

The IP multimedia domain: service architecture for the delivery of voice, data, and next generation multimedia applications

The IP Multimedia Subsystem (IMS) is defined by the 3rd Generation Partnership Project (3GPP) as a new core network domain. IMS provides a service control platform that allows creation of new multimedia and multi-session applications utilizing wireless and wireline transport capabilities. In this paper we will cover the concepts and standards defining IMS and review the network architecture from a mobile perspective. We will see how IMS interacts with the Packet Switched Domain (e.g. Wireless LAN, GPRS, and UMTS networks), the Internet, and application services. Then we will examine the key IMS capabilities and show how they can be combined to create new mobile IP services. Finally, we present a software architecture, which is enabled by IMS and allows development of unique applications (with multimedia/multi-session functionality, single/multi-user, service to user). The software architecture is illustrated by an example of a prototype application.

Efficient routing and wavelength assignment for multicast in WDM networks

The next generation multimedia applications such as video conferencing and HDTV have raised tremendous challenges on the network design, both in bandwidth and service. As wavelength-division-multiplexing (WDM) networks have emerged as a promising candidate for future networks with large bandwidth, supporting efficient multicast in WDM networks becomes eminent. Different from the IP layer, the cost of multicast at the WDM layer involves not only bandwidth (wavelength) cost, but also wavelength conversion cost and light splitting cost. It is well known that the optimal multicast problem in WDM networks is NP-hard. In this paper, we develop an efficient approximation algorithm consisting of two separate but integrated steps: multicast routing and wavelength assignment. We prove that the problem of optimal wavelength assignment on a multicast tree is not NP-hard; in fact, an optimal wavelength assignment algorithm with complexity of O(NW) is presented. Simulation results have revealed that the optimal wavelength assignment beats greedy algorithms by a large margin in networks using many wavelengths on each link such as dense wavelength-division-multiplexing (DWDM) networks. Our proposed heuristic multicast routing algorithm takes into account both the cost of using wavelength on links and the cost of wavelength conversion. The resulting multicast tree is derived from the optimal lightpaths used for unicast.

Multimedia Document Models: Sealed Fate or Setting Out for New Shores?

Existing multimedia document models like HTML, MHEG, SMIL, and HyTime lack appropriate modeling primitives to fit the needs of next generation multimedia applications which bring up requirements like reusability of multimedia content in different presentations and contexts, and adaptation to user preferences. In this paper, we motivate and present new requirements stemming from advanced multimedia applications and the resulting consequences for multimedia document models. Along these requirements, we discuss the document model standards HTML, HyTime, MHEG, SMIL, and Z_YX, a new model that has been developed with special focus on reusability and adaptation. The analysis and comparison of the models show the limitations of existing models, point the way to the need for new flexible multimedia document models, and throw light on the many implications on authoring systems, multimedia content management, and presentation.