Cross-Layer Scheduling Design for Multimedia Applications over Cognitive Ad Hoc Networks

In this paper,we study cross-layer scheduling scheme on multimedia application which considers both streaming traffic and data traffic over cognitive ad hoc networks.A cross-layer design is proposed to optimize SU's utility,which is used as an approach to balance the transmission efficiency and heterogeneous traffic in cognitive ad hoc networks.A framework is provided for utility-based optimal subcarrier assignment,power allocation strategy and corresponding modulation scheme,subject to the interference threshold to primary user(PU) and total transmit power constraint.Bayesian learning is adopted in subcarrier allocation strategy to avoid collision and alleviate the burden of information exchange on limited common control channel(CCC).In addition,the M/G/l queuing model is also introduced to analyze the expected delay of streaming traffic.Numerical results are given to demonstrate that the proposed scheme significantly reduces the blocking probability and outperforms the mentioned single-channel dynamic resource scheduling by almost 8%in term of system utility.

ZTE Teams with Polkomtel to Deliver Unprecedented Access to Multimedia Applications

ZTE Corporation,a leading global provider of telecommunications equipment and network solutions,announced on June 6,2007 that it has signed a strategic cooperation agreement with Polkomtel S.A.,one of the top three mobile telephony operators in Poland.

QoE Modeling and Applications for Multimedia Systems

Ireproving the quality and experience perceived by the user is fundamental when de- veloping multimedia technologies, products, and services. Quality of experience （QoE） involves subjective perception, user behavior and needs, appropriateness, con- text, and usability of delivered content. Modeling QoE is critical for enhancing QoE in various nmhimedia applications. In this special issue,

Application of Multimedia and Internet Technology in Learning Mould Design

With the use of multimedia which combines the use o f text, sound, images, motion video and animation, it is more efficient for studen ts to learn mould design interactively. A program is created using several multi media software to simulate the mechanism of moulding processes in order to let s tudents understand the concept of mould design. In addition, students can even access the program through the Internet. Therefore, the software is defined as Multimedia and Internet Technology (MIT) program. The MIT program consists of four sections: (i) simulation of mould mechanisms, ( ii) cooling system, (iii) material information and (iv) games for tutorials. Sec tion One covers the basic operations of different types of moulds such as two-p late mould, three-plate mould, split mould, side-core mould and mould with und ercuts. Section Two introduces different types of cooling systems such as bubble r, baffle, cooling circuits, etc. Section Three provides some useful material in formation for mould design. Section Four contains games of matching mould compon ents, mould design problem finding and multiple choice questions to test student s how much they understand mould design concept. Multimedia is highly effective particularly in teaching and learning. It changes the nature of learning itself. It makes reading dynamic by giving words an impo rtant new dimension. It allows students to see, hear and do simultaneously, thus significantly reducing average learning time. Furthermore, through cooperative learning on Internet, students can access the program, share data or search info rmation anytime anywhere. Therefore, Multimedia and Internet Technology is one o f the vital aspects to speed up the realization of information age in society.