Abstract
The electrical compensation of chromatic dispersion (CD) and polarization mode dispersion (PMD) in a coherent optical system exploiting polarization multiplexing is discussed in this paper. The benefits of combining a phase estimation algorithm with a decision directed least-mean-square equalizer in a feedback configuration is reported.

Abstract
In this paper, we study the effect of uplink wise on the optimality of the receiver structure proposed in [1][2]. This optimum receiver is composed by a demodulator that extracts a set of sufficient statistic, and by an ML detector that uses the demodulator output to estimate the original data, We concentrate on Intensity Modulation/Direct Detection (IM/DD) Radio-over-Fiber (RoF) uplink system when OFDM signals suffer from noise generated by the antenna and photodiode and from nonlinear distortion. The results show that for small and medium modulalion index values, the uplink noise maintains its Gaussian distribution and the optimum receiver still outperforms the conventional.

Abstract

Abstract
The MPEG-21 standard forms a comprehensive multimedia framework covering the entire multimedia distribution chain. In particular, it provides a flexible approach to represent, process, and transact complex multimedia objects which are referred to as Digital Items (DIs). DIs can be quite generic, independent of the application domain, and can encompass a diversity of media resources and metadata. This flexibility has an impact on the level of interoperability between systems and applications, since not all the functionality needs to be implemented. Furthermore, additional semantic rules may be implemented through the processing of the Digital Item which is possibly driven by proprietary metadata. This jeopardizes interoperability and consequently raises barriers to the successful achievement of augmented and transparent use of multimedia resources. In this context, we have investigated and evaluated the interoperability at the semantic level of Digital Items throughout the automated production, delivery and consumption of complex multimedia resources in heterogeneous environments. This paper describes the studies conducted, the experiments performed, and the conclusions reached towards that goal. © Copyright 2008 ACM.

Abstract
This paper addresses multimedia end user system design for content distribution over heterogeneous networks and terminals, with particular focus on End-to-End quality of service (QoS) control. A multimedia terminal comprising content-related metadata processor, usage environment characteristics provider, end user QoS monitor and H.264's extension Scalable Video Coding (SVC) audio-visual player in coordination under a terminal middleware, has been conceived and implemented. This end user terminal enables End-to-End QoS control for content adaptation solution both in semantic and physical approaches to maximize end user's perceptual experience and minimize resources. Such design approach illustrates a possible architecture for next generation multimedia end user terminal supporting MPEG-21 and H.264's extension SVC codec standards.

Abstract
With the advent of the World Wide Web (WWW), large volumes of multimedia content are now available on-line in multiple formats. Furthermore, with the proliferation in the mass market of a diversity of multimedia-enabled end-user devices, consumers increasingly expect to be able to access any kind of content anywhere and at any time, regardless of the capabilities of their terminals and the networks to which they are attached. Access to content that meets user expectations and demands, must take into account all the different aspects of this Peterogeneous environment. This paper describes the approach adopted within the European project ENTHRONE-2 to address this challenge. ENTHRONE-2 has conceived, designed and implemented a distributed platform, based on open standards, notably MPEG-21 and Web Services technologies, that supports the kind of network multimedia content access users expect. In particular, it focus on the ENTHRONE Integrated Management Supervisor, the entity that coordinates all the actions required for the provision of quality and context-aware, multimedia services to end-users.