Information Technology Reference
In-Depth Information
1 Introduction
Many different technologies are currently being used to enable end-to-end Quality
of Service for advanced multimedia services [1]. However, for the most part, these
technologies are neither integrated within an interoperable framework nor provide
a means to effectively manage the end-to-end multimedia delivery chain. As such,
their scope of use is limited to specific applications or situations. Thus, there
exists a need for solutions based on an interoperable multimedia framework
supporting the end-to-end management of heterogeneous contents, networks, and
terminals while enabling Quality of Service (QoS), or even Quality of Experience
(QoE), for the end user.
This topic is also linked with network neutrality [2], which shall not provide
restrictions on content, sites, or platforms, on the kinds of equipment that may be
attached, and on the modes of communication allowed, as well as one where com-
munication is not unreasonably degraded by other communication streams. In
general, network neutrality is already provided in a sense that telecommunications
companies rarely offer different (QoS/QoE) rates to broadband and dial-up Inter-
net consumers. However, there are no clear legal restrictions against allowing
certain service providers to intentionally slow-down peer-to-peer (P2P) communi-
cations or to perform deep packet inspection in order to discriminate against P2P,
FTP and online games, instituting a cell-phone style billing system of overages,
free-to-telecom value-added services, and anti-competitive tying (i.e., "bundling").
Quality of Experience (QoE) [3, 4], some times also known as Quality of User
Experience, is a subjective measure from the user's perspective of the overall
value of the service provided. Although QoE is perceived as subjective, it is the
only measure that counts for customers of a service. Being able to measure it in a
controlled manner helps operators to understand what may be wrong with their
services. A framework that can be used for this purpose is the MPEG-21 multime-
dia framework, which enables the transparent and augmented use of multimedia
resources across a wide range of networks, devices, user preferences, and commu-
nities [5]. In particular, MPEG-21 provides means for the transaction of Digital
Items (i.e., multimedia resources and metadata within a standardized structure)
among Users and whose functions can be categorized into six categories: declara-
tion (and identification), digital rights management, adaptation, processing, sys-
tems, and miscellaneous aspects (i.e., reference software, conformance, etc.).
In this chapter we describe an architecture for the integrated management of the
end-to-end multimedia delivery chain that utilizes the MPEG-21 multimedia
framework [6], and that enables QoS/QoE for the end-user by adopting cross-layer
techniques [7]. As this architecture has been developed in the course of the
ENTHRONE II project [8], it is referred to as the ENTHRONE Integrated Man-
agement Supervisor (EIMS). Furthermore, we describe a QoS/QoE model ena-
bling one to measure the perceptual quality of video transmissions by exploiting
metrics from different layers (service, application and network) in an interoperable
way. As such we are able to keep the quality as experienced by the end user at a
