PQoS Assessment Methods for Multimedia Services

PQoS Assessment Methods for Multimedia Services

Harilaos Koumaras (National Center of Scientific Research, “Demokritos”, Greece), Fidel Liberal (University of the Basque Country, Spain) and Lingfen Sun (University of Plymouth, UK)
DOI: 10.4018/978-1-59904-820-8.ch013
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The concept of PQoS, although in general it deals with the user satisfaction with a specific delivered/ requested service, is in practice significantly differentiated by the nature of each delivered service. This chapter reviews various existing PQoS assessment methods for video, VoIP, online games, and Web services that have been published in the literature. It then moves beyond the current PQoS assessment methods and presents novel techniques for predicting the PQoS of a multimedia service.
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The term quality of service (QoS) has been widely used in various IT services throughout time, from traditional ones, such as those related to telephony to more recent ones (e.g., those provided over IP networks). Although multiple definition of QoS concept exists (one such a detailed compilation can be found in (ITU-T, 2004a)), most of the proposed definitions agree on considering quality of service as “a set of characteristics related to the performance of the elements that provide the services that have an effect into final end users perception.”

Since different services may be affected by a different set of parameters, some kind of categorization of QoS is necessary. This has led to the definition of the traffic and service classes, with each of them corresponding to a different subset of parameters. However, most of traditional QoS assessment and management architectures handle a technical only subset of these parameters (only network performance is considered here) (Xilouris, Kourtis, & Stefanou, 2005).

On the other hand, as early as 1994, ITU-T E.800 recommendation (ITU-T, 1994) included a more user-centric definition of Quality of Service as “the collective effect of service performance, which determines the degree of satisfaction of a user of the service.”

Therefore, the term QoS makes a step beyond pure performance-related concepts, such as network performance (NP) or service performance (SP). Yet, when Internet services are the focus point, NP is found to be one of the most significant factors due to the high variability of the performance parameters in data networks today. Inherent characteristics of these networks, such as non-connection-oriented or best effort properties, make the provision of a minimum level of guaranteed NP a complex issue. As a result, the research community has focused, during the last two decades, on the so-called “Technical QoS” (TQoS) or “Network QoS” (NQoS), trying to solve the problem of assuring an accurate performance level to end-users.

The QoS perceived as user satisfaction has received less effort from the research community through past years. One of the first formal inclusions of QoS as perceived by users of Internet services was in ETSI ETR 003, (ETSI, 1994) wherein a quality matrix was proposed to relate network and service performance to the quality of service perceived by end users. This approach was later adopted by ITU-T (ITU-T, 2004a). In both recommendations, ETSI and ITU-T brought together objective aspects related to Network Performance and their subjective impact on user satisfaction.

Thus, NP parameters are key issues in QoS, however, these parameters have to be considered together with other factors (such as codecs, source/terminal mechanisms) for an overall user satisfaction or an end-to-end perceived QoS (PQoS).

Furthermore, a common vision of the future communication networks is the provision of multimedia or audiovisual content at a variety of quality and price levels (Seeling, Reisslein, & Kulapala, 2004). The evaluation of the PQoS will provide an end user with a range of potential choices, covering the possibilities of low, medium, or high quality levels. This PQoS evaluation will also give the service provider and network operator the capability to minimize the storage and network resources by allocating only the ones that are necessary to maintain a specific level of user satisfaction (Gardikis, Kourtis, & Constantinou, 2003).

Further, the success of providing novel multimedia services over wired/wireless networks depends on how good the quality of the service is and whether it meets or not an end user’s satisfaction standards. Thus, it is critical for equipment manufacturers, network operators and service providers to assess, predict and possibly control the end-to-end perceptual multimedia (e.g., voice and video) quality for commercial and technical reasons. Developing accurate, efficient and robust PQoS models for multimedia services remains a challenging research target both in academia and industry.

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List of Reviewers
Table of Contents
Abbas Jamalipour
Nicola Cranley , Liam Murphy
Chapter 1
Ronan Skehill, William Kent, Dorel Picovici, Michael Barry, Sean McGrath
This chapter introduces quality of service in multi-access wireless networks. Specifically it demonstrates how QoS is implemented in IEEE 802.11 and... Sample PDF
Evaluating QoS in a Multi-Access Wireless Network
Chapter 2
Dirk Staehle, Andreas Mäder
This chapter gives an overview of the background and functionality of the high speed downlink packet access (HSDPA), and provides insights into the... Sample PDF
Radio Resource Management Strategies for HSDPA-Enhanced UMTS Networks
Chapter 3
Nidal Nasser, Tarek Bejaoui
Major research challenges in the next generation of wireless networks include the provisioning of worldwide seamless mobility across heterogeneous... Sample PDF
Handoff Management in Next Generation Wireless Networks
Chapter 4
Ming Li, Roberto Riggio, Francesco De Pellegrini, Imrich Chlamtac
This chapter provides a comprehensive review of the architectures, algorithms, and protocols in the topic of resource management in IEEE... Sample PDF
Resource Management in IEEE 802.11 Based Wireless Networks
Chapter 5
Anna Sfairopoulou, Carlos Macián, Boris Bellalta
Network Technologies and Strategies (NeTS) Research Group, Universitat Pompeu Fabra, SpainThis chapter introduces the problems caused to voice over... Sample PDF
Adaptive Codec Selection for VoIP in Multi-Rate WLANs
Chapter 6
Michael M. Markou, Christos G. Panayiotou
This chapter introduces the network buffer control techniques as a mean to provide QoS. This problem has been extensively studied in the context of... Sample PDF
Buffer Control Techniques for QoS Provisioning in Wireless Networks
Chapter 7
Gabriel-Miro Muntean, Janet Adams
Wireless networks are becoming a part of everyday life for many people. When a mobile device has wireless LAN capability, multimedia content can be... Sample PDF
Power Saving in Wireless Multimedia Streaming to Mobile Devices
Chapter 8
Jose Luis Jodra, Fidel Liberal, Begoña Blanco Jauregi
This chapter introduces the principal characteristics of MANETs and shows how these particularities may affect both QoS conditions and QoS... Sample PDF
Multimedia Services Provision in MANETs
Chapter 9
Andrej Kos, Mojca Volk, Janez Bester
Commonly understood as the next generation networks (NGN), a composite environment of proven telecommunications and Internet-oriented mechanisms has... Sample PDF
Quality Assurance in the IMS-Based NGN Environment
Chapter 10
Marcio Nieblas Zapater, Graça Bressan
This chapter discusses the quality assurance of multimedia services over IP networks from the end user standpoint and introduces the concept of... Sample PDF
Quality of Experience for Video Services
Chapter 11
Dorel Picovici, John Nelson
Perceptual voice quality measurement can be defined as an objective quantification of an overall impression of the perceived stimulus. An... Sample PDF
Perceptual Voice Quality Measurements for Wireless Networks
Chapter 12
Tacha Serif, Gheorghita Ghinea
This chapter describes an investigation exploring user experiences of accessing streamed multimedia content, when that content is tailored according... Sample PDF
Enhancing the Multimedia Tour Guide Experience: Transmission Tailoring Based on Content, Location, and Device Type
Chapter 13
Harilaos Koumaras, Fidel Liberal, Lingfen Sun
The concept of PQoS, although in general it deals with the user satisfaction with a specific delivered/ requested service, is in practice... Sample PDF
PQoS Assessment Methods for Multimedia Services
Chapter 14
Peifang Zhang, Scott Jordan
Emerging wideband code division multiple access (WCDMA) data services will likely require resource allocation to ensure that throughput targets are... Sample PDF
Scheduling and Access Control for Wireless Connections with Throughput Guarantees
Chapter 15
Paolo Chini, Giovanni Giambene, Snezana Hadzic
Nowadays there is an increasing need of broadband communication anytime, anywhere for users that expect to receive multimedia services with support... Sample PDF
Broadband Satellite Multimedia Networks
Chapter 16
Panagiotis Papadimitriou, Vassilis Tsaoussidis
An increasing demand for multimedia data delivery coupled with reliance in best-effort networks, such as the Internet, has spurred interest on... Sample PDF
End-to-End Support for Multimedia QoS in the Internet
Chapter 17
Tarek Bejaoui, Nidal Nasser
This chapter introduces the cross layer design for resource allocation over multimedia wireless networks. Conventional layered packet scheduling and... Sample PDF
Cross-Layer Radio Resource Management Protocols for QoS Provisioning in Multimedia Wireless Networks
Chapter 18
Gürkan Gür, Suzan Bayhan, Fatih Alagöz
This chapter introduces the QoS issues and support in transport protocols for wireless multimedia transmission. After an overview of the transport... Sample PDF
Transport Protocols and QoS for Wireless Multimedia
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