Julien Arnaud

Flexible User Profile Management for Context-Aware Ubiquitous Environments

With the important advent of multimedia services and the ubiquity of computing environments, the concept of context-awareness in services access and provisioning is getting crucial. Services, especially the multimedia ones, must perform automatically actions/operations to adapt the delivered content to the user expectations and his environment capabilities, thus ensuring the best quality of experience. To facilitate the adaptation process, we introduce a flexible context-sensitive user profile model that gathers static and dynamic data characterizing the user and his operational context. An efficient framework for managing and delivering the user profile is also proposed. A context-dependent user profile instance is created for each application according to its adaptation process needs. This paper also presents some implementation issues of the developed prototype together with an IPTV streaming use case.

Adaptive IPTV services based on a novel IP Multimedia Subsystem

Heterogeneous communication devices are emerging and changing the way of communication. Innovative multimedia applications are now accessible through these embedded systems. The 3GPP IP Multimedia Subsystem (IMS) provides a basic architecture framework for the Next Generation Network (NGN) supporting the convergence platform for service provisioning in heterogeneous networks. ETSI TISPAN standardization effort focuses on delivering IPTV services on such platform. Nevertheless, IPTV on IMS standardization suffers from a lack of efficient user-centric network management mechanisms as the end-user may consume IPTV service from different access networks, on different mobile devices, at anytime. User’s Perceived Quality of Service (PQoS) or Quality of Experience (QoE) of IPTV service may also suffer from wireless access network impairments. This paper introduces new functionalities in IPTV over IMS architecture which optimize satisfaction of the end-user and resource utilization of the operator’s networks. A context-sensitive User Profile (UP) model is used to deliver IPTV streams adapted to the user’s environment. In order to optimize the operator network usage, the impact of spatiotemporal dynamics of the video content on the deduced perceptual quality is considered. A Multimedia Content Management System (MCMS) is proposed to perform dynamic cross-layer adaptation of the IPTV stream based on PQoS measurements at the end-user side.

IPTV QoS adaptation for multi-homed mobile terminals in a new IMS based architecture

With the emergence of multimedia applications that have real constraints, ensuring a satisfying quality of service to mobile users presents a big challenge in heterogeneous wireless networks. In such environment, the asymmetry of the available resources as well as user’s mobility can cause offered QoS degradation. In this paper, we propose the use of the Stream Control Transmission Protocol (SCTP) within a QoS adaptive IPTV services in a novel IMS architecture. The multi-homing feature and the partial reliability extension allow improving the network performance and increasing the user satisfaction. In addition, we have proposed an mSCTP based mobility scheme to guarantee service continuity during handover to IPTV users over IMS. The handover decision includes Perceived QoS (PQoS) measurement reflecting the user satisfaction and Media Independent Handover (MIH) information. An analytical study of the time required to perform IPTV adaptation, show that our approach improves the performance by minimizing the delay and maximizing the user satisfaction.

Using PR-SCTP for IPTV QoS adaptation over IMS network

In recent years, we have seen the emergence of realtime applications that have delay and reliability constraints. The challenge of the transport protocol is to provide a reliable service while reducing the delay. SCTP is a reliable transport protocol that have inherited the best characteristics of TCP and UDP and provided new attractive features such as multi-homing and multi-streaming. In this paper, we suggest the use of SCTP with the partial reliability extension as a transport protocol for the IPTV services in the IMS network, in order to improve the network performance and maximize the user satisfaction. Moreover, we have proposed an mSCTP based mobility scheme to guarantee service continuity during handover to IPTV users over IMS.

Adapted IPTV service within novel IMS architecture

The paper introduces a novel architecture to be used in IMS (IP Multimedia Sub-system) context. Thanks to the use of a MCMS (Multimedia Content Management System) along with interoperable components, the proposed solution enables an efficient adaptation of services according to the Perceived Quality of Service degradation at the end-user side.

Mobility-aware P/I-CSCF: A solution for achieving seamless handover in IMS

This paper is focusing on IMS session continuity of a Mobile Node (MN) roaming from different access technologies. Comparison between different mobility solutions used in NGNs are addressed. Vertical mobility using End-User context information and SIP signaling are foreseen to efficiently comply to 3GPP standards and to provide enhanced end-user satisfaction. The usage of SIP mobility within our solution does not introduce any change in the signaling functionalities nor the architecture. Only slight modifications are required in the P-(or I-)CSCF in order to enable media switching. This paper also introduces a new algorithm in the MN to handle incoming media from different network interfaces. A proof-of-concept involving wlan to 3G mobility validates our analysis and provide interesting results.

Flow scheduling at multihomed devices during vertical handover in NGN

Mobile Nodes (MNs) are nowadays equiped with several network interfaces. Multihomed equipment can benefit from the network diversity to increase end-user satisfaction. In NGN based technologies, such as IMS, vertical handover still suffers from roaming from different access technologies and session continuity between heterogeneous network interfaces is still under study. Vertical mobility using End-User context information and SIP signaling is foreseen to efficiently comply to 3GPP standards and provide enhanced end-user satisfaction. QoE estimation are usually derived from media QoS information. This paper focuses mainly on media switching while performing a vertical handover. A new algorithm handling incoming media from different network interfaces is introduced. A proof-of-concept involving WLAN to 3G mobility validates our analysis and provides interesting results.