Badis Tebbani’s research while affiliated with Sorbonne University and other places

Several technical issues make commercial and large voice over wireless local area network (VoWLAN) services difficult to provide. The most challenging issue when voice over Internet Protocol (VoIP) services are ran over IEEE 802.11-based WLANs is the bandwidth inefficiency due to the considerable overhead associated with WLAN packet transmission. In this work, we propose a session-based quality-of-service management architecture (SQoSMA) to overcome the low number of VoIP calls in IEEE 802.11 Wireless LANs and the negative effect of new call addition when the WLAN reaches its capacity. The SQoSMA combines data and control planes to detect VoWLAN QoS degradations and performs either an adaptive audio codec switching or a call stopping to fix VoWLAN issues in a differentiated services manner. In addition, our solution deals with user sessions information, by considering user priority (from its agreement) to guarantee a certain level of its multimedia applications. Performance evaluation using a real test-bed shows that call codec change and call stopping techniques can easily assure high-priority calls with acceptable call blocking probability.

The increasing popularity of WLANs-due to the use of license-free radio spectrum with low-cost, easily deployable and high-data-rate wireless services- has encouraged service providers to consider deploying them in high density usage areas, such as public hotspots, to provide complementary broadband access to their networks and services. This article proposes a Session Initiation Protocol based QoS management architecture that aims to provide consistent QoS control for multimedia applications (VoIP, VoD, ...) over wireless access networks. In particular, we will present a generic QoS based management architecture for decentralized management of multimedia applications over wireless access networks, such as WLAN. We will apply our architecture to the management of the WLAN in order to assure QoS (throughput and delay) for the delivered multimedia applications according to users' priorities and providers' objectives. Performance evaluations are discussed to illustrate the feasibility and the efficiency of the proposed architecture through the implementation of a real-world testbed.

Voice over Wireless LAN (VoWLAN) is becoming more and more helpful in our life and is expected to be among the most important applications in next generation networks. However, the maximum number of VoIP sessions that a WLAN can ensure is very small. Moreover, when the WLAN reaches its capacity the addition of one VoIP session affects the QoS parameters of all VoIP sessions. In this paper, we propose an adaptive technique to ensure the active VoIP sessions of users with high priority (from a provider perspective). Thus, in order to guarantee the quality of high priority sessions, we propose to downgrade the quality (low but acceptable MOS) of user sessions with low priority by changing their used codecs (e.g., ITU G729 instead of ITU G711). This technique and all related monitoring functions are defined into the proposed session-based QoS management architecture. In order to validate our approach a complete test-bed is made up by which we have performed some feasibility and gain tests.

Growing demands for the public wireless broadband services will require more capacity than the one provided by IP-based service providers (ISPs). The increasing popularity of WLANs due to the use of license-free radio spectrum with low-cost, easily deployable, high-data-rate wireless services, has encouraged service providers to consider their deployment in high density usage areas such us public hotspots to provide complementary broadband access to their networks and services. In order to provide consistent QoS control for multimedia applications (VoIP, VoD,...) over hotspots, a Session Initiation Protocol (SIP) based QoS management architecture is proposed in this article. Performance evaluations are discussed to illustrate the feasibility of the proposed architecture.

In this paper, we contribute on the service-driven management of quality of service and user access in wireless corporate networks. We propose a Service-Level Agreement (SLA) oriented nomadism management architecture with a top-down vision starting by the specification of company objectives and going down to device-level configurations. We define an algorithm for the automatic translation of application-level quality assurance parameters into network-level configuration parameters. A prototype implementation of our solution to the SLA-driven enterprise nomadism management is presented along with preliminary results on the self-adaptive capabilities of our QoS mapping algorithm.

In this article, we focus on the service-driven management of quality of service and user access in wireless corporate networks. We propose a service-level agreement (SLA) oriented nomadism management architecture with a top-down vision starting by the specification of company objectives and going down to device-level configurations. We define an algorithm for the automatic translation of application-level quality assurance parameters into network-level configuration parameters. The description of the prototype implementation of our solution to the SLA-driven enterprise nomadism management is given and preliminary results on the self-adaptive capabilities of our mapping algorithm are given.

In this work we propose GXLA, a language for the specification of Service Level Agreements (SLA). GXLA represents the implementation of the Generalized Service Level Agreement (GSLA) information model we proposed in a previous work. It supports multi-party service relationships through a role-based mechanism. It is intended to catch up the complex nature of service interactivity in the broader range of SLA modeling of all sorts of IT business relationships. GXLA is defined as an XML schema which provides a common ground between the entities in order to automate the configuration. GXLA can be used by service providers, service customers, and third parties in order to configure their respective IT systems. Each party can use its own independent SLA interpretation and deployment technique to enforce the role it has to play in the contract. An illustrative VoIP service negotiation shows how GXLA is used for automating the process of SLA negotiation and deployment.

In this work, we focus on Service Level Agreement "SLA" driven nomadism management in wireless corporate networks. We adopt a novel top down approach in dealing with this problem. We aim at automatic equipment configuration based on high level company objectives and strategies for nomadism. For that, we propose a service-oriented management architecture, which starts at the specification of company objectives and strategies and down through SLAs until reaching instance level configurations.