May El Barachi

The design and implementation of architectural components for the integration of the IP multimedia subsystem and wireless actuator networks

The IP multimedia subsystem is becoming the de facto standard for IP-based multimedia services, while wireless sensor networks are gaining in popularity due to their ability to capture a rich set of contextual information. Integrating the sensing capabilities of WSNs in the IMS can open the door to a wide range of context-aware applications in areas such as wireless healthcare and pervasive gaming. We have previously proposed a presence-based architecture for WSN/IMS integration. This architecture relies on two key components: a WSN/IMS gateway acting as an interworking unit between WSNs and the IMS; and an extended presence server serving as a context information management node in the core network. In this article we focus on the design and implementation of these two components. Furthermore, two applications (a pervasive game and a personalized call control application) are used to concretely show how new applications can be developed using our architecture. Performance has also been evaluated. Several important findings were made in the course of this work; one is that the IMS integration with a large and evolving variety of WSNs may be a never-ending endeavor - the gateway requiring constant upgrading due to the lack of standard APIs for the interaction with sensors produced by different vendors. Another finding is that while the introduction of context as an application building block in the IMS ensures the availability of additional contextual information in the network and enables fast and easy development of context-aware applications, the lack of mature IMS application development toolkits remains a roadblock.

Mobile Phone Sensing as a Service: Business Model and Use Cases

With the ubiquity and ever-increasing capabilities of mobile devices and the integration of more and more sensors in them, such devices now have the potential to act not only as personal communication and computing platforms but also as sensing platforms. Mobile phone sensing is a complementary and radically different sensing approach in which smartphones fulfill the sensing role (instead of dedicated wireless sensor networks), by acting as super sensor nodes and gateways. There are several motivations behind the mobile phone sensing approach, such as: Increased sensing coverage area due to phones mobility, enhanced information processing/validation capabilities, the addition of a social dimension to sensing, and the easy on-demand deployment of new sensors. In this paper, we propose a new business model for mobile phone sensing environments, and elaborate a new identification and charging scheme to support its operation. A number of use cases related to mobile phone sensing are also presented. The proposed business model promotes the idea of Mobile Sensing as a Service, in which a number of mobile sensing terminal operators offer their sensed data as a service to the network operator, which can then disseminate it to interested entities (e.g. specific users, communities, and network nodes).

Contextware Research Challenges in Ambient Networks

Network-centric context information is used to make networks more receptive to the users’ needs by personalizing the communication process and making it more sensitive to changes that may occur in the surroundings. As such, it is a natural step that context awareness should be suitably incorporated within traditional networks in order to create an ‘ambient network’. This approach is aimed at enabling the co-operation of heterogeneous networks on demand, transparently to the potential users, and without the need for preconfiguration or offline negotiation between network operators. This paper discusses the approach taken by authors to incorporate context-awareness into ambient networking concepts. It discusses how network-related context information should be utilized in ambient networks for the end user to fully experience the pervasiveness of a network and the research challenges arising from this utilization. The paper also evaluates the benefits of employing context information and contextware concepts in ambient networks.

Graph-theoretic characterization of cyber-threat infrastructures

In this paper, we investigate cyber-threats and the underlying infrastructures. More precisely, we detect and analyze cyber-threat infrastructures for the purpose of unveiling key players (owners, domains, IPs, organizations, malware families, etc.) and the relationships between these players. To this end, we propose metrics to measure the badness of different infrastructure elements using graph theoretic concepts such as centrality concepts and Google PageRank. In addition, we quantify the sharing of infrastructure elements among different malware samples and families to unveil potential groups that are behind specific attacks. Moreover, we study the evolution of cyber-threat infrastructures over time to infer patterns of cyber-criminal activities. The proposed study provides the capability to derive insights and intelligence about cyber-threat infrastructures. Using one year dataset, we generate notable results regarding emerging threats and campaigns, important players behind threats, linkages between cyber-threat infrastructure elements, patterns of cyber-crimes, etc.

Context-Aware Signaling for Call Differentiation in IMS-Based 3G Networks

Service differentiation is an active topic in 3G networks, which aim at supporting a diversity of IP multimedia services (with different QoS requirements) and users (establishing sessions with different levels of importance). In this paper, we propose a network level call differentiation scheme in IMS-based 3G networks. This scheme defines three new classes of calls offering different priorities/guarantees to the user. Service differentiation is achieved at the session signaling level by relying on a context-aware resource allocation strategy. An extension to the 3GPP IMS architecture is proposed to realize the service differentiation scheme and a proof-of-concept prototype is built using SIP and COPS as implementation technologies. Unlike other signaling level schemes, the system proposed here offers flexible QoS negotiation mechanisms to the user, provides preferential treatment at the beginning and during sessions, and takes into consideration the characteristics of the multimedia, multiparty, service environment offered by 3G networks.

Developing applications for internet telephony: A case study on the use of web services for conferencing in SIP networks

Applications offered to end‐users as value‐added services play a vital role in the success of Internet telephony service providers. Today’s standard frameworks for developing them have several shortcomings that motivate the need for novel frameworks. Web services are an emerging paradigm for program‐to‐program interactions over the Internet. This paradigm is a prime candidate for application development in Internet Telephony because it may aid in addressing the drawbacks of today’s standard frameworks. This paper presents a case study that gives insights in the suitability of Web services as a standard framework for the development of conferencing applications in Internet Telephony. The case study includes the definition and the implementation of a novel Web service for conferencing, the implementation of the conference server in a SIP environment, the development of several conferencing applications (including a game), and performance evaluation. Based on this case study, we conclude that Web services are very promising for conferencing application development in Internet Telephony, especially as the performance can be significantly improved with the emerging techniques that are briefly discussed in the paper.

The Design and Implementation of a Gateway for IP Multimedia Subsystem/Wireless Sensor Networks Interworking

The IP Multimedia Subsystem (IMS) is becoming the de-facto standard for IP-based multimedia services, while Wireless Sensor Networks (WSNs) are gaining a lot of popularity due to their ability of capturing a rich set of contextual information and their high application potential. Making the rich set of contextual information, captured by WSNs, available to the IMS can greatly enhance its service provisioning capabilities and open the door to a wide range of novel multimedia services. We have previously proposed a solution for WSNs/IMS integration. One of the key components of this solution is a WSN/IMS gateway acting as intermediary between the two networks. This paper focuses on the design and implementation of this gateway. The gateway architecture proposed encompasses the information management and support functions needed to enable IMS interaction with different types of WSNs. A prototype of this architecture is built and tested using Ericssons IMS simulated environment. Furthermore, two applications (a pervasive game and a personalized call control application) are used to demonstrate the system operation.

Control-level call differentiation in IMS-based 3G core networks

The 3GPP-defined IP Multimedia Subsystem is becoming the de facto standard for IP-based multimedia communication services. It consists of an overlay control and service layer that is deployed on top of IP-based mobile and fixed networks, in order to enable the seamless provisioning of IP multimedia services to 3G users. Service differentiation, which implies the networks ability to distinguish between different classes of traffic (or service) and provide each class with the appropriate treatment, is an important aspect that is considered in 3G networks. In this article, we present a critical review of existing service differentiation solutions and propose a new control-level call differentiation solution for IMS-based 3G core networks. The solution consists of a novel call differentiation scheme, enabling the definition of various categories of calls with different QoS profiles. To enable the support of such profiles, an extended IMS architecture, relying on two adaptive resource management mechanisms, is proposed. Furthermore, simulations are used to evaluate the system performance. Compared to existing service differentiation solutions, our solution offers several benefits, such as: flexible QoS negotiation mechanisms, control over many communication aspects as means for differentiation, and a dynamic and adaptive resource management strategy.

Challenges in modeling and disseminating context information in ambient networks

The concept of Ambient Networks (AN) aims at enabling the co-operation between heterogeneous networks on demand, in order to provide ubiquitous connectivity to end-users. This could be achieved by seamlessly incorporating context-awareness which plays a vital role in supporting autonomic decision making in ANs, while giving rise to new types of applications and services. Modeling and disseminating contextual information in a rapidly changing time-constrained heterogeneous environment, transparently to the potential users, is a challenge. This paper discusses these complications with an evaluation of the existing context modeling and dissemination approaches, with respect to ambient networking requirements.

Adaptive SLA-based elasticity management algorithms for a virtualized IP multimedia subsystem

The IP Multimedia System (IMS) is an important reference service delivery platform for next generation networks and is considered as a de-facto standard for IP-based multimedia communication services. In its current design, the IMS faces important challenges in terms of scalability and elasticity, and lacks the ability to adaptively manage the network resources and dynamically dimension the network nodes based on load and demand. Network function virtualization and cloud computing are two important concepts that can be leveraged to address those challenges in IMS environments. In this work, we propose two adaptive SLA-based elasticity management algorithms for virtualized IMS environments. Our proposed algorithms use two SLA attributes (the call setup delay and user priority) to dynamically control the CPU resources allocated/de-allocated to virtualized IMS nodes. The aims of our proposed algorithms are: 1) to ensure efficient usage and sharing of CPU resources by various IMS components; 2) to reduce the overall power consumption in virtualized IMS platforms; and 3) to enhance the user experience when using IMS networks. We have tested the proposed algorithms by setting up a virtualized IMS environment using OpenIMS Core and Xen as the hypervisor. The results obtained show that our proposed algorithms meet the SLA constraints, even when subjected to dynamic load, thereby enhancing the overall QoS. We have also compared the proposed algorithms with Xen Servers existing CPU resource scaling governors and the results indicate that our algorithms work better when compared to the existing governors.