Catálogo de publicaciones - libros

Nowadays WSNs support applications such as target tracking, environmental control or vehicles traffic monitoring. Generally, these applications have strong and strict requirements for end-to-end delaying and loosing during data transmissions. In this paper, we propose a practical scenario for application of the WSN field in order to illustrate selection of an appropriate approach for guaranteeing performance in a WSN-deployed application. The methodology we have used includes four major phases: 1) Requirements analysis of the application scenario; 2) QoS modelling in different layers of the communications protocol stack and selection of more suitable QoS protocols and mechanisms; 3) Definition of a simulation model based on an application scenario, to which we applied the protocols and mechanisms selected in phase 2; 4) Validation of decisions by means of simulation; and 5) analysis of results. This work has being partially developed in the framework of the CRISAL - M0700204174 project (partially funded by “Universidad Politécnica de Madrid” and “Comunidad de Madrid”, Spain).

Autonomic computing environments rely on devices that are able to make intelligent decisions without human supervision. Automated Trust Negotiation supports the cooperation of devices with no prior trust relationship. They can reach an agreement by iteratively exchanging credentials during a negotiation process. These credentials can serve as authorization tokens or may carry information that becomes a parameter of the further service usage. A careful negotiation strategy helps in protecting sensitive credentials that must only be available to authorized entities. We introduce the framework that supports a stateless negotiation protocol to reach comprehensive agreements. We argue how this approach applies to autonomic environments and demonstrate its scalability.

Today networks suffer from various challenges like distributed denial of service attacks or worms. Multiple different anomaly-based detection systems try to detect and counter such challenges. Anomaly-based systems, however, often show high false negative rates. One reason for this is that detection systems work as single instances that base their decisions on local knowledge only.

In this paper we propose a collaboration of neighboring detection systems that enables receiving systems to search specifically for that attack which might have been missed by using local knowledge only. Once such attack information is received a decision process has to determine if a search for this attack should be started. The design of our system is based on several principles which guide this decision process. Finally, the attack information will be forwarded to the next neighbors increasing the area of collaborating systems.

This paper describes a metamodeling strategy of Service Level Agreements for Digital Video Broadcasting services based on Service Level Agreement Language(SLAng). The purpose of the paper is to provide a detailed analysis of SLAs in this domain and provide a motivation for modeling and automating their management. We also discuss why precise and machine readable SLAs can improve the levels of automation in SLA Management thereby reducing potential violations. The meta-modeling approach based on the Model Driven Architecture(MDA) described in this paper also simplifies the integration of a SLA Management systems with other infrastructure that delivers the service to the client.