Smart networks have grown out of the need for stable, reliable, and predictable networks that will guarantee packet delivery under Quality of Service (QoS) constraints. In this article we present a measurement-based admission control algorithm that helps control traffic congestion and guarantee QoS throughout the lifetime of a connection. When a new user requests to enter the network, probe packets are sent from the source to the destination to estimate the impact that the new connection will have on the QoS of both the new and the existing users. The algorithm uses a novel algebra of QoS metrics, inspired by Warshall's algorithm, to look for a path with acceptable QoS values to accommodate the new flow. We describe the underlying mathematical principles and present experimental results obtained by evaluating the method in a large laboratory test-bed operating the Cognitive Packet Network (CPN) protocol.

The increasing necessity to have wireless sensor nodes capable to be active for a long time without battery recharge asks for technologies and methods that can anticipate the level of energy drain in these devices. In this paper a modelling approach based on Fluid Stochastic Petri Nets is proposed. The main contribution of the paper is the definition of a model to estimate single node performance in presence of several energy consuming entities. The definition of this single node model is relevant in order to properly support the design of more complex network topologies. The paper also reports first experimental results on model analysis mainly conducted by simulation.