F. Delli Priscoli

Structurally stable output regulation of nonlinear systems

We address a number of issues that were left open in earlier works on the subject of output regulation of nonlinear systems, and we describe an approach to structurally stable regulation that unifies and extends a number of existing results. Moreover, we also address in part the issue of robust regulation, i.e. the issue of achieving regulation in the presence of parameter uncertainties ranging within a prescribed set.

A New Approach to Adaptive Nonlinear Regulation

This paper shows how the theory of adaptive observers can be effectively used in the design of internal models for nonlinear output regulation. The main result obtained in this way is a new method for the synthesis of adaptive internal models, which substantially enhances the existing theory of adaptive output regulation by allowing nonlinear internal models and more general classes of controlled plants.

Adaptive observers as nonlinear internal models

This paper shows how the theory of nonlinear adaptive observers can be effectively used in the design of internal models for nonlinear output regulation. The theory substantially enhances the existing results in the context of adaptive output regulation, by allowing for not necessarily stable zero dynamics of the controlled plant and by weakening the standard assumption of having the steady-state control input generated by a linear system.

A dissipativity-based approach to output regulation of non-minimum-phase systems

Abstract The present paper presents a new contribution to the design of output regulators for a class of nonlinear systems characterized by a possibly unstable zero dynamics. It is shown that the problem in question can be reduced to a stabilization problem, with a supplementary “gain constraint”, for a suitably defined reduced auxiliary plant.

Network aspects relevant to the integration between the GSM network and a satellite system

The integration between cellular and satellite systems permits to provide wider and more efficient area coverage. In this paper the viability of a full integration between the GSM cellular network and a spot-beam satellite system is dealt with. The integration analysis focuses on the network aspects. Full integration means to reuse, as far as possible, the same equipment and protocols, i.e. the same hardware and software, for the satellite and the GSM network. In the integrated system the user need not be aware whether the actual connection goes through the satellite or the GSM network. The paper identifies the most promising satellite system configuration and the satellite system counterpart of the GSM functional areas (cell, location area, MSC area). Moreover, the problems and the relevant solutions related to the extension of the GSM procedures (e.g. call set-up, cell selection/reselection, handover, initial acquisition, tracking) to the satellite system are dealt with.The integration between cellular and satellite systems permits to provide wider and more efficient area coverage. In this paper the viability of a full integration between the GSM cellular network and a spot-beam satellite system is dealt with. The integration analysis focuses on the network aspects. Full integration means to reuse, as far as possible, the same equipment and protocols, i.e. the same hardware and software, for the satellite and the GSM network. In the integrated system the user need not be aware whether the actual connection goes through the satellite or the GSM network. The paper identifies the most promising satellite system configuration and the satellite system counterpart of the GSM functional areas (cell, location area, MSC area). Moreover, the problems and the relevant solutions related to the extension of the GSM procedures (e.g. call set-up, cell selection/reselection, handover, initial acquisition, tracking) to the satellite system are dealt with.

Quality of Experience Provision in the Future Internet

This work deals with the satisfaction of the quality of experience (QoE) requirements in the perspective of the emerging future Internet framework. The evolution of the Internet is pointing out its limitations, which are likely to hinder its potential. In this respect, this paper introduces an innovative approach to cope with some key limitations of the present communication networks. In particular, the need of efficiently utilizing the available network resources and of guaranteeing the user expectations in terms of QoE requires a full cognitive approach, which is realized by the introduction of a novel architecture design, the so-called future Internet core platform. The future Internet core platform aims at bringing together the applications world with the network world, hence introducing a further cognitive level while enabling a new generation of applications: network-aware applications. This paper is concerned with an important aspect of the intelligent connectivity between applications and network: the service class association, which, if performed with a cognitive approach, can yield some important improvements and advantages in the emerging information era. The key idea presented in this paper is a real-time dynamic control procedure for the selection of the optimal service class. The approach is based on theoretical considerations validated by a proof-of-concept simulation.

An optimal approach to the connection admission control problem

The paper considers the connection admission control (CAC), which is a key resource management procedure, and proposes a solution to the problem based on modelling and control methodologies. The CAC problem will be formulated as an optimal control problem subject to a set of constraints. As a matter of fact, the proposed controller, modelling the CAC mechanism, computes the above-mentioned control variables so that (i) a set of proper constraints, which model the quality of service (QoS) requirements (link availability, blocking probability and dropping probability), are respected and (ii) a proper performance index, which models the exploitation degree of the available bandwidth, is maximized. The proposed CAC successfully compares with other CACs proposed in the literature, and in particular significantly extends the upper limit of the accepted traffic rate.

A Future Internet oriented user centric extended intelligent transportation system

Intelligent Transportation Systems (ITS) are changing the way people plan a journey and travel around the world. Advanced mobility information systems, as well as intelligent multimodal mobility services, may take considerable advantage of consolidated technologies from emerging ICT frameworks. In this paper we propose an Extended Intelligent Transportation System (ExITS) consisting of a basic ITS equipped with a User Centric Control System (UCCS). The proposed ExITS relies on service personalization methodologies and is conceived as a Future Internet (FI) oriented, closed-loop, user centric architecture integrating and controlling ITS services. The proposed UCCS considers the trip planning service and takes into account both explicit and implicit user preferences in selecting travel solutions satisfying a given user request. The aim of the UCCS is to drive the trip planning service in proposing to the user travel typologies tailored to personal preferences. Implicit preferences are automatically inducted by similarity based unsupervised machine learning techniques and verified by a closed-loop control mechanism triggered by explicit user feedback.

Joined MAC Scheduling and Transport Format Choice for UMTS Uplink Transmission

This paper deals with the description of the QoS architecture developed in the framework of the IST VIRTUOUS and SAILOR projects, especially targeting at the design of an UMTS MAC scheduling algorithm in charge of managing several uplink parallel active logical channels at User Equipment side. The joined approach to the packet scheduling and transport format choice proposed in this paper shows better performances respect to the 3GPP standard solution, mainly when the number of logical channels of different types – i.e. logical channels with different needs in terms of maximum allowed delay – handled by the same User Equipment increases. Furthermore, the proposed MAC design introduced in this paper allows a better exploitation of the available bandwidth in the uplink UMTS Radio Access Network, also increasing fairness between IP datagrams belonging to different sources.

Traffic management in a band limited communication network: an optimal control approach

This paper focuses on the scheduling and congestion control problems for a band limited communication network, taking into account the QoS requirements of the various connections. The problem is tackled and solved using optimal control methodologies. The optimal solution is given a closed form representation and is characterized by the classical closed loop structure. Applications against simulated realistic data show the improvements achievable by the proposed approach.