These researches are supported by the National MURST Project Cofinanziato 1999 and Cofinanziato 2001 Progetto e Gestione di Reti di Telecomunicazione.
Optimal Location of UMTS Radio Base Stations
In a given a territory to be covered by a mobile communication service a set of potential locations where a base station can be placed are given. The problem under study consists in determining in which locations to install a radio base station and how to set all the parameters of the base stations so that the desired coverage is attained and the global cost is minimized. The research proposes matematical models that consider explicitly the propagation and transmission quality in the case of UMTS (code division). Possible constraints on the electomagnetic pollution can be included. Ad hoc solution algorithm are developed and applied to real cases.
Planning of UMTS systems web site
Slides presentation
Wireless Local Area Network Planning
Wireless Local Access Networks (WLANs) are expected to become pervasive in working environments as well as public areas. They will replace traditional wired local networks indoor and allow flexible access outdoor. Although the small systems currently installed are planned using rules of thumb, their rapid spread and size increase calls for quantitative methods to determine cost efficient solutions with service quality guarantees. A WLAN consists of a set of access points (antennas) each of which is able to serve a subset of users whithin hearing distance. Since a user can access the network only if no other user is simultaneously connected to the same access point or is interfering with it, the network capacity is naturally measured as the sum over all users of their probability of accessing the network. We show that the resulting optimization problems can be seen as extensions of the classical set covering or maximum coverage problems. Since solutions with many access points serving small, possibly non-overlapping, subsets of users, the interactions between selected access points (the corresponding subsets of users), must be accounted for. Different mathematical programming problems, based on quadratic and hyperbolic formulations, are investigated.
Slides presentation 
Joint Routing, Wavelength Assignment and Network Design in All-Optical Networks
A new mathematical model for all-optical network design, including sparse optical cross connects placement, optical routing and wavelength assignment is studied. The proposed integer linear program is refined by introducing valid inequalities, and a cutting plane procedure is described. The solution procedure is implemented using commercial mixed integer programming solvers and applied to some real instances of metropolitan and wide area networks with encouraging results that prove the validity of the approach. A branch and cut algorithm is under development.
Slides presentation
Packet Scheduling with smart antennas
Exploiting beam forming techniques of adaptive antenna arrays
(smart antennas), packet transmissions can be scheduled taking
into account the arrival direction of signals so that the mutual
interference of transmissions in the same time slot can be minimized.
In this paper we
investigate two combinatorial optimization problems arising when
scheduling packets in a smart antenna.
In the first problem, one has to select a subset of users which
can be simultaneously served in a given time slot so as to maximize
the total priority of the users served. An arc-circular model
is proposed together with a polynomial-time algorithm which searches
for a path of maximum total weight in an appropriate graph. In
the second problem, the users must be partitioned into noninterfering
subsets so as to minimize the number of time slots needed to transmit
all the given packets. In this case a lower bound and heuristics
have been devised.
Slides presentation
Collaborators
Edoardo
Amaldi
Pietro Belotti
Lorenzo
Brunetta
Antonio
Capone
Michele Zorzi (Università di Ferrara)
External collaborators
Peter Värbrand (ITN, Linköping University), Di Yuan (ITN, Linköping University), Gunnar Jacobsen (Ericsson Stockholm), Luciano Tarricone (Università di Lecce).
List of papers
