The efficient use of bandwidth for radio communications becomes more and more
crucial when developing new information technologies and their applications.
The core issues are addressed by the so-called Frequency Assignment Problems
(FAP). Our work investigates static FAP, where an attempt is first made to
configure a kernel of links. We study the problem based on the concepts and
techniques of Constraint Programming and integrate the site availability
concept. Numerical simulations conducted on scenarios provided by CELAR are
very promising.