Anytime frequency allocation with soft constraints

Abstract

As is well known, the frequency allocation problem for mobile telephone networks can be approximated by a graph coloring problem where vertices model transmitters, colors model frequencies, and an edge corresponds to a pair of transmitters that must not use the same frequency. However, the graph coloring analogy doesn't suffice for modeling real world problems, which involve soft constraints and general distance constraints. Thus, general constraint satisfaction techniques are called for. In this paper, we model the frequency allocation problem as a partial constraint satisfaction problem, and give a branch & bound algorithm for solving it. We review a number of constraint solving techniques used in this problem and discuss their relevance to performance