Improving efficiency in frequency assignment engines

The electromagnetic spectrum is a limited resource which is rapidly becoming saturated, and with the trend to charge users, efficient use is critical. Military users must react to different allotments and adapt to the prevailing conditions. The objective of using available bandwidth efficiently, while, at the same time, minimising interference, gives rise to a number of variations of a problem usually referred to as the frequency assignment problem (FAP). Many algorithms have been developed in order to produce optimal or near optimal assignments of frequencies to defined sets of transmitters, but it is recognised that rigorous solutions are only possible for a very small population. Early assignment algorithms were limited in their application, constrained by the available processing speed and thus only considered a reduced set of constraints. The authors have developed a system for combat net radio that takes into account these extensions to the standard FAP It was concluded that the most effective algorithms start from a sequential solution and use a meta-heuristic algorithm such as tabu search or simulated annealing to find solutions for large network deployments.