Making the best use of the airways: an important requirement for military communications

The growing communication demands of modern warfare must be met with the fixed resources of the electromagnetic spectrum. When an armed force is deployed, frequencies must be assigned, within a restricted bandwidth and in a short time-scale, to its many (e.g. 400) radios so as to minimise the interference between them. There are too many ways in which a frequency allocation can be made for them all to be evaluated; instead the best assignment that can be discovered within a limited time must be chosen. This is typical of a class of problems known as combinatorial optimisation problems. This paper discusses some of the methods which can be used for solving such problems and presents results for a hybrid algorithm based on construction methods, tabu search and genetic algorithms which has been developed at DERA-Malvern.