Subspace approach to channel assignment in mobile communication networks

The problem of planning a mobile cellular radio network involves the allocation of channels to base stations so as to ensure that the network can carry sufficient traffic while avoiding interference conflicts. An optimum algorithm for this purpose would meet these constraints while allocating a minimum number of radio channels. The mathematical formulation of this problem reveals that it is a nondeterministic complete polynomial for which the time to solve scales exponentially with its size. The authors extend a technique previously used to address the travelling salesman problem. A method of solution is developed which analytically determines a valid subspace in which solutions must lie before an energy minimisation argument is applied. This approach is shown to simplify the solution technique and guarantees the traffic demand constraints are enforced.