A method of generating a model of a cellular communication system comprises generating (101) a first cell layout for a first area and then generating (103) a displaced set of cell layouts corresponding to the first cell layout displaced in a different directions such that it borders the first cell layout. A unique mapping exists between the cells of the first set and of the displaced sets. A model location set is generated (105) comprising a plurality of locations within the first area. For each location and for the cells of the first cell layout, the method comprises evaluating (111) an interference characteristic for cells of a cell group containing all the corresponding cells in the different cell layouts. A cell is then selected (113) from the cell group as an interfering cell for the location. The resulting model provides improved wrap around performance while achieving low computational burden for performance evaluation based on the model.
