Abstract: A cellular radio system includes three neighboring cells A3, A2, A1 which each have a number of channels (1 to 13, 14 to 26, 27-39 respectively) allocated for their use. A microcell M contained within cell A1 is served by a separate base station. The microcell has available to it channels 1 to 6 and 21 to 26 from the allocations of neighboring cells A2 and A3. The base stations A2, A3 and M are controlled such that no channel is in use simultaneously in both the microcell M and cell A2 or A3. This arrangement allows channels to be reallocated between neighboring cells according to demand, without reducing the peak capacity in individual cells.

Abstract: A cellular telecommunications network includes spaced apart base stations. Each base station has three directional antennas for transmission and reception of signals to subscriber units. Eight frequency groups are assigned among all the antennas such that each frequency group is reused on average at three out of every eight base stations.

Abstract: A method of computing parasitic capacitances between multiple electrical conductors within an electric circuit computes a division of the circuit's physical layout into a plurality of windows. The parasitic capacitances associated with the conductors of each window are computed, and the results for the various windows combined into a matrix of parasitic capacitances for the overall circuit. The windows are preferably overlapped, with the capacitance values for conductor pairs located in more than one window averaged. Complex polygons are fractured into simpler shapes by extending a ray from a vertex of the polygon to intersect an opposed segment, and defining the peripheries of the simpler elements as comprising the ray and respective different portions of the original polygon's periphery. Rays may be extended in a x,y pattern from multiple vertices of the polygon until a ray is located that extends through the polygon's interior, with the fracturing performed along that ray.