Signal integrity on a set from three to eight lossy copper interconnects of less than one square micron is determined from a transient simulation based on electrical circuit representation. This circuit is deduced from a full wave finite element method. Our signal integrity results on numerous possible excitations show that two neighbour interconnects on both sides of a reference aggressor or victim is sufficient to predict more complex situation on largest number of wires. This means that the five interconnects case is also well appropriate. We have verified that it is the best compromise whatever the permittivity of dielectric material which filled the spacing between interconnects, as well as the width of this spacing.