In this domain total field is written in terms of Bessel and Hankel function solutions to the cylindrical Helmholtz equation.
SMM method formulation, finally helps compute these coefficients of the cylindrical harmonic functions within the cylinder and outside it, at the same time satisfying EM boundary conditions.
Finally, SMM accuracy can be increased by adding (removing) cylindrical harmonic terms used to model the scattered fields.
For N-cylinders, each scattered field modeled using 2M+1 harmonic terms, SMM requires to solve a N(2M + 1) system of equations.
Hence, it is guaranteed to be accurate within limits of model, and not show spurious effects of numerical dispersion arising in other techniques like Finite-difference time-domain (FDTD) method.