Initial-state QED corrections to four-fermion production in e+e- collisions at LEP200 and beyond

The implementation of QED initial-state radiative corrections in the process of four-fermion production at LEP200 and higher-energy e+e- colliders is discussed. Because of the presence of charged-current processes, this is a nontrivial problem, and we compare our approach with other existing treatments. We describe the Monte Carlo algorithm used for the generation of 4-fermion events with photon bremsstrahlung. Comparison between our event generator and semi-numerical calculations are presented, as well as predictions for W and Z pair related cross sections.