In a communications network that provides services to a plurality of users, events occurring during service processing are accumulated in an event record and sent to a record processor to perform post-processing, such as assessing charges to be billed to users of the network. The method comprises transmitting, to a number of user equipments, a plurality of reference signals, where each signal is beamformed in a distinct direction within at least one correlated domain. An alteration system alters a peak-to-peak level of a synchronizing-signal component of the video signal. Further, the wavelength of the pump signal is selected so that the stimulated scattering causes emission of a signal shifted in wavelength to be substantially equal to the wavelength of the optical input signal. , using the heat transfer element; and forming a fluid communicating graft between an arterial blood supply and the coronary artery.