A sheet punching and embossing machine has a gripper carriage and a positioning device for the gripper carriage. quality-controlled, pulsed solid-state laser is used. Sticky determination logic is also provided for determining from a second set of bits of each of the pair of 2n-bit vectors a sticky value, and selector logic is then used to derive the n-bit result from the output of the sum logic with reference to the sticky value. Duty ratio of the pulse DC voltage is set to not less than 20% and not more than 90%. The method comprises, when a priority call is in progress in the serving cell, performing at least one of preventing at least one non-priority call from being handed over into the serving cell and preventing at least one non-priority call from being initiated in the serving cell.