indicated in block 46 while this is occurring the receiver monitors station id signals received through its digital channels to determine when a cell boundary has been crossed block 47 and detection function 48 as explained earlier the receiver detects boundary transitions by comparing id signals or other signals received from the nearest transmission towers and determining when the signal currently used to establish the reception frequencies modes is weaker than one coming from another transmission source when the crossing is detected the database is checked for the new frequency or mode associated with the now stronger signal switches the reception to that frequency or mode block 49 and continues seamlessly to continue playing the program material that was playing before the crossing block 46 fig5 shows how presently contemplated receivers can be operated to interleave and play analog and digital program segments that are transmitted intermittently and either concurrently or time staggered in relation to each other assume the receiver has been powered on block 44 and the user has selected a virtual station that is broadcasting locally in this mode block 54 assume further that the receiver is instantly playing a program segment defined by digital signals block 55 at this time the receiver monitors received control signals block 56 for a signal representing an insertion time indicator that preferably is sent in digital form but could be sent in analog form and still produce the effects described next on detection of this indicator the receiver 39 s digital section examines a stored database of local setting information block 57 and uses that setting information.