1. A method of operating a wireless communication system that serves a plurality of wireless communication devices, the method comprising: in a first wireless communication network, exchanging data with ones of the wireless communication devices that are in active-mode on the first wireless communication network and generating corresponding active-mode event records characterizing the data exchanges; in a second wireless communication network, receiving registration messages transferred by ones of the wireless communication devices that are in idle-mode on the second wireless communication network and generating corresponding idle-mode event records characterizing the idle-mode registrations; and in a data processing system, integrating the active-mode event records and the idle-mode event records into integrated communication data records that correlate the active-mode event records and the idle-mode event records by their corresponding event times.