SYSTEM AND METHOD FOR CELLULAR CALL MONITORING USING DOWNLINK CHANNEL CORRELATION

摘要

Methods and systems for monitoring communication of mobile communication terminals, such as cellular phones. An off-air monitoring system reconstructs both directions of a call conducted between two mobile terminals by receiving only downlink channels. The off-air monitoring system receives multiple downlink transmissions transmitted by base stations in a wireless communication network. The system uses the received downlink transmissions to reconstruct the bidirectional call content of calls conducted between wireless terminals. In order to reconstruct the bidirectional content of a given call, the system identifies and correlates the two downlink transmissions of that call from among the multiple received downlink transmissions.

主权项

1. A method for reconstructing bidirectional call content of calls conducted between wireless communication terminals, the method being exclusively based on downlink transmissions without a need to receive any uplink channels, the method comprising:
receiving, by a monitoring system, multiple downlink transmissions that have been or are being transmitted from at least one base station or satellite of at least one wireless communication network to wireless communication terminals of the at least one wireless communication network; identifying, by the monitoring system, among the multiple downlink transmissions, a pair of first and second downlink transmissions that carry respective first and second opposite directions of a given terminal-to-terminal call, wherein the monitoring system has no prior identification of pairs of downlink transmissions; and reconstructing, by the monitoring system, a bidirectional content of the given call from the identified first and second downlink transmissions.