A system and method for monitoring a cargo container. The novel system (100) includes a sensor module (10) mounted in each target area (20) and a central monitoring system (40). Each sensor module (10) includes one or more sensors (22) and a transceiver (28) for transmitting data from the sensors to the central monitoring system (40). The central monitoring system (40) includes a transceiver (44) for receiving the data from all sensor modules (10) and a local master processor (46) for processing and analyzing the data. In the preferred embodiment, each transceiver (28) is capable of receiving and retransmitting signals of other sensor modules to relay signals of a particular sensor module (10) in a daisy chain fashion to and from the central monitoring system (40).