A method for supply chain monitoring, the method comprising: establishing a communication network, the communication network including a plurality of mobile sensor nodes (12, 12a, 12b, 12c, 12d); periodically transmitting status information for each mobile sensor node (12, 12a, 12b, 12c, 12d); each mobile sensor node (12, 12a, 12b, 12c, 12d) receiving status information for at least one other mobile sensor node (12, 12a, 12b, 12c, 12d) in the communication network; compiling a log file (28, 53), the log file (28, 53) including the received status information; and storing the log file (28, 53) in the mobile sensor node (12, 12a, 12b, 12c, 12d) that received the corresponding status information, wherein at least one of the mobile sensor nodes (12, 12a, 12b, 12c, 12d) operates in a watchman mode, the method further comprising placing the mobile sensor nodes (12, 12a, 12b, 12c, 12d) not operating in a watchman mode in a sleep mode characterized in that the watchman mode comprises: operating in a standby mode to receive the status information from the at least one mobile sensor node (12, 12a, 12b, 12c, 12d); and determining whether a mobile sensor node (12, 12a, 12b, 12c, 12d) is in an alarm condition based on the received status information, wherein responsive to determining that a mobile sensor node (12, 12a, 12b, 12c, 12d) is in an alarm condition, the watchman mode further comprises: waking all other mobile sensor nodes (12, 12a, 12b, 12c, 12d) of the communication network from sleep mode; and transmitting a notification of the alarm condition. establishing a communication network, the communication network including a plurality of mobile sensor nodes (12, 12a, 12b, 12c, 12d); periodically transmitting status information for each mobile sensor node (12, 12a, 12b, 12c, 12d); each mobile sensor node (12, 12a, 12b, 12c, 12d) receiving status information for at least one other mobile sensor node (12, 12a, 12b, 12c, 12d) in the communication network; compiling a log file (28, 53), the log file (28, 53) including the received status information; and storing the log file (28, 53) in the mobile sensor node (12, 12a, 12b, 12c, 12d) that received the corresponding status information, wherein at least one of the mobile sensor nodes (12, 12a, 12b, 12c, 12d) operates in a watchman mode, the method further comprising placing the mobile sensor nodes (12, 12a, 12b, 12c, 12d) not operating in a watchman mode in a sleep mode characterized in that the watchman mode comprises: operating in a standby mode to receive the status information from the at least one mobile sensor node (12, 12a, 12b, 12c, 12d); and determining whether a mobile sensor node (12, 12a, 12b, 12c, 12d) is in an alarm condition based on the received status information, wherein responsive to determining that a mobile sensor node (12, 12a, 12b, 12c, 12d) is in an alarm condition, the watchman mode further comprises: waking all other mobile sensor nodes (12, 12a, 12b, 12c, 12d) of the communication network from sleep mode; and transmitting a notification of the alarm condition. operating in a standby mode to receive the status information from the at least one mobile sensor node (12, 12a, 12b, 12c, 12d); and determining whether a mobile sensor node (12, 12a, 12b, 12c, 12d) is in an alarm condition based on the received status information, wherein responsive to determining that a mobile sensor node (12, 12a, 12b, 12c, 12d) is in an alarm condition, the watchman mode further comprises: waking all other mobile sensor nodes (12, 12a, 12b, 12c, 12d) of the communication network from sleep mode; and transmitting a notification of the alarm condition. waking all other mobile sensor nodes (12, 12a, 12b, 12c, 12d) of the communication network from sleep mode; and transmitting a notification of the alarm condition.