Method of monitoring, information processing apparatus, and communication apparatus

An information processing apparatus comprising:

• a memory;
• and
• a processor coupled to the memory and configured to:
• transmit a polling signal to a first communication apparatus;
• receive, from the first communication apparatus, information on a first notification target which is detected in the first communication apparatus and first interval information indicative of a difference between timing at which the first notification item is detected and timing at which the polling signal is received in the first communication apparatus;
• and
• determine, based on first time information indicative of timing at which polling is performed and the first interval information, a time sequence of the first notification target and a second notification target which is detected in a second communication apparatus.

A communication apparatus comprising:

• a memory;
• and
• a processor coupled to the memory and configured to:
• receive a polling signal from a transmission apparatus which collects a notification target;
• calculate a difference between timing at which the notification target is detected and timing at which the polling signal is received;
• generate a response signal including interval information indicative of the difference and information on the notification target;
• and
• transmit the response signal to the transmission apparatus.