Methods and systems are described for monitoring an activity of a person using a hierarchical node network having at least an ID node, a master node, and a server. The ID node is associated with a person, can monitor the person's activity, can communicate directly with the master node but is unable to directly communicate with the server. The master node can directly communicate with the server and separately communicate with the ID node. The master node associates with the ID node upon detecting a signal broadcast from the ID node. The server determines a location of the ID node. The ID node detects an actionable event related to the person's activity based upon the ID node location, and transmits a message to the master node reporting the actionable event. The master node notifies the server about the event. The server initiates a responsive action based upon the notification.