US Patent 10897413 Determining operational status of internet of things devices

Disclosed are various examples for offline detection of Internet of Things (IoT) devices or any type of devices that report a heartbeat or status indication. A linked hash map be utilized as a data structure in which heartbeat message are stored. The oldest heartbeat message is stored at the head of the data structure so that only the head of the data structure requires checking if the oldest node is designated as online.