at least one other gateway device according to any one of the above embodiments (refer to FIG. 11); and

at least one mobile terminal according to any one of the above embodiments.

In one or more embodiments of the present disclosure, referring to FIG. 5, an Internet of Things system of the mobile terminal includes a mobile terminal (SmartCard), a gateway (GateWay), an IOT platform, a middleground, and a web server. The mobile terminal is mainly responsible for receiving information, displaying the information by an EPD, obtaining alarm and locating information, uploading the alarm and locating information to the server via the gateway, and implementing operations of a user such as screen swiping. The gateway is mainly responsible for information transmission between the mobile terminal and the server. Each gateway may correspond to multiple mobile terminals, but each mobile terminal can only join a network from one gateway. The mobile terminal and the gateway communicate with each other in a mode of Long Range Radio (LoRa) or FSK (Sx1278 chip may be used). Information of the mobile terminal and information of the server are both forwarded via the IOT platform and the middleground.

FIG. 2 illustrates a schematic diagram of broadcast frames sent by a gateway before and after network disconnection when a mobile terminal rejoins a network in one or more embodiments of the present disclosure. The broadcast frame sent at the moment t3 is a temporary supplementary broadcast frame.