Patent ID: 11949746
Assignee: KOREA ELECTRONICS TECHNOLOGY INSTITUTE
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 3:
4. An Internet of things (IoT) communication method by an IoT device connected with a server via a network address translation (NAT), the method comprising:
connecting to the server via the NAT;
executing a first session for service connection;
when a communication unit connects to a new network, identifying whether a specific keep alive value corresponding to a corresponding network environment is stored in the server;
when the specific keep alive value is stored, setting the communication unit to communicate with the corresponding specific keep alive value;
when the specific keep alive value is not stored in the server, executing a second session for calculating a specific keep alive value corresponding to a period in which an IP address mapped by the NAT expires;
controlling the communication unit to transmit a first time value to the server in the second session;
identifying whether a response is received from the server after a time corresponding to the first time value is elapsed;
when the response is received, increasing the first time value by a unit time and iteratively retransmitting the increased first time value to the server;
when the response is not received, setting a time value which is the unit time subtracted from the corresponding first time value as a specific keep alive value of the first session;
finishing the second session; and
transmitting a connection IP address, connection environment information, device information for calculating the specific keep alive value, and the calculated specific keep alive value to the server,
wherein the specific keep alive value corresponds to a maximum value of a time during which the IP address is maintained without being changed.