1. Fig-1 depicts the exising Internet and WiFi-LAN (Local Area Network) in my home cosisting of:
Figure-1:
(1) Three PCs with WiFi (Wireless Fidelity) devices/connectivity.
(2) Four Mobile Phones with WiFi devices.
(3) WiFi Router which is connected with Internet Modem by physical cable. In many cases, Modem and Router appear as a single unit; where, the word Router is used to refer to the whole unit.
(4) Internet Modem which is connected with my ISP Provider's Server by Optical Fibre.
(5) 30-pin ESP32 Dev Module which works as a Web Server and passes the "Close Condition of K1" to Mobile-1 via WiFi Network.
2. How do ESP32 and Mobile-1 communicate each other in a Router based WiFi Network?
(1) The ISP Provider (Internet Service Provider) assigns a Public IP (Internet Protocol) Address for the Router. For my Router, the IP Address is: 192.168.0.105.
(2) The ISP Provider also assigns the following credentials (changeable bythe user) for the Router:
SSID (Service Set Indentifier): "SiamWifiNew"
Password (Pass Word): "siam1234"
(3) The Router broadcasts a 2.4 GHz WiFi signal which can be detected by ESP32 and Mobile-1 and join with the network using Router's credentials mentioned above.
(4) The Router assigns "Private IP Address" to ESP32 (we will see later) and Mobile-1 which they use during mutual communication via Router.
3. How to pass the "Close Condition of K1" of ESP32 to Mobile-1.
...pending