Can the device be controlled via Wi-Fi?

Question

Computer networks

Hello!
There are technical specifications, but there are also implementation questions:
1. The principle of Wi-Fi on android / ios devices - if at one point there are several wifi networks to which the phone / tablet knows the password (some further, others closer), which network the device will connect to - which is closer or at your discretion (in the background)!
2. There is Wi-Fi in the metro, McDucks, self-service car washes, and when connected to the network, a site for authorization opens. How to implement and supplement this - open the alarm clock application (like Alice and Google Assistant) or turn on sound (or video) playback ?!
3. At a certain time, completely block access to the Internet, only internal addresses are allowed.
How to implement everything?!
Thank you all in advance for your replies!!!

Answer 1

1. The principle of Wi-Fi on android / ios devices - if at one point there are several wifi networks to which the phone / tablet knows the password (some are further, others are closer), which network the device will connect to - which is closer or at its discretion (in the background mode)!

The client connects to the network with the highest signal or uses a user-defined priority. To connect automatically, you need to connect to this network at least once, or specify on the client - connects to unsecured networks automatically.
This is implemented using CAPTIVEPORTAL.

3. At a certain time, completely block access to the Internet, only internal addresses are allowed.
How to implement everything?!

The implementation can be both on the access point and on the WIFI controller, and on the server that releases to the Internet. Read the specification for the equipment you will be using.