Android Question Connectivity Advise - best practice

[Declan]

My application is a "Kiosk" type of application that is "TaskLocked" and the "Device Owner".
The user cannot access any other applications on the device.
The application makes extensive use of RDC connections to a MySQL database on the server to pull information. This by either a WiFi or 3G/LTE connection.
It is also a requirement for the server to push messages to the devices.
My questions are:
What would be the best practice for pushing messages from the server to the devices?
I have looked at WebSocket Client Library and this looks like a possible solution.
If the devices are WebSocket Clients, would the server be able to push a message to an individual device or a group of devices - possible using the IMEI number as an unique identifier?

 

[Erel]

As you are already using a B4J server then WebSockets is a good solution. Check this example: Custom WebSocket Based Push Framework
You have full control over the messages and you can send to any device or group of connected device.

If the devices are connected to the internet then you can use Firebase to send notifications. It is simple to configure.