Apps Android notifications

[manishsawant]

Hi,

We are in the process of creating an app for smartphones and i am new to this. I would like to understand how the notification option works in these phones. I have the below questions.

1. Can we sent notification even if the user has not logged into the app.
2. How many characters does notification support. Can all the characters be shown in the notification section or they will be reduced and displayed with a ... at the end.
3. Are notification stored in the device.
4. Can we consider notification as replacement over SMS (to save cost of course).
5. If 3 notifications are sent at a time then only the last one will be visible in the notification section or all the 3.
6. Are the noficiations sent from the central server, i would like to know the architecture.

Please share web sites where i can get more information about notifications.