Android Cloud to Device Messaging
To use C2DM on your Android device you have to write an Android application. This application will register at a Google server to be able to receive push messages from the Google server. Your server registers with the Google server and authenticates himself. The server can then push messages to the Google server which in return pushes the information to the device. For this authentication you require a Google user.
Characteristics of Android Cloud to Device Messaging (C2DM):
* Android Cloud to Device Messaging allows third-party application servers to send lightweight messages to their Android applications. The messaging service is not designed for sending a lot of user content via the messages. Rather, it should be used to tell the application that there is new data on the server, so that the application can fetch it.
* C2DM makes no guarantees about delivery or the order of messages. So, for example, while you might use this feature to tell an instant messaging application that the user has new messages, but you may not use it to pass the actual messages.
* An application on an Android device doesn’t need to be running to receive messages. The system will wake up the application via Intent broadcast when the message arrives, as long as the application asset up with the proper broadcast receiver and permissions.
* Android Cloud to Device Messaging does not provide any built-in user interface or other handling for message data. C2DM simply passes raw message data received straight to the application, which has full control of how to handle it. For example, the application might post a notification, display a custom user interface, or silently sync data.
* Android Cloud to Device Messaging requires devices running Android 2.2 or higher that also have the Market application installed. However, you are not limited to deploying your applications through Market.
* Android Cloud to Device Messaging uses an existing connection for Google services. This requires users to set up their Google account on their mobile devices.