As part of Android 2.2, the Android cloud message push mechanism has been released. C2DM allows the third-party developers to develop related applications that can push small amount of data message to the user's mobile phones. C2DM has created a good opportunity to allow the use of various Google development tools to create a simple but very useful application type. Users can use applications of that type to push various information from his desktop or laptop directly to their mobile phones. C2DM does not provide any built-in user interface or process other news data. Instead, it is an application that simply passes the original information data; it has complete control over the direct received information. For example, the application may issue a notice, display a customized user interface, or quietly synchronize data. It may need higher Android 2.2, and also has the equipment installed by the application of the market. It uses the existing connection of Google services, which requires the user to create their own Google accounts on their mobile devices. The size of each notification message is limited to 1024 bytes, Google will limit the total number of messages sent, and the number of the messages is sent to a specific device. This system provides a library package of the C2DM, which allows developers to easily use the C2DM function. C2DM can achieve the push mechanism from server to mobile client server, rather than the traditional pull data mode. Push mechanism allows the phone to be more traffic efficient and power efficient. Mobile client server first applies the registration code from C2DM server, then send the registration code to a third-party server. The third-party server will send the message that need to be pushed to a Google server, and then the necessary information will be sent by a Google server to a mobile client server.
