The Apple Push Notification Service is a service created by Apple Inc. that was launched together with iOS 3.0.APNS is used together with Mac OS X Lion Server to push update notifications to clients that have registered to receive updates via a configuration profile and are also using the server's mail, calendar and contacts services. This means that devices such as the iPhone and applications like iCal on the Mac can receive a notification

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The desired behavior, is for the arrival of a push notification to trigger a background download so that when the user next opens the app (either by tapping on the notification, or by opening the app normally), that data is already there.