DirectPush

AUTDv2 is Directpush. Directpush can be simply thought of delyed response to the request. The mobile client submits request to the Exchange server with the following two significant request parameters.

1. Timeout - let us consider X duration

2. Folder list - The list of Exchange folders the server should watch on

After receving the request, the exhange server looks for changes in the folders. If there are changes in the folder before X duration elapsed, the server returns the changes to the client and the client updates the changes to its local inbox.  If there are no changes for X duration, the server simply returns and inform the client that there are no changes. If the client receives no changes from the server, the client once again send the request to the server with same request parameters and this loop goes on.

Some people do not accept this as push model. However our requirement of keeping the client inbox Uptodate is solved. If your device is in hybernation mode and there are incoming data from the server, the GPRS radio wakes up the client and the device process the packets. Connection is maintained when device is hybernated. Technically Direct push works over any network interface that supports TCP/IP. Windows mobile imposed a limitation with WiFi because most WiFi interfaces are not able to do the "wake-on-receive" that GPRS radio does.