WCF/WF - pushing operation

For your requirement you have to consider using Duplex Binding:

http://msdn.microsoft.com/en-us/library/ms731064.aspx

Here is a short walkthrough on how to use the Duplex binding to send messages from server.

http://geekswithblogs.net/claeyskurt/archive/2007/09/05/115169.aspx

 I hope, This will help you to push data to client.

Regards,

Sam.

You need to implement your WCF service with Duplex behavior with "wsDualHttpBinding" as binding type.

& you need to specify "CallbackContract" attribute to your defined interface.

More help please refer MSDN

Let me know if you need any help for implementation