Can I use Duplex WCF services with Xamarin.Forms.

When I try to use PUB/SUB model with xamarin forms using duplex wcf service I get an exception for android and IOS projects.

Android Exception: System.ServiceModel.Duplex.dll not found. Perhaps it doesn't exist in Mono for android profile.
IOS: MT2002 Failed to resolve assembly " System.Security".

I am using Xamarin.Forms.PCL to share the code and populate UI. I am trying to subscribe to a publisher and get notifications. Basically trying to implement PUSH notifications in Xamarin Forms