I am using WCF to write a server that should be able to communicate with .Net clients, Android clients and possibly other types of clients.
The main type of client is a desktop application that will be written in .Net. This client will usually be on the same intranet as the server. It will make an initial call to the server to get the current state of the system and will then receive updates from the server whenever a value changes. These updates are frequent, perhaps once a second.
The Android clients will connect over the Internet. This client is also interested in updates, but it is not as critical as for the desktop client so a (less frequent) polling scenario might be acceptable.
All clients will have to login to use the services, and when connecting over the Internet the connection should be secure.
I am familiar with WCF but I am not sure what bindings are most appropriate for the scenario and what security solution to use. Also, I have not used Android, but I would like to make it as simple as possible for the person implementing the Android client to consume my services. So, what is my strategy?