GCM: how to avoid throttling

My android system needs to send frequent updates to an app for tablet (a kiosk always connected to wifi and power plug).
GCM-HTTP (//developer.android.com/google/gcm/http.html) works fine but in some cases it can happen that a single device receives many notifications triggering the well- known throttling issue described here (//developer.android.com/google/gcm/adv.html#throttling). This is a problem since the payload in the notification is of great importance for the system. What is the best solution to prevent this?

implement in the server a service that groups notifications to the same device and shoot them with a limited frequency.
use a XMPP service. I would like to use GCM-XMPP (//developer.android.com/google/gcm/ccs.html) but you need to be signed in a whitelist so I don't think everyone can already use it. As alternatives should I use aSmack or Quickblox as advised here (Android and XMPP: Currently available solutions) and here (Better Way to implement the chat application using XMPP on Android?) respectively?
implement a basic socket connection as described in (//thinkandroid.wordpress.com/2010/03/27/incorporating-socket-programming-into-your-applications/)? In this case I have to take into consideration the possibility of the connection getting momentarily lost?

SOLUTION: I found the solution to my question, that is XMPP protocol. At the beginning I implemented aSmack in the tablet application and configured an eJabberd server running locally. The implementation has been pretty easy. After a couple of weeks I received a mail from Google for the GCM-XMPP, that is even quicker to embed in the app and works super fine!

Maybe setting time_to_live to 0.

From http://developer.android.com/google/gcm/adv.html:

"Another advantage of specifying the expiration date for a message is that GCM will never throttle messages with a time_to_live value of 0 seconds. In other words, GCM will guarantee best effort for messages that must be delivered "now or never." Keep in mind that a time_to_live value of 0 means messages that can't be delivered immediately will be discarded. However, because such messages are never stored, this provides the best latency for sending notifications."