Upon further research, i realized that this is not a possibility:
“Frankly, you don't. Native push notifications require the use of the GCM servers in the internet. Most customers allow SMP / Afaria to connect to the notification servers GCM, APNS etc and open their WiFi infrastructure in a way to give the devices also access to those servers. You should be able to nail down the ports and traffic using your firewalls etc to prevent stuff from going through that is are not notifications.
Use devices that do not have an internet based notification system (e.g WindowsMobile, WinCE) ;-)
Build a notification system on IP base - e.g. have your app poll your server regularly for new items. Problem: Battery life will go bad on you as the app needs to be active a lot more and consumes much more battery this way. This is the exact reason, why the notification systems exist - the OS can receive notifications much more efficient as any app running in a sandbox could.
Under the line it is a take-it or leave-it situation. A simple fact of modern mobile life that you can love or hate :-)
“No, it is not possible to send push notifications without using the Browser Cloud Managers. Remember the Browsers implement Push API , as per the W3 Push API standard . This is what made Web Push notifications possible on Desktop and Mobile browsers.
At the time of subscription these API’s provide you a subscription token, and the Browser Cloud Manager (FCM for Chrome etc.) are the only one who maintain the mapping of which subscriber token maps to which client browser. Hence, you need to use the respective cloud manager for the browsers.
Each browser is different and while they implement the standard, each has its idiosyncrasies, and hence it is often advisable to use a 3rd party vendor (like PushEngage which we run) who has build support for sending notifications on top of all browsers.”