Push Notifications without "Firebase Cloud messaging API"

Hi, is possible use Push Notification without “Firebase Cloud messaging API”, I will working with aspx (WCF). someone can give me some material about this theme.

I have this version installed
Ionic Framework Version: 3.0.1
Ionic CLI Version: 2.2.2
Ionic App Lib Version: 2.2.1
Ionic App Scripts Version: 1.3.0
ios-deploy version: Not installed
ios-sim version: Not installed
OS: Windows 7
Node Version: v7.9.0
Xcode version: Not installed

Yes, you can use any other push provider. You will probably have to touch FCM to generate keys and stuff as this is the platform to send pushes to Android devices (that succeeded GCM that was used earlier) but you don’t have to use the API and their libraries. There are many other providers, including Ionic Services itself with Ionic Push.