Send push notifications from server with FCM

Question

Recently I asked a question on sending push notifications using GCM: Send push notifications to Android. Now that there is FCM, I am wondering how different it would be from

Answer 1

This is coming straight from Google

You won’t need to make any server-side protocol changes for the upgrade. The service protocol has not changed. However, note that all new server enhancements will be documented in FCM server documentation.

And from receiving messages it seams there is only some places where its only slightly different. Mainly deleting somethings.

And the FCM server documentation can be found here https://firebase.google.com/docs/cloud-messaging/server