Ember, inject a service application wide

I know this question is already posted but i don't find any updated or well explained response.

So i have a service "session" & "current-user" who have my session & current user (obvious) in memory and i need to have this service in every controllers, actually, in every controller i do

session: service(),
currentUser: service('current-user'),

My question is, how to make those services available in all controller without redeclare them in every controllers ?

Thank you.