Specific to Samsung Note 3 only

What are the red/green arrows in the notification bar on my Samsung GALAXY Note 3?
The red/green arrows appear on Samsung GALAXY Note 3 means that you can make HD phone calls on 4G Network on your Samsung GALAXY Note 3 at no additional cost. Samsung Note 3 handset is the 1st handset in the world to be able to support voice on LTE (VOLTE).
What is the supported and unsupported Build numbers for Note 3?
Supported VoLTE and latest software: KOT49H.N9005DXUENE4
Unsupported VoLTE software: N9005DXUENF6
(All future software updates for Note 3 can support VoLTE.)
I bought a Samsung Note 3 from 3rd party providers or StarHub/M1, can I enjoy this service?
No, your software build no will not be upgraded to support VoLTE. If the device is from other operator, it may show the same Build Number but still not supporting VoLTE.