Any idea what these arrows In the notification tab are?

Hi all :)

I had a software update today to android version 5.0 on my S5.... any idea what the two horizontal arrows mean and how / or if I can get rid of them? I did not have them before the update ?

I have read somewhere about the VoLTE (Voice over LTE) is activated but I have checked settings mobile networks and nothing seams to be in there and it all looks the same as before.

Thanks in advance