Monitoring, Management & Location Tracking

Environment : Aruba OS 6.3 and above.

Yes, heartbeats are exchanged between the license server and the license clients on every 30sec. The license heartbeat is sent using PAPI and this will carry the licensing information.
 
The license client initiates the heartbeat message with the license counts to the license server.  The license server adds all the license counts from each client, then sends the total counts to the clients in the heartbeat response message.
 
(Master) #show license heartbeat stats
 
License Heartbeat Table
-----------------------
Client IP Address   HB Req      HB Resp     Total Missed  Last Update (secs. ago)
-----------------           ------       -------           ------------     -----------------------
192.168.1.4              224         224                      0             6
192.168.1.5              224         224                      0             0
192.168.1.3              226         226                      0             26
192.168.1.2              227         227                      0             6