Here are some good posts on grounding:
viewtopic.php?f=30&t=188#p483
http://forum.netonix.com/viewtopic.php?f=30&t=1816
http://forum.netonix.com/viewtopic.php?f=30&t=1429
http://forum.netonix.com/viewtopic.php? ... =30#p13447
https://community.ubnt.com/t5/airFiber/ ... rue#M31070
From your radio/antenna you need a shorter heavier copper ground path with less resistance to Earth Ground than the Ethernet cables. This is another reason why you use a service loop in your Ethernet cables to insure the Ethernet cable path is longer than the ground wire path to Earth Ground.
Since UBNT bonds DC negative to the Earth Ground inside the radio which allows the Rocket to gain access to the Tower Earth Ground through the SMA Jumper to the antenna and thus its mounting clam shells.
So I run a #2 up the tower to an isolated ground bus then #6 with Crimp lugs to to each antenna mount and clamshell bolts.
One might asks why is the bus insulated from the tower, well because if there is a charge on that part of the tower you want as much current as possible to flow down the poor path of the tower steel and only the charge that is around your antenna to jump on your dedicated Earth Ground superhighway. Remember the more current flowing on a wire increases its resistance.