Transfer 3 interface with 1 antenna.

Hi I have setup a mini ISP where all my machines are located in my place
Load balancer router switch server.
I want to have 2 or 3 modems to another location and transfer them to my place with I antenna.
How can I do it I need another load balancer or the simplest another antena.

Or create 2 or 3 vlans tag them transfer them with 1 antena and untaged them to my place. Is it possible?

so this is my setup after the load balance everything works fine.
but will vlans15 16 17 transfer lke this and alsow will vlan 23 travel back to the source so it wil be after pppoe


https://www.dropbox.com/s/jchm20cviehhug1/φωτογραφία.JPG