Cisco Wireless Network Architectures

Dears ,

I have a question about CAPWAP tunnel ,what it is exactly purpose ,what i understood from explaination is CAPWAP existed to overcome on the problem of offering user VLANs into switchport where is connected with switch

“How can the lightweight AP offer an SSID that uses VLAN 20 or 30 while it’s connected to a switchport in VLAN 11? That’s what the CAPWAP tunnel is for; it tunnels VLAN 20 and 30 traffic from the lightweight AP to the WLC.”

question is i think it is normal to offer an SSID that uses VLANs 20,30 to be with VLAN11 ,just to let the port where is connected to switch to be member of three VLANs 11,20,30 , this is a way to do without using CAPWAP tunnel , Am i right ?