How to extend WiFi coverage of mikrotik hotspot + radius ?

RouterOS Wireless Networking
1

Dear all,
I have this scenario:

  1. A central switch and two mikrotik access point connected to it through ethernet that cover all my environment. Both access point are configured in ap-bridge mode with same SSID and both access point have a bridge that include ether interface (the interface that connect them to central switch) and wlan interface. In this scenario I simply want to extend my cabled network.

  2. I would to implement with the same access point a separate network only for guest. Then I created a virtual wlan interface for each router and configured for them hotspot funcionality with only one radius server installed on one of access point. The other access point send authentication request to the first access point that have user manager. All run correctly. The issue I would to solve is this one:

When a user authenticate to one access point and then move with his device to coverage of other access point obviously it ask newly for the authentication. In which way Can i solve this issue? I would that only one time the authtentication is required and user can move from access point to another transparently

thanks in advance