Synchronise two wireless cards giving them the same mac address

What I meant is that I am trying to implement a system that uses two wireless cards to enable a user to move from one access point to another without droping the call because the handover should take a maximum of 50ms (miliseconds), that is why in this approach two cards were use so while one is scanning for new access point the second one will still communicate in oreder for the call not to be drop and this action will keep going anytime where there is a need ofhandover

What problem are you trying to solve? VOIP software should handle interruptions of more than several seconds, and I am unsure how you are going to dynamically change the Windows routing table to meet your hand-off goal.