Hi

Assuming i have 10 APs MT RB433UAH connected with WDS and OSPF/Static Routes. Ok?

and

The all are connected on 801.11A (54Mbps), ( 3 radios, minipci ) . There are 10 simultaneousness users connected to each AP. What would be the backhaul bandwidth between the last two APs ( 9 and 10 )

Thank you

A network diagram is work a thousand words...

You mention mesh in the subject but not in your post. You need to give a lot more detail on how your network is set up before anyone has a hope of answering your question.