Question

On what basis MAC will provide grant for the Retransmitted PDU when TX side receives NACK for the respective PDU?

If Tx side receives less grant then RLC will Re-segment the RE-TX PDU, but if Tx side receives more grant compare to Re-Tx PDU then how RLC going to perform?

Answer 1

I think MAC provides grant for re-transmission of same amount of data for which NACK is received. This can be same as pervious grant or it can be less or more grant. This could be decided based on channel condition. If channel condition is getting bad then MAC should provide more grant for same data but if channel condition is getting better then MAC can provide less grant for same data.