sentences:  However, due to the node D backoff time period the probability to capture the medium during this small time interval is not high.To increase the per-node fairness, MACAW introduces a new control message called "Request for Request to Send" (RRTS).Now, when node C, which cannot reply earlier due to ongoing transmission between node A and node B, sends an RRTS message to node D during next contention period, the recipient of the RRTS (node D) immediately responds with an RTS and the normal message exchange is commenced.