An Access Network (AN) can send an acknowledge message (ACK) to an Access Terminal (AT) to indicate that the AN has successfully decoded the data received in the first set of slots of the first data packet. The AN can send a negative acknowledge message (NAK) to the AT to indicate that the AN has not...http://www.google.de/patents/US7564818?utm_source=gb-gplus-sharePatent US7564818 - Reverse link automatic repeat request
