Methods described herein are for wireless communication systems. One aspect of the invention is directed to a method for a HARQ process, in which the HARQ process includes a first transmission of an encoder packet and at least one retransmission. The method involves allocating a transmission resource for each respective transmission. The method involves transmitting control information from a base station to a mobile station for each respective transmission. The control information includes information to uniquely identify the HARQ process and an identification of one of a time resource, a frequency resource and a time and frequency resource that is allocated for the transmission. In some embodiments of the invention, specific control information is signalled from a base station to a mobile station to enable RAS-HARQ operation. In some embodiments of the invention, retransmission signaling in included as part of regular unicast signaling used for both first transmission and retransmissions. In some embodiments of the invention, a 3-state acknowledgement channel and associated error recovery operation enables the base station and mobile station to recover from control signaling error and reduce packet loss.