Hybrid Automatic Repeat Request (HARQ) operation in an asymmetric multicarrier communication network environment is performed, in one embodiment, by receiving resource allocation information from a base station, transmitting the HARQ packet to the base station in a transmit time interval (TTI) corresponding a first or second partition of an uplink allocation interval on a second carrier, and receiving HARQ feedback information corresponding to a previous HARQ packet transmission. A TTI in a subsequent uplink allocation interval is determined based on the partition of the uplink allocation interval in which the HARQ packet is transmitted if the HARQ feedback information indicates negative acknowledgement. The HARQ packet is transmitted to the base station in the determined transmit time interval of the subsequent uplink allocation interval on the second carrier.