A Global System for Mobile Communications (GSM) network supports multi-carrier operation on the downlink and/or uplink for a mobile station. The mobile station receives an assignment of multiple carriers for a first link in the GSM network, receives an assignment of at least one carrier for a second link in the GSM network, and exchanges data with the GSM network via the multiple carriers for the first link and the at least one carrier for the second link. The first link may be the downlink and the second link may be the uplink, or vice versa. The mobile station may receive data on multiple carriers at the same time for multi-carrier operation on the downlink. The mobile station may transmit data on multiple carriers at the same time for multi-carrier operation on the uplink.