This disclosure relates to techniques for supporting asymmetric uplink and downlink bandwidth allocations for a wireless device, and for dynamically modifying the bandwidth allocations for a wireless device, in a wireless communication system. A cellular communication link may be established between a base station and a wireless device. The base station may determine an uplink bandwidth allocation and a downlink bandwidth allocation for the wireless device. The uplink bandwidth allocation and the downlink bandwidth allocation may be selected based on different criteria and may include different amounts of bandwidth. Indications of the uplink bandwidth allocation and the downlink bandwidth allocation may be provided to the wireless device. The base station and wireless device may communicate according to the uplink bandwidth allocation and the downlink bandwidth allocation.