A wireless device receives an RRC message comprising configuration parameters of radio resources of a control channel. The radio resources comprise multiple sets of resource blocks in a subset of subframes. The RRC message indicates the subset of subframes and a first starting symbol of both the control channel and a data channel in the subset of subframes. The configuration parameters comprise an array of parameters. Each element in the array comprises frequency resource parameters for a set of resource blocks. The multiple sets of resource blocks comprise non-overlapping sets of resource blocks in the subset of subframes.