1. A wireless device comprising:one or more processors; and
memory storing instructions that, when executed by one or more processors, cause the wireless device to:
receive at least one message comprising configuration parameters of a plurality of cells, in a cross-carrier scheduling group, comprising a first cell and a second cell, wherein the second cell is identified by a cell identifier employing a first number of bits, and wherein the configuration parameters:
indicate that the second cell is a cross-carrier scheduling cell associated with the first cell; and
comprise the cell identifier and a first cell indicator field, wherein the first cell indicator field indicates the first cell and employs a second number of bits less than the first number of bits;
receive, via a control channel of the second cell, downlink control information (DCI) for a packet associated with the first cell and comprising the first cell indicator field; and
receive, based on the DCI and via radio resources of the first cell, the packet.