A wireless device receives a message assigning each second carrier to one of a first carrier group and second carrier group(s). The message comprises parameters for each second carrier. If the parameters comprise a carrier group index for a second carrier, the second carrier is assigned to one of the second carrier group(s) identified by the carrier group index. Otherwise, the second carrier is assigned to the first carrier group. The wireless device receives a time alignment command comprising the carrier group index and a time adjustment value.