Patent ID: 8717866

Claim:
A wireless device comprising: a) one or more communication interfaces configured to communicate with a base station via at least one wireless link; b) one or more processors; and c) memory storing instructions that, when executed by said at least one or more processors, cause said wireless device to: i) receive at least one radio resource control message comprising a plurality of parameters of: (1) a first carrier and at least one second carrier; and (2) a first carrier group and at least one second carrier group, said first carrier group comprising a first subset of a plurality of carriers, said first subset comprising said first carrier, each of said at least one second carrier group comprising a second subset of said at least one second carrier; and causing assignment of each of said at least one second carrier to one of said first carrier group and said at least one second carrier group, wherein: (1) if said plurality of parameters comprise a carrier group index for a second carrier, said second carrier is assigned to one of said at least one second carrier group identified by said carrier group index; and (2) otherwise, said second carrier is assigned to said first carrier group; ii) receive a control command configured to cause transmission of a random access preamble on random access resources of a carrier in a second carrier group in said at least one second carrier group; and iii) receive a random access response on said first carrier, said random access response comprising a time alignment command for said second carrier group.