Patent ID: 8553655

Claim:
A method comprising: a) receiving, by a wireless device, at least one control message from a base station, said at least one control message causing in said wireless device: i) configuration of a plurality of cells comprising a primary cell and a plurality of secondary cells; ii) configuration of a deactivation timer for a secondary cell in said plurality of secondary cells, said deactivation timer corresponding to a secondary cell restarting in response to a packet transmission on said secondary cell, said corresponding secondary cell deactivated in said wireless device in response to said deactivation timer expiring; and iii) assignment of each of said plurality of secondary cells to a cell group in a plurality of cell groups, said plurality of cell groups comprising: (1) a primary cell group comprising a first subset of said plurality of cells, said first subset comprising said primary cell, uplink transmissions by said wireless device in said primary cell group employing a first synchronization signal transmitted on said primary cell as a primary timing reference; and (2) a secondary cell group comprising a second subset of said plurality of secondary cells; b) receiving, by said wireless device, a control command configured to cause transmission of a random access preamble on random access resources of a reference secondary cell in said secondary cell group; and c) receiving, by said wireless device, a random access response on said primary cell in said primary cell group, said random access response comprising a timing advance command for said secondary cell group; d) transmitting first uplink signals in said secondary cell group, by said wireless device, employing a second synchronization signal on said reference secondary cell in said secondary cell group as a secondary timing reference, said reference secondary cell being an activated cell in said secondary cell group; e) selecting, autonomously by said wireless device, a new activated secondary cell in said secondary cell group as said secondary timing reference if all of the following conditions are satisfied: i) said reference secondary cell is deactivated or released in said wireless device; and ii) at least one secondary cell in said secondary cell group is active in said wireless device; and f) transmitting second uplink signals in said secondary cell group, by said wireless device, employing a third synchronization signal on said new activated secondary cell as said secondary timing reference.