Patent ID: 8537739

Claim:
A method comprising: a) receiving, by a wireless device in a plurality of wireless devices, at least one control message from a base station, said at least one control message: i) causing in said wireless device: (1) configuration of a plurality of cells comprising a primary cell and a plurality of secondary cells; and (2) 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: (a) 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; and (b) a secondary cell group comprising a second subset of said plurality of secondary cells, said second subset comprising a reference secondary cell, uplink transmissions in said secondary cell group employing a second synchronization signal on said reference secondary cell as a secondary timing reference; and ii) comprising a plurality of common parameters having the same value for wireless devices in said plurality of wireless devices, said plurality of common parameters comprising the following parameters for each of at least one first secondary cell in said plurality of secondary cells: (1) a plurality of random access resource parameters; and (2) a plurality of power control parameters for random access preamble transmission; and b) receiving, by said wireless device, a control command to from said base station, said control command being: i) configurable to cause transmission of a first random access preamble on a secondary cell in said secondary cell group, said secondary cell being one of said at least one first secondary cell; and ii) unconfigurable to cause transmission of a second random access preamble on any secondary cell in said primary cell group; and wherein one or more second secondary cells in said primary cell group are not configured with usable random access resources for said wireless device.