Patent attributes
A wireless device receives at least one radio resource control (RRC) message comprising configuration parameters of a plurality of cells. The plurality of cells are grouped into a plurality of timing advance groups (TAGs). The TAGs include a primary TAG comprising a primary cell, and a secondary TAG (sTAG). The sTAG comprises a secondary cell configured with scheduling request (SR) resources. The wireless device receives a media access control (MAC) activation command indicating activation of the secondary cell. The wireless device determines that the secondary cell has an invalid SR resource when in a subframe: an SR process is pending, the SR resources are configured, and a time alignment timer of the sTAG is not running. The wireless device transmits a preamble via the primary cell in response to the determining that the secondary cell has the invalid SR resource.
