US Patent 9319909 Devices for radio link monitoring

A user equipment (UE) configured for radio link monitoring is described. The UE includes a processor and instructions stored in memory that is in electronic communication with the processor. The UE monitors a radio link quality for a secondary cell (SCell). The UE also determines whether a physical layer problem is detected based on the radio link quality. If a physical layer problem is detected, the UE stops a time alignment timer (TAT) of the SCell or sets the time alignment timer (TAT) of the SCell as expired.