A method, implemented by a wireless transmit/receive unit, WTRU, of monitoring a radio link, the method comprising: operating with a set of downlink, DL, component carriers including: a plurality of component carriers including a primary component carrier, PCC, paired with a first uplink carrier and including a physical downlink control channel, PDCCH, monitored by the WTRU, and at least one secondary component carrier, wherein one of the at least one secondary component carrier is paired with a second uplink carrier and includes a PDCCH monitored by the WTRU; counting out-of-synch indications for the PCC by monitoring out-of-synch indications of the PCC and counting out-of-synch indications for the one of the at least one secondary component carrier by monitoring out-of-synch indications of the one of the at least one secondary component carrier; and on a condition that a radio link failure of the one of the at least one secondary component carrier is detected: sending a notification of the radio link failure to an evolved Node B, eNB, associated with the first uplink carrier, and suspending uplink transmissions on the second uplink carrier paired with the one of the at least one secondary component carrier, and suspending the one of the at least one secondary component carrier, wherein the radio link failure of the one of the at least one secondary component carrier is detected based on: a recovery timer in the WTRU starting based on a detected number of out-of-synch indications of the one of the at least one secondary component carrier being counted, and the recovery timer expiring before a predefined number of in-synch indications for the one of the at least one secondary component carrier is counted. operating with a set of downlink, DL, component carriers including: a plurality of component carriers including a primary component carrier, PCC, paired with a first uplink carrier and including a physical downlink control channel, PDCCH, monitored by the WTRU, and at least one secondary component carrier, wherein one of the at least one secondary component carrier is paired with a second uplink carrier and includes a PDCCH monitored by the WTRU; a plurality of component carriers including a primary component carrier, PCC, paired with a first uplink carrier and including a physical downlink control channel, PDCCH, monitored by the WTRU, and at least one secondary component carrier, wherein one of the at least one secondary component carrier is paired with a second uplink carrier and includes a PDCCH monitored by the WTRU; counting out-of-synch indications for the PCC by monitoring out-of-synch indications of the PCC and counting out-of-synch indications for the one of the at least one secondary component carrier by monitoring out-of-synch indications of the one of the at least one secondary component carrier; and on a condition that a radio link failure of the one of the at least one secondary component carrier is detected: sending a notification of the radio link failure to an evolved Node B, eNB, associated with the first uplink carrier, and suspending uplink transmissions on the second uplink carrier paired with the one of the at least one secondary component carrier, and suspending the one of the at least one secondary component carrier, sending a notification of the radio link failure to an evolved Node B, eNB, associated with the first uplink carrier, and suspending uplink transmissions on the second uplink carrier paired with the one of the at least one secondary component carrier, and suspending the one of the at least one secondary component carrier, wherein the radio link failure of the one of the at least one secondary component carrier is detected based on: a recovery timer in the WTRU starting based on a detected number of out-of-synch indications of the one of the at least one secondary component carrier being counted, and the recovery timer expiring before a predefined number of in-synch indications for the one of the at least one secondary component carrier is counted. a recovery timer in the WTRU starting based on a detected number of out-of-synch indications of the one of the at least one secondary component carrier being counted, and the recovery timer expiring before a predefined number of in-synch indications for the one of the at least one secondary component carrier is counted.