thout spatial multiplexing and up to two transport blocks, in the case of spatial multiplexing, and one independent HARQ entity per scheduled component carrier. Each transport block is mapped to a single component carrier. A UE may be scheduled over multiple component carriers simultaneously, but only one random access procedure can be performed at any time. In multi-carrier operation, the same DRX operation inherited from Rel-9 is applied to all configured component carriers (i.e., identical active time for PDCCH monitoring). The RLC and PDCP protocols of 3GPP LTE Rel-8 are also relevant to carrier aggregation. In 3GPP LTE, a cell is identified by the E-UTRAN Cell Global Identifier, which corresponds to the transmission of system information on one component carrier. The 3GPP Rel-8 relevant system information is broadcast on backward-compatible component carriers. Each component carrier provides system information which is specific to that carrier. In multi-carrier mode, the UE only has one RRC connection with the network. A single cell also known as the special cell provides the security context, i.e., E-UTRAN Cell Global Identifier (ECGI), Physical Cell Identifier (PCI), Absolute Radio-Frequency Channel Number (ARFCN), and Non-Access Stratum (NAS) mobility information such as tracking area identity. There is only one such cell per UE in the RRC_Connected mode. After RRC connection is established, the reconfiguration, addition, and removal of component carriers can be performed using RRCConnectionReconfiguration including mobilityControlInfo (i.e., intra-cell handover) or RRCCon- nectionReconfiguration without mobilityControlInfo for addition of component carriers, and for the removal of component carriers with the exception of the component carrier corresponding to the special cell. In intra-LTE handover scenario, the RRCConnectionReconfiguration with mobilityControlInfo or the handover command can remove, reconfigure, or add component carriers for usage in the target cell. When adding a new component carrier,