Investigation on Mobility Management for Carrier Aggregation in LTE-Advanced

In Long-Term Evolution-Advanced (LTE-A), which is currently in the process of standardization in the 3rd generation partnership project (3GPP), carrier aggregation (CA) was introduced as a main feature for bandwidth extension while maintaining backward compatibility with LTE Release 8 (Rel. 8). In the CA mode of operation, since two or more component carriers (CCs), each of which is compatible with LTE Rel. 8, are aggregated, mobility management for CCs such as inter/intra-frequency handover, CC addition, and CC removal is needed to provide sufficient coverage and better overall signal quality. Therefore, the signaling overhead for Radio Resource Control (RRC) reconfiguration for the mobility management of CCs in LTE-A is expected to be larger than that in LTE Rel. 8. In addition, CA allows aggregation of cells with different types of coverage, and therefore, the signaling overhead might be dependent on the coverage of each CC assumed in a CA deployment scenario. This paper presents evaluation results on the CC control overhead with several CC management policies in some CA deployment scenarios, and shows that the increase in the control overhead is not significant even in a CA deployment scenario with overlaid picocells.