Carrier Aggregation (CA) aggregates multiple component carriers to maximize bandwidth for delivering the peak data rate of 1 GBPS. CA provides backward compatibility with previous releases and enables utilization of spectrum from different parts of the frequency space. This white paper provides exhaustive insights into Carrier Aggregation as a technology and discusses the various types of carrier aggregation and the concept of Cross-Carrier Scheduling. It also talks about the impact of CA on design and implementation of User Equipment (UE) and how it has impacted the Resource Control (RRC), Media Access Control (MAC) and the physical layer protocols.