What is Carrier Aggregation?

Carrier Aggregation (CA) is a feature of LTE-Advanced that allows mobile operators to combine two or more LTE carriers into single data channel to increase the capacity of the network and the data rates by exploiting fragmented spectrum allocations.

This technology can be applied to either the FDD or TDD variants of LTE with a maximum of five component carriers, each with a bandwidth of up to 20 MHz, resulting in a total transmission bandwidth of up to 100 MHz.

Types of Carrier Aggregation (CA)

Intra-band Carrier Aggregation: This form of carrier aggregation uses a single band. It is further divided in to two parts:

• Contiguous: This is the easiest form of LTE carrier aggregation to implement. In this, the carriers are adjacent to each other. In this case, you only need a single transceiver as the signal is considered to be a single enlarged signal.

• Non-contiguous: This one is slightly complicated as the carriers use the same operating band but are not adjacent to each other. So you need two transceivers because the signal can’t be treated as a single signal, adding to complexity and cost.

Inter-band non-contiguous: This form of carrier aggregation uses different bands. This is more challenging as the carriers are from different operating bands. So you need multiple transceivers to transmit/receive signals using this type of CA, adding to cost, complexity and creating space constraints.