Carrier Aggregation (CA) is one of the key features of LTE-A [Download Speeds of at least 100 Mbps & Upwards] which allows telcos to combine multiple spectrums (carriers) within each band and across bands (such as 900MHz and 2100MHz) in a way that acts as a single contiguous spectrum band. This allows for higher capacity, bandwidth and speed. Basically for each connection, more spectrum is allocated with CA.
Most telcos operate on many different bands for 2G, 3G, 3.5G and 4G. A lot of these bands are operated independently and telcos rely on radio resource management to find the right balance for traffic load. But these generally have been inefficient ? data still continues to grow fast and also, and newer frequencies are being used for LTE.
CA provides the scope and flexibility to combine various bands ? basically allowing telcos to use all of their frequency allocations to provide 4G/LTE services. CA?s benefits include better speeds and higher capacity, better use of spectrum ? not many telcos even have 20MHz of contiguous spectrum and with CA implementation, there is scope to increase this to 100MHz virtually
