There are two types of carrier aggregation: continuous and non-continuous.
so
In continuous
called
aggregation, contiguous component carriers within the same operating frequency band are aggregated intra-band contiguous. -
| J frequency
For non-contiguous allocation it could either be intra-band, (i.e. the component carriers belong to the same o band, but are separated by a frequency gap) or it could be inter- perating
belong to different operating frequency bands