Learn in the textbookAdvancement of Mobile Communications and Device Technology
DefinitionCarrier aggregation (キャリアアグリゲーション) combines radio waves from several frequency bands (周波数帯) and uses them together, making wireless communication faster and more stable.
ExplanationIt is also abbreviated CA. Each added band widens the usable bandwidth, so more data can flow. When the signal in one band is weak, another band can make up for it.
AnalogyPicture traffic that used a single one-lane road now flowing along neighboring parallel roads at the same time.
Memory hookHere "carrier" means not a phone company but the radio wave that carries data (a carrier wave), and "aggregation" means gathering together.