Asymmetric digital subscriber lines were widely used for broadband connections in ordinary households.
ADSL is the common abbreviation, often used in everyday contexts, while 非対称デジタル加入者線 is the full formal term.
Compound of 非対称 (asymmetric), デジタル (digital), 加入者 (subscriber), and 線 (line), calqued from English 'asymmetric digital subscriber line'.