A conceptual architecture for ambient assisted living is introduced as a contribution to the development of an ecosystem of products and services supporting active ageing. In order to facilitate understanding and better inter-relate concepts, a 3-layered model is adopted: Infrastructure layer, Care and assistance services layer, and AAL ecosystem layer. A holistic perspective of ambient assisted living, namely considering four important life settings is adopted: (i) Independent living; (ii) Health and care in life; (iii) Occupation in life; and (iv) Recreation in life.