Ambient Assisted Living (AAL) is currently being studied by research institutions and industry, and it is expected to become a reality in the near future. One of the main issues in AAL is the heterogeneity of technology, which demands a major effort to allow interoperability of elements operating in a smart environment. Service-oriented frameworks such as OSGi provide beside other interesting facilities an adequate way to handle this heterogeneity and are often used as framework platforms which support smart home environment systems. However, there is also heterogeneity among different AAL projects, as every research team develops its own smart environment. Thus, devices and services definitions usually differ from one project to another. In the following a proposal for a Common OSGi Interface is introduced, which publishes both interfaces for devices and services of AAL related scenarios. By using these interfaces, an AAL application designer will be able to take advantage of existing device and service developments and ensure interoperability with other systems.