Research in the field of Ambient Assisted Living (AAL) introduces assistive technologies in various contexts, e.g., medical applications for clinics, or activities in home environments. Assistive technologies have the potential to help prevent isolation and lack of social support arising from a growing number of older adults living in single person households in urban areas. In order to examine the role of such technologies and identify challenges and potentials of systems and services, we investigated existing literature of the past decade. Whereas many contributions support the individual user or social connection, only few integrate location-based information or urban structures. Future research is confronted with a multitude of challenges, e.g. considering network technologies, market uptake or adaptation, and potentials, e.g. the support or establishing of social neighborhood structures. This literature review contributes in achieving an overview of the state of the art and research areas that will draw an increasing focus according to demographic change.