Smart Cities innovation ecosystems are based on an infrastructure forinnovation. This infrastructure is built upon what within FIREBALL we are calling "common assets": resources of various types that can be selected, combined,shared and used by those who want to engage in living labs innovation projects.In this report, common assets types such as technical infrastructures, userdriven open innovation methods and tools, test bed facilities and usercommunities are identified and characterized based on a number of cases. Thecharacterization results into an overview and analysis how configurations of suchcommon assets can be tailored to the needs and requirements of Smart Cities.The work reported in this deliverable forms the basis for describing mechanismsfor access and governance of the common assets (D1.3). Also it is of relevanceto, and has been developed in close coordination with, the Landscape andRoadmap as developed in D2.1, which contains a number of "Smart City" casestudies where common assets are being studied as well.The work presented in this deliverable has been subject of several FIREBALLworkshops where the concept of common assets has been discussed andelaborated: * Future Interne Assembly (FIA) conference, Ghent, December 2010, workshopon "Smart Cities and Future Internet Experimentation". Workshop jointlyorganized with FIRESTATION. * Future Internet Assembly (FIA) conference, Budapest, May 2011, workshopon "Smart Cities and FIRE: Experimentation and Living Labs for the FutureInternet". Workshop jpointly organized with FIRESTATION. * ICE 2011 conference, June 2011, Aachen: workshop "Common Assets forSmart Cities Living Labs Innovation: IT Infrastructures, methods and usercommunities".The work has been subject of elaborate discussions with FIA members and alsohas resulted in a joint proposal for a Support Action in FP7-ICT (currently underevaluation).