This paper discusses the challenges of large scale integration within the context of the massive collaborative mobile & wireless systems beyond 3G research project Daidalos. It first examines the relationship of the Daidalos architecture. It then identifies an integration model that was used for the project, with an overview of the testing processes, tools, and methodologies employed. Next, discusses the Daidalos demonstration scenario, and shows how it was used in the integration execution validation and verification activity of the project. The article closes with a discussion of the research necessary to develop these capabilities further.