General approach for interoperation across Trust Networks is described in [LibertyInterFed], which focuses on the token passing flows in inter-federation situation. In addition to token passing, interoperability at data level is needed, i.e. the ontologies in use in the different Trust Networks either need to be the same or they need to be mapped. In particular, authorization critical data needs to be mapped.
Next version of this deliverable (D2.1 M30) will provide specifics of interoparation, based on TAS3 research and implementation experience.