This document is the Operational Services and Environment Definition (OSED) for the Traffic Awareness and Collision Avoidance capability of a Remotely Piloted Aircraft System (RPAS) operating in Class A, B and C Airspace under Instrument Flight Rules and abnormal operation in the other airspace from D to G. It is intended to be used as a supporting document for implementation of ED78 process [Ref 1] in the definition of Safety and Performances Requirements (SPR) and Interoperability requirements (INTEROP). And has been developed in order to meet the specific requirements of the EUROCAE/ EUROCONTROL Scenario 1 (Enroute operation in class A B and C airspace defined in EUROCONTROL ‘Generic UAS ATM Safety Assessment Baseline Scenario 1 – Classes A, B or C En-Route Airspace’ (October 2008).