ED-339 covers solely the indirect exchange approach to sharing NID data among USSPs and the provision of that data to other Authorised Users. It specifies the interfaces (information data model, messages structure and communication protocols) to be used in such an approach.
The initial motivation for this document is to provide a framework for indirect exchanges in compliance with the European U-space regulation. It is intended to support this paradigm wherever Network Identification (NID) information may need to be shared, including outside U-space airspace or in jurisdictions beyond Europe.