# The Development of an Advanced Air Mobility Flight Testing and Simulation Infrastructure
## 2 Key Concepts and System Requirements  
With the AAM concept, current air transportation will evolve by extending its operations through various use cases such as air cargo/meal deliveries, air taxis and shuttles, and surveillance flights at VLL. AMU-LED is one of the VLD projects for implementing and testing the AAM concept. AMU-LED's purpose is to validate the defined ConOps, which includes new approaches for realizing the AAM concept. Different from the other projects, AMU-LED specifically proposes a new airspace structure where some types of vehicles and their flight levels are differentiated, proposes relevant possible U-space services, and outlines a system-wide contingency management concept. In this section, some of the key concepts that are defined under the AMU-LED ConOps are covered [45]. Figure 1 depicts the operational architecture that is adopted in the AMU-LED project. All the roles and responsibilities of each and every stakeholder and their interconnections are provided under that notional architecture for both centralized and decentralized approaches. According to it, traditional aviation consists of current air transportation system and its users. All the connection supposed to be through a common information service (CIS) provider (except in case of an emergency--there can be a direct connection between the air navigation service provider (ANSP) and operators), which mainly acts as a database and ensures data flow, especially for operational data. The considered data are provided to both the traditional aviation market and the open service market, which accommodates multiple USSPs. USSPs are responsible for providing various services, such as strategic conflict resolution, risk analysis assistance, conformance monitoring, contingency management, and registration assistance, to create a safe and efficient traffic environment. These services are provided to innovative air mobility users consisting of SPV and HPV flights. All AAM-related activities are supported and enhanced with supplementary data service providers (SDSPs) where the information related to weather, communication coverage, electromagnetic interference, and so forth are provided. An infrastructure block refers to the  
vertiports where the origin and destination points are represented. The information flow regarding vertiport availability or adverse conditions around a vertiport is ensured through a CIS provider for centralized architecture and USSPs for decentralized architecture. Finally, national authorities are responsible for registration, legal actions, and the reporting of any important case that directly provides input to CIS. Categorization for vehicles is given as standard performing vehicles (SPVs), which refers to small UASs and high performing vehicles (HPVs) and includes air taxis and big cargo vehicles. This approach is valuable since it also refers to problems regarding operational activities of vehicles with different sizes. For instance, separation complexity between SPVs and HPVVs has to be considered carefully since both have different dynamics, sizes, performances, and maneuver envelopes. This also applies to separation between HPVVs and conventional manned aviation. Operational layers corresponding to SPVs and HPVVs are defined as the standard performance layer (SPL) and the high performance layer (HPL), respectively [45; 46]. The illustration of that layered airspace structure is as given in Figure 2.  
The layered airspace concept at VLL requires redesigning the existing U-space services or defining new services. Considered services have a wide range and are related to registration, identification and tracking, geoawareness and geofence provision, operational plan optimization, risk analysis assistance, flight authorization, conformance monitoring, strategic and tactical conflict resolution, contingency and emergency management, environment information, digital logbooks, and procedural and collaborative air traffic control (ATC) interfaces [47].