U-space Proposals must include research activities leading to further development of the U-space concept. The following non-exhaustive research areas of interest have been identified by the SJU:Application area 1: use of U-space services by general aviationThe objective is to research if U-space services that are being developed for drones may also be useful for manned aviation, including general aviation. This could include access to local weather information, dynamic obstacle data bases, information on planned or active drone activity, geo-fenced volumes or additional services provided to the drone community via a ground-based data communications network.Application area 2: Common altitude referenceUAS must be able to keep clear of each other, and of manned aircraft using the same airspace. To ensure vertical separation from these aircraft, it is essential that they use the same altitude reference. They must also be able to keep clear of objects on the ground - buildings, cranes, trees, etc. - and of course people and property in general. Their pilots (or their on-board flight controllers) need, therefore, to be able to understand their height above the ground in an unambiguous way, to be able to relate this to databases of objects and terrain, and to the declared altitude of other aircraft.EUROCONTROL and EASA have published a discussion paper and describes potential solutions, while identifying areas for additional research. Work under this topic should examine the EUROCONTROL/EASA discussion paper and augment its analysis in the light of additional investigation. It should also present final conclusions that propose a justified and tested solution to the common altitude reference issue.Application area 3: Urban airspace rulesThe largest concentration of drones is expected over large populated areas. This has led to the proposal that airspace above urban areas (e.g. up to 1000 ft. above) be declared drone-only airspace, where rules of the air do not apply (because there are no manned flights). Manned flights would still be possible (e.g. security forces, emergency services), but they would need special authorization, and proposals should be described about how this could safely be done without adversely affecting priority manned aviation. There are important challenges associated to this concept, both from the operational point of view and from the societal point of view (noise impact, acceptable accident rate). Research should also cover urban-specific issues such as, inter alia, C2 performance in a heavily built-up area, GNSS performance and the potential impact of micro-climates. Finally, models for the design and management of drone trajectories – fixed or otherwise – should be proposed and analysed to support potentially large numbers of simultaneous drone operations. Bids should review the existing literature and describe how their proposed work would address the existing challenges.Application area 4: flight-planning and demand and capacity balancing for dronesAs demand for drones over populated areas explodes, there will be a need for limiting the density of flights. Research should explore the initial U-space DCB concept, which may require drones to flight-plan and get approval before departure.Application area 5: U-space separation management serviceWith increasing numbers of drones in flight, there may be a need to ensure that they remain separated from each other and from manned aviation. Note that this is distinct from the requirement to avoid collisions; this topic considers a formal process whereby drones are separated from other drones and manned aviation according to agreed concepts and minima, equating to the ICAO second layer of conflict management for manned aviation: separation provision. This research topic should consider under what circumstances separation provision will be necessary, and how it could be implemented. There is a need to establish who will be the separator (the drone itself or the U-space service), what the separation minima will be, and what the separation management processes will be. There is also a need to define when separation will be procedural (e.g. two drones on different routes can be deemed separated without needing to check their positions in real time), and when tactical separation will be applied (in which case the surveillance tracks must be separated beyond defined separation minima). For tactical separation, it is necessary to establish who will take the role of the separator (the U-space service or the drone), and what are the performance requirements needed by communications, navigation and surveillance systems to support the provision of tactical separation. For procedural separation, navigation performance requirements will need to be developed. The research should also consider how such separation services should behave when airspace is shared with manned aviation, with and without ATC. Finally, it should consider how separation services relate to complementary collision-avoidance technologies and procedures.Application area 6: Drone traffic management for airportsIt is expected that large airports will operate fleets of drones in support of airport operations, e.g. for runway and lighting inspection. Research will develop an airport drone management concept that ensures that airport drones can perform their function without posing a risk to operations at the airport.The research should assess the feasibility and potential benefits of large airports operating fleets of drones in support of airport operations (e.g. for transporting spare parts or high value cargo, for runway and lighting inspection, etc.)In particular, the research must develop of how airport service drones could be managed, de-conflicted, in order to smoothly move around their allocated areas in a safe and efficient manner.Please note that the development of geofencing aspects are out of the scope of this research topic (they are already covered by GEOSAFE l). However, proposals in this area may develop geofencing requirements specific for airport service drones if they deem them necessary.The U-space research areas described above do not constitute a prescriptive list; proposals addressing research outside of the research areas on the list are welcome, provided adequate justification and background are provided in the bid.Projects working in this area must be willing to share information with one another and reserve effort for coordination with other projects in this area and with SJU activities that bring together all U-space research efforts (e.g. U-space demonstrations). It is expected that the introduction of new delivery technologies such as drones, and mobility as a service will alter mobility which will result in large improvements in the quality of urban living. These unmanned aerial systems (UAS) require new kind of services. U-space services provide services to UAS flying without services from ATM, but may take place in airspace shared with manned aviation, some of which may be receiving ATC services. This exploratory research challenge refers to the development of new U-space services (especially in the more advanced U3 and U4 service levels), as well as to the linked regulatory challenges. Advanced U-space services will enable the safe and efficient operations of large numbers of drones without adversely affecting manned aviation.