U-space is an enabling framework including a set of new services along with specific procedures designed to support safe, efficient and secure access to airspace for large numbers of drones. U-space is therefore not to be considered as a defined volume of airspace, which is segregated and designated for the sole use of drones. U-space services will rely on a high level of digitalisation and automation of functions, whether on board the drone or an element of the ground-based environment. As such the implementation of new services is associated to airborne capabilities and adequate/qualified ground infrastructure. Complementary infrastructure may be required if the existing ATM infrastructure does not meet necessary requirements. U-space framework includes a safe, secure, clear and effective interface to manned aviation, ATM/ANS service providers and authorities. U-space is capable of ensuring the smooth operation of drones in all operating environments, and in all types of airspace. U-space operations will also enable national military airspace defence systems to react to any drone-related situations deemed critical to national security. U-space is developed and deployed in a more agile way using shorter lifecycles in which technologies are deployed as they get mature. This is materialised through 4 phases (U1, U2, U3, U4) which serve as a basis for the gradual deployment of services.