Ground-based technology In reference to the SJU Annual Work Programme 2016, this topics covers Section 3.5.3 (e) 2) topic d) and e).This project should examine what ground-based technologies are needed to support UTM, describe its technical architecture and indicate its performance requirements. It should address the use of communications, navigation and surveillance technologies, and how data supplied by these means should be used and by whom, including the need for traffic situation and other displays. The complications posed by the operation of drones beyond line of sight should be addressed.The specification of data links is not in the scope of this topic, and nor are issues related to the performance of networks needed to support them, or spectrum issues for any technologies considered in the concept for any purpose The operation of drones in VLL airspace introduces new challenges not encountered by manned aviation. Typically, outside the vicinity of airfields, there is limited infrastructure to support aerial operations, such as communication and surveillance. Furthermore, conventional navigation infrastructure may not be able to support the needs of VLL operations. It is necessary, therefore, to examine the concept of operations for VLL drone operations and to specify the ground-based technologies that are required to enable that concept. It is certain that the new concept of VLL operations by drones will need both new technologies and the re-use of existing technologies in order to function safely and efficiently. Correct specification of this technology will significantly facilitate the effective implementation of drone operations.