I. Introduction
Over the past decade, developments in the aviation industries have led to a growing number of aerial platforms and traffic across the globe. This increase has been augmented by the recent advances in the field of unmanned aircraft systems (UAS) and GNSS (Global Navigation Satellite Systems) positioning that has led to the phenomenal growth in the number of UAS platforms. A growing number of application areas such as infrastructure inspection, precision agriculture, search and rescue and cargo delivery have attracted many new and legacy operators of these areas to utilize UAS. On the other hand, Artificial Intelligence (AI) and autonomous mobility are expected to impact the modes of transportation across all the domains of ground, air and sea surface and sub-sea. Autonomous on-demand mobility is considered to form the new paradigm in urban mobility. To accommodate for the increasing traffic, especially at the lower altitude in urban areas, robust traffic planning and management is required. The requirement for the safe integration of the UAS into the air space has become ever more pronounced and critical in the recent years and one that presents a major technological and regulatory challenge for the eco-system as a whole. Regulators and aerospace organizations around the world are working diligently for the solutions to ensure safe integration of UAS into national airspace. In the US, NASA introduced the UAS Traffic Management (UTM) concept in July 2015 [1] at its Ames Research Centre. Several topics such as safety and security and strategies for low-altitude traffic management were discussed and have been part of the UTM development. The project considers air traffic management system and de-confliction requirements for small UAS under 400 ft in beyond visual line of sight operations. In 2018, FAA announced that the UTM concept and technology will be transferred to industry for further developments and implementations.