“…On the other hand, the smart city concept may encounter some obstacles about the security and privacy issues, which drives much research to work on like, recognizing people' faces [10,11] to access restricted areas [8][9][10], improving traffic flows by partly autonomous drones and vehicles [12] [13], traffic management and smart tracking, assistance systems [14,15], predictive maintenance [16,17], and last but not least, smart waste management [18].…”