I. INTRODUCTION  
II. SOCIAL DISTANCING: A FUNDAMENTAL BACKGROUND  
A. Social Distancing  
B. Positioning Technologies  
IV. OTHER EMERGING TECHNOLOGIES FOR SOCIAL DISTANCING  
A. Computer Vision  
B. Ultrasound  
C. Inertial Sensors  
D. Visible Light  
E. Thermal  
F. Artificial Intelligence  
V. OPEN ISSUES AND FUTURE RESEARCH DIRECTIONS  
A. Security and Privacy-Preserving in Social Distancing  
B. Real-time Scheduling and Optimization  
C. Incentive Mechanism to Encourage Social Distancing  
D. Pandemic Mode for Social Distancing Implementation  
VI. CONCLUSION