Sensor Networks Hierarchical Optimization Model for Security Monitoring in High-Speed Railway Transport Hub

Table 2

Hierarchical organization of sensor networks.

Sensor network	First hierarchy	Key area monitoring sensors	(i) Sensors in different key areas are independent and do not have any relevance; (ii) Sensors do not need adjustment after setting; (iii) Sensors have front-end event detecting software
	Second hierarchy	Passenger line monitoring sensors	(i) Sensors should be set following the passenger line; (ii) Sensors in same passenger line have association; (iii) Sensors do not need adjustment after setting; (iv) The data acquired by sensors should be continuously transferred to the control center to process
	Third hierarchy	Complete coverage monitoring sensors	(i) Sensors should cover all the function areas in HRTH; (ii) The monitoring areas of sensors should reduce overlaps as much as possible; (iii) Sensors can adjust monitoring areas after setting; (iv) The data acquired by sensors should be continuously transferred to the control center to be stored