A factory is implementing a device movement tracking system to monitor the movement and location history of devices used by employees.

Employees are responsible for manipulating various devices in the area. The manipulation detail can be stored in the operation table. The factory has deployed gateways to collect geographic data of operation movement information sent by the device in real time. $($Assume the movement of the employee and the devices are recorded together$)$

Hint:

Each gateway detection range may cover more than one area.

Each area may have many movement details.

Employees may operate more than one device, and gateways detect the movement data generated during operations. $($read the given details carefully on how the movement details are stored$)$