MRT indicator light / light devices

When we take the MRT, there are usually some difficulties for us to find an uncrowded carriage. Our concept is to use the thermal-sensed device in the carriage, and connected to the indicator light system by 3G transmission, the light would starts to show when the MRT is about to come, then to change the amount while passengers entering or leaving the car. Therefore, they would know which carriage has much less people.