What is this hemispherical red dot under the hotel TV?

The hemispherical red dot under the hotel TV may be in the following two situations:

1. Smoke detector: Its function is to sense the smoke concentration in the air. When the concentration exceeds the set value, it will trigger a fire alarm. This kind of equipment is usually placed in hotels and other places to prevent fires.

2. Remote control receiver of digital set-top box: Digital set-top box is a device for receiving, decoding and displaying digital TV program information, and its remote control receiver can be hemispherical with red dots.

The specific judgment method can be judged according to the information such as the location and working environment of the equipment. If the equipment is under the TV and the working environment is relatively closed, it may be a smoke detector; If the equipment is under the TV and the working environment is relatively open, it may be the remote control receiver of the digital set-top box.