A wireless doorbell (wireless door phone or wireless doorbell) is also called a wireless remote doorbell or a remote doorbell. Common wireless doorbells have a wireless doorbell that does not use a battery, a normal wireless doorbell, and a visible wireless doorbell. The wireless doorbell is a type of doorbell developed using civilian wireless technology like Zigbee, WIFI, Bluetooth. The general wireless doorbell has an effective transmission distance of about 40 meters. The video or voice signal is wirelessly transmitted using 2.4G frequency, and the transmission distance can reach 400 meters in an unobstructed environment. The wireless doorbell does not require wiring, and the installation is simple and flexible, but the transmission distance is greatly affected by the transmission distance and the on-site environment. The wired doorbell is just the opposite. A normal wireless doorbell requires a battery and needs to be replaced in time. The wireless doorbell without a battery relies on the button to power the technology to get rid of the battery limit. The wireless doorbell is divided into the content of the transmission, and can be divided into a wireless non-visual doorbell and a wireless video doorbell. Wireless non-visual doorbells only transmit voice signals. When the visitor rings the doorbell, the owner can only hear the sound and does not see the image of the visitor. The wireless video doorbell can both make voice calls and see the visitors' images. The wireless doorbell is divided into active wireless doorbell and passive wireless doorbell from the power supply of the transmitter. The passive wireless doorbell means that the transmitter is driven by the energy of the doorbell to be converted into electric energy (no battery is required). Active wireless doorbells rely on internal battery power.