Door entry systems are essential for managing visitor access within apartment blocks. These systems enable residents to receive visitors, deliveries, and tradespeople. With the emergence of video intercom, residents can now verify who is at the door before buzzing them in. Using apartment audio or video phone/tablet and mobile phone, residents can converse with visitors from anywhere. 

The primary door camera can keep a visitor's video record in accordance with data policy. Meanwhile, individual apartment indoor stations can privately record specific conversations according to each resident's preference. Trades buttons, which historically allow unrestricted access at certain times, can be replaced by keycodes for regular visitors, such as postmen, for example. 

Instead of communal door keys, access control methods (such as ID cards, fobs, keycodes, facial images, and QR codes) can be built into the door entry system. This eliminates the difficulty of controlling the whereabouts and proliferation of keys and saves the expense and inconvenience of periodically changing the locks. This can also be extended to other communal areas, such as bin stores. 

Older door entry systems can be cost-effectively upgraded using the original wiring or a combination of existing and new wiring when systems are extended. The mobile phone GSM network can provide door entry via mobile phone without any wiring required. In the future, door entry systems will offer more outstanding capabilities and business value to meet the demand for intelligent living environments and communities.