In the current development situation, the building intercom system still has problems. Because the traditional bus structure adopts the characteristics of analog transmission, there are many limitations in technology, mainly in:

1. Wiring structure problem, the bus type intercom system divides the signal transmission network into a total flat line (trunk bus), and a networked trunk line (branch bus). The equipment is formed from the management center, the area mouth machine, the ladder machine, and the indoor extension. Top-down hierarchical bus structure, from the main flat line to the network trunk line to the user's home line, all kinds of voice, video, control lines need to be laid separately dedicated cable, the type and quantity of wire is more, not only trouble during construction The cost of engineering wiring is also high.

2, busy problem: Because the networking uses the bus structure, there is only one public channel, only one call is allowed at the same time. Although multiple management center machines are set in the community to accept calls, alarms, etc. of the user, but the line is blocked and cannot be played. Its due role.

3, networking problems: In recent years, with the emergence of some large-scale communities, the expansion and compatibility of building intercom systems have put forward higher requirements. Because the bus structure adopts the characteristics of analog transmission, it can not solve the problem of interfering with each other in the long-distance transmission of midrange, video and signals, and the problem of system busy. When the cell is large, there is difficulty in networking and the system runs after networking. Unstable or even some features are not possible.

4, anti-interference ability problem: the traditional bus structure uses analog transmission technology, the analog signal is easy to attenuate and distortion, when the long-distance transmission needs to add video amplifier, not only the network cost increases, the anti-interference ability of the whole system is also poor, often there is no Signals or images and sounds are not disturbed.

5, system stability problems: Most products are limited to calls, unlocking and other functions, equipment usage is low, although some intercom products integrate anti-theft alarm and other three-table copy, information release and other functions, but due to the existence of system structure The problem of reuse, once the system's power supply or transmission network has problems, other systems (such as alarm systems) will also face embarrassment, the security stability of the entire system is greatly reduced.

6. System compatibility problems: Due to the lack of industry standards, the standards of wiring and product interfaces of various manufacturers are not uniform, and products cannot be interconnected, resulting in difficulty in integration of building intercom systems. Intercom systems are difficult to interconnect with other systems and cannot share communities. The integrated wiring, not only the large amount of engineering installation, can not achieve socialization and industrialization in terms of product, construction and after-sales service, which is not conducive to the industrialization development of the entire building intercom industry.

The traditional bus structure intercom system determines the inherent defects of its products due to the technical characteristics of its analog transmission. These shortcomings not only seriously affect the stability and reliability of the whole system, but also hinder the entire video intercom industry. Further development.