Buy the wireless intercom system should be the different residential structure, area distribution and functional requirements to select, some suitable for non closed management of residential, can realize call, intercom and unlocking function, and has the function of luminous indication; and is suitable for low layer to high residential structure; closed management areas it can be used with safety alarm function of the indoor machine, the user can according to their need to install Menci, infrared probe, smoke alarm, gas leakage alarm device. As facultative Gu different user needs and economic conditions, the visual system of color and monochrome machine extension compatibility, users can use color machine, also can use black and white machine, can also choose not to take the visible function intercommunication indoor machine; for the convenience of engineering wiring, according to different area distribution, large system bus can adopt star type wiring and circular wiring. In order to solve the system of signal attenuation, in the same cable video duplex transmission dual amplification using intelligent signal booster.