Design And Implementation Of Networking Intercom System

With the development of the economy and the improvement of people's living standards, people's quality of life put a higher demand, which is reflected in many ways. In this paper, the author proposed solutions of LAN-based building digital video intercom system, aiming at solving some existing problems in traditional building intercom system and helping improve the user experience.The system uses Samsung Exynos4412 as the core chip. The Exynos4412 is a 32-bit RISC quad-core chip of high performance, its high-speed computing capabilities ensures the extensions of the latter software functions. Exynos4412 has 1080 @ 30 fps HD hardware codec capabilities, which is the premise of high-quality audio and video calls, the system uses the network transmission audio and video d ata, effectively avoiding problems, such as poor stability, anti-interference ability, limited transmission distance and other defects, which exist in traditional analog systems. LAN-based design can provide a good compatibility when integrating with intelligent community system in the future.For the complex wiring in traditional building intercom systems, the paper put forward applying POE power supply technology, which is widely used in video monitoring system, to the building intercom system, using the network cable for the power supply of indoor and outdoor terminal eliminate the power line wiring and reduce the wiring difficulty, to a certain extent.The system uses liblinphone, a open source VOIP library, in the software development of video call. liblinphone has easy-to-use software interface, greatly reduces the difficulty of software development and accelerates project development progress. The echo cancellation algorithm of Linphone is also of great significance in building visual intercom, eliminating separate research on Algorithm of echo cancellation.The system introduces wireless networking to deal with digital upgrade for older properties and some inconvenient wiring situation. When using battery power, the indoor terminal could be placed throughout the room, rather than fixed near the door the same as a traditional intercom system. USB interface wireless network card using in the system make it possible to cut hardware conveniently under different networking circumstances.