The Design And Development Of Video Intercom System Based On SIP Protocol

Video intercom system as an important part of preventive security technology systems, intelligent residential building the necessary infrastructure. Existing analog and digital video intercom system does not solve the manufacturers protocol compatibility issues, user equipment failure can not find alternative products, the customer can not use the video intercom system, residential property owners and visitors access inconvenience.For compatibility problem with existing video intercom system, the subject of international organizations proposed by IETF SIP standard communication protocol design video intercom system, so that the door can be compatible with other machines using SIP protocol video intercom system. Video intercom system, door and indoor units are used S5PV210 processor and Android operating system development, using G.729 audio codec format, using the H.264 standard video codec, audio and video using RTP network protocol for real-time transmission.Video intercom system in order to ensure the transmission of audio and video information fluency, in-depth study of the traditional TCP-Vegas algorithm and mainstream RED algorithm, an improved algorithm for congestion detection and control, implemented in RTP streaming media congestion control packet loss rate of less than 0.03, to ensure real-time transmission of complex networks, the video and audio information.Finally, the function indicators door and indoor units designed detailed test program, including audio and video transmission packet loss rate, command response time, system compatibility. With video phone, audio and video intercom mobile client test results show that the video image is clear and smooth, no Caton and mosaic, congestion detection algorithm and adaptive transmission control mechanism to reduce network bandwidth occupied by the door machine, to achieve lower packet loss rate. Door machine can respond within the time limits prescribed operation of the user, and can be on the market using standard SIP video phone were interconnection, its features and performance are expected to meet the system design requirements.