Analysis And Design Of The Remote Identification System Based On H.323 Protocol

H.323 protocol is the standard of multimedia communication for packet networks which is established by ITU-T. It can be used in many situations, such as video conference system, remote monitoring system, remote identification system and so on. The remote identification system is a novel application.The remote identification system discussed in this dissertation is mainly used in inspection and quarantine department, such as frontier inspection station and customs. When officials in these departments find some suspected species or species that is unknown before, they could contact the remote experts and diagnose these species timely and effectively using remote identification system. The study of the remote identification system will take a great convenience to prevent the alien invasive species and protect the new species, regardless of in scientific research or in application field.This dissertation analyzes the H.323 protocol family firstly, which include the structure of protocol stack, the composition of system based on H.323 protocol, the procedures in H.323 protocol and QoS.According to what have been talked above, this paper analyzes characteristics of the users and puts forward the composite structure of remote identification system. This dissertation also gives out a control mode of remote identification system compared with video conferencing system.The dissertation researches the composite structures of MCU and client which applied to remote identification system. It has focused on analyzing the call establishment process and the process of opening or closing audio/video channel. After that, it provides a concrete realization of the system based on Open H.323.Finally, RTP/RTCP protocol is introduced which is used to transmit audio and video data. It especially analyzes three types of RTP encapsulation. The congestion control algorithm which is used usually on TCP is studied. A new algorithm is put forward. Three thresholds are set for estimating network state. According to packets loss rate from SR packets, network state is evaluated and bit rate is adjusted adaptively.