Designing And Implementation Of Police Service Video Phone Based On SIP

With the modernization of public security department, it is necessary to improvethe cooperation ability and hadle sudden event ability, establish a police video phonesystem and provide platform for quick communication.This thesis proposes IP net of police as the unified bearing platform and provides apolice video phone system based on SIP procotol. The major function of the system isvideo phone communication. Product scheme for meeting interconnection of videospecial net, broadband internet and mobile internet, and communication security schemeare provided.This thesis proposes a solution of a police video phone based on SIP procotol afteranalysising requirments.This solution is based on Android phone platform. Comparingto features of H.323protocol, this thesis design using SIP as call signal stack so as toadapt NGN network. The solution provides call-control of the Video Phone with oSIPstack. RTP/RTCP is utilized to transmit audio/video stream and SIP procotol is utilizedfor phone call control, and the solution use MediaStreamer which is an open sourceproject to implement to transmit audio/video stream. The solution provides the real-timecommunication and encryption transmission of audio and video with SRTP module.Encryption function refers to hardware chip which supports SM4and AES encryption.The solution which supports encryption real-time communication is designed to run inAndroid platform on3G and WIFI network. At last, this thesis proposes result of systemtesting, including unit test of SIP module, RTP module and encryption module. Theauthor designs unit test, integrating test, method of voice quality measurement andcompatibility test. The sip phone works fine with Eyebeam sip phones in testing.The thesis analyzes the detailed requirements of system, and discusses how todesign SIP encryption communication system. Especially, it’s distinct with commonsoftware phone and implemented with hardware encryption. The thesis goes deep intothe practice optimization work, and be provided to the public police service system.Practice has proved that, the system can meet the police video communication system to security and flexible operational requirements.