SIP Based Full Duplex Voice Communication In Multimedia Dispatching Scenario

With the development of the communication industry,it is possible to provide higher bandwidth.In order to promote the market,the trunked radio and scheduling industry need more scheduling business capabilities to make full use of bandwidth resources.According to this trend,referring to the development of mobile Internet,pictures and video are applied to the scheduling business,and the visualization has become a direction to promote the development of trunked industry.Based on such forward direction,this thesis expands the service application of the broadband trunked communication system to traditional voice services,and reasonably plans the business content.A new extension of the traditional half duplex voice service is proposed to provide full duplex digital voice power for the dispatcher.When the dispatcher needs real-time command and scheduling,the duplex audio with the single work video can provide a more convenient way of command in the field of real-time scheduling.Firstly,the session initiation protocol(SIP)and multimedia dispatching system(MDS)is introduced.As the theoretical basis of this paper,the technical characteristics and the message basic structure of the SIP are explained,along with its usage scenario and use method.After that is the introduction of the business model,function module and main process of the MDS that is the provider of the simplex video function for visual dispatching.Then,via analizations of the system requirements for full duplex voice function and the protocol stack technology for applications,the whole function and its subsystem are designed,and the function modules of independent design and the key related technologies are introduced,that is voice session management and voice conversation object.Next,the full duplex voice function is implemented module by module,including the detailed discriptions of the web page interaction design,the terminal logic processing,the special field recognition,the processing of signaling server,and the data structure and object relationship of the media server.Finally,the full duplex voice function is tested and analyzed,which demontrate that the full duplex voice function is achieved successfully,and the key process and message of interactive network are also consistent with the design expectations.This function has been integrated into the MDS,which will provide a richer user dispatching method for cluster.