Research And Implementation Of Video Transmission In Digital Trunked Dispatching Terminal Based On WiFi

The digital trunked system based on WiFi is a broadband digital trunked system,which is mainly used in the command and dispatch of hotel,inn and property,having potential dometic market.By using the terminal,the dispatcher can have voice and data communication with wireless users,in addition they can manage the trunked system resource.Adding video business into the dispatching terminal can increase the people's perception of the situation and information sharing ability of achieving higher command and dispatch.Hence,the video transmission in digital trunked dispatching terminal based on WiFi has very significant practical value.First,based on summarizing the development situation of video transmission in foreign dispatching terminal domestically and abroad,network architecture of digital trunked system based on WiFi,the composition of dispatching system,function of dispatching terminal and the video transmission of terminal are analyzed and the signaling process of login,logout and video transmission for dispatching terminal are described in datail in this paper.Then,the interface between dispatching temiinal and dispatching server,the interface between dispatching terminal and media gateway server are designed and the signal of login,logout and video transmission for dispatching terminal are defined and the key technology of receiving module,decryption module,decoding module,format transition module,playing module in video transmission is described and the main procedure of video transmission in dispatching terminal,initialization module,the interaction module of dispatching terminal and server and the processing procedure of video transmission module are provided.Next,based on Windows operation system,the main program of video transmission function for dispatching terminal,initialization module,the interaction module of dispatching terminal and server and the video transportation module are developed by using C++programming language in the Microsoft Visual Studio 2012 developing environment.It achieves the video transmission function between dispatching terminal and mobile terminal.Finally,the login and logout of dispatching terminal,the video call of dispatching terminal as main call and video call of dispatching terminal as being called are tested.The test result meets the design demand of the video transmission in digital trunked dispatching terminal based on WiFi.