Research And Development Of Voice Communication In DIMETRA Digital Trunked Dispatching System

DIMETRA digital trunked system, which is developed by Motorola company based on technology of TETRA IP, is an expandable 800MHz digital trunked communication system with many advantages such as quick access, flexible system, safe communication, reliable equipment and easy to extend. Thus it is suitable for each professional department to found dispatching communication network. At present, wireless dispatching communication in rail transportation sectors of Beijing, Shanghai, Xi'an and other major cities, has adopted DIMTRA IP solutions.Dispatching system is an important part in digital trunked communication system. Dispatchers can operate system resources directly on dispatching station, keep watch on important communication groups or single wireless user, and make the command and control quickly and conveniently. So, the design of dispatching system software will affect the efficiency of dispatching directly. At present, DIMETRA digital trunked system has adopted Centracom Elite dispatching system of Motorola company, but its function can not meet the domestic user's actual requirements completely.First of all, the thesis summarizes the feature of DIMETRA digital truncked system and its developing situation at home and aboard. Then, the thesis introduces the network structure, function design and working principle of dispatching system in detail. The voice dispatching software of dispatching system, whose functions include individual call, group call, multi-group call, emergency call and patch, is developed with MCC 7500 API provided by Motorola company. Finally, each voice function is tested in simulation environment and actual network, and the test result shows that the voice dispatching functions satisfy the design requirements.